October 2024 - Linux-stable-mirror

FAILED: patch "[PATCH] sched: psi: fix bogus pressure spikes from aggregation race" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 3840cbe24cf060ea05a585ca497814609f5d47d1 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100743-charity-wannabe-8c03@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: 3840cbe24cf0 ("sched: psi: fix bogus pressure spikes from aggregation race") ddae0ca2a8fe ("sched: Move psi_account_irqtime() out of update_rq_clock_task() hotpath") 0c2924079f5a ("sched/psi: Bail out early from irq time accounting") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 3840cbe24cf060ea05a585ca497814609f5d47d1 Mon Sep 17 00:00:00 2001 From: Johannes Weiner <hannes(a)cmpxchg.org> Date: Thu, 3 Oct 2024 07:29:05 -0400 Subject: [PATCH] sched: psi: fix bogus pressure spikes from aggregation race Brandon reports sporadic, non-sensical spikes in cumulative pressure time (total=) when reading cpu.pressure at a high rate. This is due to a race condition between reader aggregation and tasks changing states. While it affects all states and all resources captured by PSI, in practice it most likely triggers with CPU pressure, since scheduling events are so frequent compared to other resource events. The race context is the live snooping of ongoing stalls during a pressure read. The read aggregates per-cpu records for stalls that have concluded, but will also incorporate ad-hoc the duration of any active state that hasn't been recorded yet. This is important to get timely measurements of ongoing stalls. Those ad-hoc samples are calculated on-the-fly up to the current time on that CPU; since the stall hasn't concluded, it's expected that this is the minimum amount of stall time that will enter the per-cpu records once it does. The problem is that the path that concludes the state uses a CPU clock read that is not synchronized against aggregators; the clock is read outside of the seqlock protection. This allows aggregators to race and snoop a stall with a longer duration than will actually be recorded. With the recorded stall time being less than the last snapshot remembered by the aggregator, a subsequent sample will underflow and observe a bogus delta value, resulting in an erratic jump in pressure. Fix this by moving the clock read of the state change into the seqlock protection. This ensures no aggregation can snoop live stalls past the time that's recorded when the state concludes. Reported-by: Brandon Duffany <brandon(a)buildbuddy.io> Link: https://bugzilla.kernel.org/show_bug.cgi?id=219194 Link: https://lore.kernel.org/lkml/20240827121851.GB438928@cmpxchg.org/ Fixes: df77430639c9 ("psi: Reduce calls to sched_clock() in psi") Cc: stable(a)vger.kernel.org Signed-off-by: Johannes Weiner <hannes(a)cmpxchg.org> Reviewed-by: Chengming Zhou <chengming.zhou(a)linux.dev> Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 020d58967d4e..84dad1511d1e 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -769,12 +769,13 @@ static void record_times(struct psi_group_cpu *groupc, u64 now) } static void psi_group_change(struct psi_group *group, int cpu, - unsigned int clear, unsigned int set, u64 now, + unsigned int clear, unsigned int set, bool wake_clock) { struct psi_group_cpu *groupc; unsigned int t, m; u32 state_mask; + u64 now; lockdep_assert_rq_held(cpu_rq(cpu)); groupc = per_cpu_ptr(group->pcpu, cpu); @@ -789,6 +790,7 @@ static void psi_group_change(struct psi_group *group, int cpu, * SOME and FULL time these may have resulted in. */ write_seqcount_begin(&groupc->seq); + now = cpu_clock(cpu); /* * Start with TSK_ONCPU, which doesn't have a corresponding @@ -899,18 +901,15 @@ void psi_task_change(struct task_struct *task, int clear, int set) { int cpu = task_cpu(task); struct psi_group *group; - u64 now; if (!task->pid) return; psi_flags_change(task, clear, set); - now = cpu_clock(cpu); - group = task_psi_group(task); do { - psi_group_change(group, cpu, clear, set, now, true); + psi_group_change(group, cpu, clear, set, true); } while ((group = group->parent)); } @@ -919,7 +918,6 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, { struct psi_group *group, *common = NULL; int cpu = task_cpu(prev); - u64 now = cpu_clock(cpu); if (next->pid) { psi_flags_change(next, 0, TSK_ONCPU); @@ -936,7 +934,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, break; } - psi_group_change(group, cpu, 0, TSK_ONCPU, now, true); + psi_group_change(group, cpu, 0, TSK_ONCPU, true); } while ((group = group->parent)); } @@ -974,7 +972,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, do { if (group == common) break; - psi_group_change(group, cpu, clear, set, now, wake_clock); + psi_group_change(group, cpu, clear, set, wake_clock); } while ((group = group->parent)); /* @@ -986,7 +984,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, if ((prev->psi_flags ^ next->psi_flags) & ~TSK_ONCPU) { clear &= ~TSK_ONCPU; for (; group; group = group->parent) - psi_group_change(group, cpu, clear, set, now, wake_clock); + psi_group_change(group, cpu, clear, set, wake_clock); } } } @@ -997,8 +995,8 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st int cpu = task_cpu(curr); struct psi_group *group; struct psi_group_cpu *groupc; - u64 now, irq; s64 delta; + u64 irq; if (static_branch_likely(&psi_disabled)) return; @@ -1011,7 +1009,6 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st if (prev && task_psi_group(prev) == group) return; - now = cpu_clock(cpu); irq = irq_time_read(cpu); delta = (s64)(irq - rq->psi_irq_time); if (delta < 0) @@ -1019,12 +1016,15 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st rq->psi_irq_time = irq; do { + u64 now; + if (!group->enabled) continue; groupc = per_cpu_ptr(group->pcpu, cpu); write_seqcount_begin(&groupc->seq); + now = cpu_clock(cpu); record_times(groupc, now); groupc->times[PSI_IRQ_FULL] += delta; @@ -1223,11 +1223,9 @@ void psi_cgroup_restart(struct psi_group *group) for_each_possible_cpu(cpu) { struct rq *rq = cpu_rq(cpu); struct rq_flags rf; - u64 now; rq_lock_irq(rq, &rf); - now = cpu_clock(cpu); - psi_group_change(group, cpu, 0, 0, now, true); + psi_group_change(group, cpu, 0, 0, true); rq_unlock_irq(rq, &rf); } }

8 months, 4 weeks

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FAILED: patch "[PATCH] sched: psi: fix bogus pressure spikes from aggregation race" failed to apply to 6.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.10.y git checkout FETCH_HEAD git cherry-pick -x 3840cbe24cf060ea05a585ca497814609f5d47d1 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100742-manual-outright-b57d@gregkh' --subject-prefix 'PATCH 6.10.y' HEAD^.. Possible dependencies: 3840cbe24cf0 ("sched: psi: fix bogus pressure spikes from aggregation race") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 3840cbe24cf060ea05a585ca497814609f5d47d1 Mon Sep 17 00:00:00 2001 From: Johannes Weiner <hannes(a)cmpxchg.org> Date: Thu, 3 Oct 2024 07:29:05 -0400 Subject: [PATCH] sched: psi: fix bogus pressure spikes from aggregation race Brandon reports sporadic, non-sensical spikes in cumulative pressure time (total=) when reading cpu.pressure at a high rate. This is due to a race condition between reader aggregation and tasks changing states. While it affects all states and all resources captured by PSI, in practice it most likely triggers with CPU pressure, since scheduling events are so frequent compared to other resource events. The race context is the live snooping of ongoing stalls during a pressure read. The read aggregates per-cpu records for stalls that have concluded, but will also incorporate ad-hoc the duration of any active state that hasn't been recorded yet. This is important to get timely measurements of ongoing stalls. Those ad-hoc samples are calculated on-the-fly up to the current time on that CPU; since the stall hasn't concluded, it's expected that this is the minimum amount of stall time that will enter the per-cpu records once it does. The problem is that the path that concludes the state uses a CPU clock read that is not synchronized against aggregators; the clock is read outside of the seqlock protection. This allows aggregators to race and snoop a stall with a longer duration than will actually be recorded. With the recorded stall time being less than the last snapshot remembered by the aggregator, a subsequent sample will underflow and observe a bogus delta value, resulting in an erratic jump in pressure. Fix this by moving the clock read of the state change into the seqlock protection. This ensures no aggregation can snoop live stalls past the time that's recorded when the state concludes. Reported-by: Brandon Duffany <brandon(a)buildbuddy.io> Link: https://bugzilla.kernel.org/show_bug.cgi?id=219194 Link: https://lore.kernel.org/lkml/20240827121851.GB438928@cmpxchg.org/ Fixes: df77430639c9 ("psi: Reduce calls to sched_clock() in psi") Cc: stable(a)vger.kernel.org Signed-off-by: Johannes Weiner <hannes(a)cmpxchg.org> Reviewed-by: Chengming Zhou <chengming.zhou(a)linux.dev> Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 020d58967d4e..84dad1511d1e 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -769,12 +769,13 @@ static void record_times(struct psi_group_cpu *groupc, u64 now) } static void psi_group_change(struct psi_group *group, int cpu, - unsigned int clear, unsigned int set, u64 now, + unsigned int clear, unsigned int set, bool wake_clock) { struct psi_group_cpu *groupc; unsigned int t, m; u32 state_mask; + u64 now; lockdep_assert_rq_held(cpu_rq(cpu)); groupc = per_cpu_ptr(group->pcpu, cpu); @@ -789,6 +790,7 @@ static void psi_group_change(struct psi_group *group, int cpu, * SOME and FULL time these may have resulted in. */ write_seqcount_begin(&groupc->seq); + now = cpu_clock(cpu); /* * Start with TSK_ONCPU, which doesn't have a corresponding @@ -899,18 +901,15 @@ void psi_task_change(struct task_struct *task, int clear, int set) { int cpu = task_cpu(task); struct psi_group *group; - u64 now; if (!task->pid) return; psi_flags_change(task, clear, set); - now = cpu_clock(cpu); - group = task_psi_group(task); do { - psi_group_change(group, cpu, clear, set, now, true); + psi_group_change(group, cpu, clear, set, true); } while ((group = group->parent)); } @@ -919,7 +918,6 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, { struct psi_group *group, *common = NULL; int cpu = task_cpu(prev); - u64 now = cpu_clock(cpu); if (next->pid) { psi_flags_change(next, 0, TSK_ONCPU); @@ -936,7 +934,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, break; } - psi_group_change(group, cpu, 0, TSK_ONCPU, now, true); + psi_group_change(group, cpu, 0, TSK_ONCPU, true); } while ((group = group->parent)); } @@ -974,7 +972,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, do { if (group == common) break; - psi_group_change(group, cpu, clear, set, now, wake_clock); + psi_group_change(group, cpu, clear, set, wake_clock); } while ((group = group->parent)); /* @@ -986,7 +984,7 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, if ((prev->psi_flags ^ next->psi_flags) & ~TSK_ONCPU) { clear &= ~TSK_ONCPU; for (; group; group = group->parent) - psi_group_change(group, cpu, clear, set, now, wake_clock); + psi_group_change(group, cpu, clear, set, wake_clock); } } } @@ -997,8 +995,8 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st int cpu = task_cpu(curr); struct psi_group *group; struct psi_group_cpu *groupc; - u64 now, irq; s64 delta; + u64 irq; if (static_branch_likely(&psi_disabled)) return; @@ -1011,7 +1009,6 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st if (prev && task_psi_group(prev) == group) return; - now = cpu_clock(cpu); irq = irq_time_read(cpu); delta = (s64)(irq - rq->psi_irq_time); if (delta < 0) @@ -1019,12 +1016,15 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st rq->psi_irq_time = irq; do { + u64 now; + if (!group->enabled) continue; groupc = per_cpu_ptr(group->pcpu, cpu); write_seqcount_begin(&groupc->seq); + now = cpu_clock(cpu); record_times(groupc, now); groupc->times[PSI_IRQ_FULL] += delta; @@ -1223,11 +1223,9 @@ void psi_cgroup_restart(struct psi_group *group) for_each_possible_cpu(cpu) { struct rq *rq = cpu_rq(cpu); struct rq_flags rf; - u64 now; rq_lock_irq(rq, &rf); - now = cpu_clock(cpu); - psi_group_change(group, cpu, 0, 0, now, true); + psi_group_change(group, cpu, 0, 0, true); rq_unlock_irq(rq, &rf); } }

8 months, 4 weeks

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FAILED: patch "[PATCH] drm/xe: fix UAF around queue destruction" failed to apply to 6.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.10.y git checkout FETCH_HEAD git cherry-pick -x 2d2be279f1ca9e7288282d4214f16eea8a727cdb # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100727-lego-panther-fea9@gregkh' --subject-prefix 'PATCH 6.10.y' HEAD^.. Possible dependencies: 2d2be279f1ca ("drm/xe: fix UAF around queue destruction") 3f371a98dead ("drm/xe: Delete unused GuC submission_state.suspend") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 2d2be279f1ca9e7288282d4214f16eea8a727cdb Mon Sep 17 00:00:00 2001 From: Matthew Auld <matthew.auld(a)intel.com> Date: Mon, 23 Sep 2024 15:56:48 +0100 Subject: [PATCH] drm/xe: fix UAF around queue destruction We currently do stuff like queuing the final destruction step on a random system wq, which will outlive the driver instance. With bad timing we can teardown the driver with one or more work workqueue still being alive leading to various UAF splats. Add a fini step to ensure user queues are properly torn down. At this point GuC should already be nuked so queue itself should no longer be referenced from hw pov. v2 (Matt B) - Looks much safer to use a waitqueue and then just wait for the xa_array to become empty before triggering the drain. Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2317 Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs") Signed-off-by: Matthew Auld <matthew.auld(a)intel.com> Cc: Matthew Brost <matthew.brost(a)intel.com> Cc: <stable(a)vger.kernel.org> # v6.8+ Reviewed-by: Matthew Brost <matthew.brost(a)intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20240923145647.77707-2-matthe… (cherry picked from commit 861108666cc0e999cffeab6aff17b662e68774e3) Signed-off-by: Lucas De Marchi <lucas.demarchi(a)intel.com> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c index 70d4e4d46c3c..74e593caf87c 100644 --- a/drivers/gpu/drm/xe/xe_device.c +++ b/drivers/gpu/drm/xe/xe_device.c @@ -298,6 +298,9 @@ static void xe_device_destroy(struct drm_device *dev, void *dummy) if (xe->unordered_wq) destroy_workqueue(xe->unordered_wq); + if (xe->destroy_wq) + destroy_workqueue(xe->destroy_wq); + ttm_device_fini(&xe->ttm); } @@ -363,8 +366,9 @@ struct xe_device *xe_device_create(struct pci_dev *pdev, xe->preempt_fence_wq = alloc_ordered_workqueue("xe-preempt-fence-wq", 0); xe->ordered_wq = alloc_ordered_workqueue("xe-ordered-wq", 0); xe->unordered_wq = alloc_workqueue("xe-unordered-wq", 0, 0); + xe->destroy_wq = alloc_workqueue("xe-destroy-wq", 0, 0); if (!xe->ordered_wq || !xe->unordered_wq || - !xe->preempt_fence_wq) { + !xe->preempt_fence_wq || !xe->destroy_wq) { /* * Cleanup done in xe_device_destroy via * drmm_add_action_or_reset register above diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h index ec7eb7811126..24c8c2d20676 100644 --- a/drivers/gpu/drm/xe/xe_device_types.h +++ b/drivers/gpu/drm/xe/xe_device_types.h @@ -396,6 +396,9 @@ struct xe_device { /** @unordered_wq: used to serialize unordered work, mostly display */ struct workqueue_struct *unordered_wq; + /** @destroy_wq: used to serialize user destroy work, like queue */ + struct workqueue_struct *destroy_wq; + /** @tiles: device tiles */ struct xe_tile tiles[XE_MAX_TILES_PER_DEVICE]; diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c index 715c761dc7d6..98a6a385a796 100644 --- a/drivers/gpu/drm/xe/xe_guc_submit.c +++ b/drivers/gpu/drm/xe/xe_guc_submit.c @@ -276,10 +276,26 @@ static struct workqueue_struct *get_submit_wq(struct xe_guc *guc) } #endif +static void xe_guc_submit_fini(struct xe_guc *guc) +{ + struct xe_device *xe = guc_to_xe(guc); + struct xe_gt *gt = guc_to_gt(guc); + int ret; + + ret = wait_event_timeout(guc->submission_state.fini_wq, + xa_empty(&guc->submission_state.exec_queue_lookup), + HZ * 5); + + drain_workqueue(xe->destroy_wq); + + xe_gt_assert(gt, ret); +} + static void guc_submit_fini(struct drm_device *drm, void *arg) { struct xe_guc *guc = arg; + xe_guc_submit_fini(guc); xa_destroy(&guc->submission_state.exec_queue_lookup); free_submit_wq(guc); } @@ -351,6 +367,8 @@ int xe_guc_submit_init(struct xe_guc *guc, unsigned int num_ids) xa_init(&guc->submission_state.exec_queue_lookup); + init_waitqueue_head(&guc->submission_state.fini_wq); + primelockdep(guc); return drmm_add_action_or_reset(&xe->drm, guc_submit_fini, guc); @@ -367,6 +385,9 @@ static void __release_guc_id(struct xe_guc *guc, struct xe_exec_queue *q, u32 xa xe_guc_id_mgr_release_locked(&guc->submission_state.idm, q->guc->id, q->width); + + if (xa_empty(&guc->submission_state.exec_queue_lookup)) + wake_up(&guc->submission_state.fini_wq); } static int alloc_guc_id(struct xe_guc *guc, struct xe_exec_queue *q) @@ -1274,13 +1295,16 @@ static void __guc_exec_queue_fini_async(struct work_struct *w) static void guc_exec_queue_fini_async(struct xe_exec_queue *q) { + struct xe_guc *guc = exec_queue_to_guc(q); + struct xe_device *xe = guc_to_xe(guc); + INIT_WORK(&q->guc->fini_async, __guc_exec_queue_fini_async); /* We must block on kernel engines so slabs are empty on driver unload */ if (q->flags & EXEC_QUEUE_FLAG_PERMANENT || exec_queue_wedged(q)) __guc_exec_queue_fini_async(&q->guc->fini_async); else - queue_work(system_wq, &q->guc->fini_async); + queue_work(xe->destroy_wq, &q->guc->fini_async); } static void __guc_exec_queue_fini(struct xe_guc *guc, struct xe_exec_queue *q) diff --git a/drivers/gpu/drm/xe/xe_guc_types.h b/drivers/gpu/drm/xe/xe_guc_types.h index 546ac6350a31..69046f698271 100644 --- a/drivers/gpu/drm/xe/xe_guc_types.h +++ b/drivers/gpu/drm/xe/xe_guc_types.h @@ -81,6 +81,8 @@ struct xe_guc { #endif /** @submission_state.enabled: submission is enabled */ bool enabled; + /** @submission_state.fini_wq: submit fini wait queue */ + wait_queue_head_t fini_wq; } submission_state; /** @hwconfig: Hardware config state */ struct {

8 months, 4 weeks

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[PATCH v2 0/3] Bluetooth: Fix a few module init/deinit bugs

by Aaron Thompson

Hi all, These patches fix a few bugs in init and deinit for the bluetooth module. I ran into the first one when I started running a kernel with debugfs disabled on my laptop, and I ran into the next two when I was working on the fix for the first one. v2: * Move iso_exit() call to bt_exit() (Luiz Augusto von Dentz) Aaron Thompson (3): Bluetooth: ISO: Fix multiple init when debugfs is disabled Bluetooth: Call iso_exit() on module unload Bluetooth: Remove debugfs directory on module init failure net/bluetooth/af_bluetooth.c | 3 +++ net/bluetooth/iso.c | 6 +----- 2 files changed, 4 insertions(+), 5 deletions(-) base-commit: 9852d85ec9d492ebef56dc5f229416c925758edc -- 2.39.5

8 months, 4 weeks

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FAILED: patch "[PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 7a2369b74abf76cd3e54c45b30f6addb497f831b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100717-unbolted-bounce-cdf9@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: 7a2369b74abf ("mm: z3fold: deprecate CONFIG_Z3FOLD") 04cb7502a5d7 ("zsmalloc: use all available 24 bits of page_type") 43d746dc49bb ("mm/zsmalloc: use a proper page type") 8db00ad56461 ("mm: allow reuse of the lower 16 bit of the page type with an actual type") 6d21dde7adc0 ("mm: update _mapcount and page_type documentation") ff202303c398 ("mm: convert page type macros to enum") 46df8e73a4a3 ("mm: free up PG_slab") d99e3140a4d3 ("mm: turn folio_test_hugetlb into a PageType") fd1a745ce03e ("mm: support page_mapcount() on page_has_type() pages") 29cfe7556bfd ("mm: constify more page/folio tests") 443cbaf9e2fd ("crash: split vmcoreinfo exporting code out from crash_core.c") 85fcde402db1 ("kexec: split crashkernel reservation code out from crash_core.c") 55c49fee57af ("mm/vmalloc: remove vmap_area_list") d093602919ad ("mm: vmalloc: remove global vmap_area_root rb-tree") 7fa8cee00316 ("mm: vmalloc: move vmap_init_free_space() down in vmalloc.c") 4a693ce65b18 ("kdump: defer the insertion of crashkernel resources") 9f2a63523582 ("Merge tag 'mm-nonmm-stable-2024-01-09-10-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7a2369b74abf76cd3e54c45b30f6addb497f831b Mon Sep 17 00:00:00 2001 From: Yosry Ahmed <yosryahmed(a)google.com> Date: Wed, 4 Sep 2024 23:33:43 +0000 Subject: [PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD The z3fold compressed pages allocator is rarely used, most users use zsmalloc. The only disadvantage of zsmalloc in comparison is the dependency on MMU, and zbud is a more common option for !MMU as it was the default zswap allocator for a long time. Historically, zsmalloc had worse latency than zbud and z3fold but offered better memory savings. This is no longer the case as shown by a simple recent analysis [1]. That analysis showed that z3fold does not have any advantage over zsmalloc or zbud considering both performance and memory usage. In a kernel build test on tmpfs in a limited cgroup, z3fold took 3% more time and used 1.8% more memory. The latency of zswap_load() was 7% higher, and that of zswap_store() was 10% higher. Zsmalloc is better in all metrics. Moreover, z3fold apparently has latent bugs, which was made noticeable by a recent soft lockup bug report with z3fold [2]. Switching to zsmalloc not only fixed the problem, but also reduced the swap usage from 6~8G to 1~2G. Other users have also reported being bitten by mistakenly enabling z3fold. Other than hurting users, z3fold is repeatedly causing wasted engineering effort. Apart from investigating the above bug, it came up in multiple development discussions (e.g. [3]) as something we need to handle, when there aren't any legit users (at least not intentionally). The natural course of action is to deprecate z3fold, and remove in a few cycles if no objections are raised from active users. Next on the list should be zbud, as it offers marginal latency gains at the cost of huge memory waste when compared to zsmalloc. That one will need to wait until zsmalloc does not depend on MMU. Rename the user-visible config option from CONFIG_Z3FOLD to CONFIG_Z3FOLD_DEPRECATED so that users with CONFIG_Z3FOLD=y get a new prompt with explanation during make oldconfig. Also, remove CONFIG_Z3FOLD=y from defconfigs. [1]https://lore.kernel.org/lkml/CAJD7tkbRF6od-2x_L8-A1QL3=2Ww13sCj4S3i4bNndq… [2]https://lore.kernel.org/lkml/EF0ABD3E-A239-4111-A8AB-5C442E759CF3@gmail.c… [3]https://lore.kernel.org/lkml/CAJD7tkbnmeVugfunffSovJf9FAgy9rhBVt_tx=nxUve… [arnd(a)arndb.de: deprecate ZSWAP_ZPOOL_DEFAULT_Z3FOLD as well] Link: https://lkml.kernel.org/r/20240909202625.1054880-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20240904233343.933462-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed(a)google.com> Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> Acked-by: Chris Down <chris(a)chrisdown.name> Acked-by: Nhat Pham <nphamcs(a)gmail.com> Acked-by: Johannes Weiner <hannes(a)cmpxchg.org> Acked-by: Vitaly Wool <vitaly.wool(a)konsulko.com> Acked-by: Christoph Hellwig <hch(a)lst.de> Cc: Aneesh Kumar K.V <aneesh.kumar(a)kernel.org> Cc: Christophe Leroy <christophe.leroy(a)csgroup.eu> Cc: Huacai Chen <chenhuacai(a)kernel.org> Cc: Miaohe Lin <linmiaohe(a)huawei.com> Cc: Michael Ellerman <mpe(a)ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao(a)linux.ibm.com> Cc: Nicholas Piggin <npiggin(a)gmail.com> Cc: Sergey Senozhatsky <senozhatsky(a)chromium.org> Cc: WANG Xuerui <kernel(a)xen0n.name> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig index b4252c357c8e..75b366407a60 100644 --- a/arch/loongarch/configs/loongson3_defconfig +++ b/arch/loongarch/configs/loongson3_defconfig @@ -96,7 +96,6 @@ CONFIG_ZPOOL=y CONFIG_ZSWAP=y CONFIG_ZSWAP_COMPRESSOR_DEFAULT_ZSTD=y CONFIG_ZBUD=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=m # CONFIG_COMPAT_BRK is not set CONFIG_MEMORY_HOTPLUG=y diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig index 544a65fda77b..d39284489aa2 100644 --- a/arch/powerpc/configs/ppc64_defconfig +++ b/arch/powerpc/configs/ppc64_defconfig @@ -81,7 +81,6 @@ CONFIG_MODULE_SIG_SHA512=y CONFIG_PARTITION_ADVANCED=y CONFIG_BINFMT_MISC=m CONFIG_ZSWAP=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=y # CONFIG_SLAB_MERGE_DEFAULT is not set CONFIG_SLAB_FREELIST_RANDOM=y diff --git a/mm/Kconfig b/mm/Kconfig index 1aa282e35dc7..09aebca1cae3 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -146,12 +146,15 @@ config ZSWAP_ZPOOL_DEFAULT_ZBUD help Use the zbud allocator as the default allocator. -config ZSWAP_ZPOOL_DEFAULT_Z3FOLD - bool "z3fold" - select Z3FOLD +config ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED + bool "z3foldi (DEPRECATED)" + select Z3FOLD_DEPRECATED help Use the z3fold allocator as the default allocator. + Deprecated and scheduled for removal in a few cycles, + see CONFIG_Z3FOLD_DEPRECATED. + config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC bool "zsmalloc" select ZSMALLOC @@ -163,7 +166,7 @@ config ZSWAP_ZPOOL_DEFAULT string depends on ZSWAP default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD - default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD + default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC default "" @@ -177,15 +180,25 @@ config ZBUD deterministic reclaim properties that make it preferable to a higher density approach when reclaim will be used. -config Z3FOLD - tristate "3:1 compression allocator (z3fold)" +config Z3FOLD_DEPRECATED + tristate "3:1 compression allocator (z3fold) (DEPRECATED)" depends on ZSWAP help + Deprecated and scheduled for removal in a few cycles. If you have + a good reason for using Z3FOLD over ZSMALLOC, please contact + linux-mm(a)kvack.org and the zswap maintainers. + A special purpose allocator for storing compressed pages. It is designed to store up to three compressed pages per physical page. It is a ZBUD derivative so the simplicity and determinism are still there. +config Z3FOLD + tristate + default y if Z3FOLD_DEPRECATED=y + default m if Z3FOLD_DEPRECATED=m + depends on Z3FOLD_DEPRECATED + config ZSMALLOC tristate prompt "N:1 compression allocator (zsmalloc)" if (ZSWAP || ZRAM)

8 months, 4 weeks

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0
0 0

FAILED: patch "[PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 7a2369b74abf76cd3e54c45b30f6addb497f831b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100716-bullish-drove-0517@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: 7a2369b74abf ("mm: z3fold: deprecate CONFIG_Z3FOLD") 04cb7502a5d7 ("zsmalloc: use all available 24 bits of page_type") 43d746dc49bb ("mm/zsmalloc: use a proper page type") 8db00ad56461 ("mm: allow reuse of the lower 16 bit of the page type with an actual type") 6d21dde7adc0 ("mm: update _mapcount and page_type documentation") ff202303c398 ("mm: convert page type macros to enum") 46df8e73a4a3 ("mm: free up PG_slab") d99e3140a4d3 ("mm: turn folio_test_hugetlb into a PageType") fd1a745ce03e ("mm: support page_mapcount() on page_has_type() pages") 29cfe7556bfd ("mm: constify more page/folio tests") 443cbaf9e2fd ("crash: split vmcoreinfo exporting code out from crash_core.c") 85fcde402db1 ("kexec: split crashkernel reservation code out from crash_core.c") 55c49fee57af ("mm/vmalloc: remove vmap_area_list") d093602919ad ("mm: vmalloc: remove global vmap_area_root rb-tree") 7fa8cee00316 ("mm: vmalloc: move vmap_init_free_space() down in vmalloc.c") 4a693ce65b18 ("kdump: defer the insertion of crashkernel resources") 9f2a63523582 ("Merge tag 'mm-nonmm-stable-2024-01-09-10-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7a2369b74abf76cd3e54c45b30f6addb497f831b Mon Sep 17 00:00:00 2001 From: Yosry Ahmed <yosryahmed(a)google.com> Date: Wed, 4 Sep 2024 23:33:43 +0000 Subject: [PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD The z3fold compressed pages allocator is rarely used, most users use zsmalloc. The only disadvantage of zsmalloc in comparison is the dependency on MMU, and zbud is a more common option for !MMU as it was the default zswap allocator for a long time. Historically, zsmalloc had worse latency than zbud and z3fold but offered better memory savings. This is no longer the case as shown by a simple recent analysis [1]. That analysis showed that z3fold does not have any advantage over zsmalloc or zbud considering both performance and memory usage. In a kernel build test on tmpfs in a limited cgroup, z3fold took 3% more time and used 1.8% more memory. The latency of zswap_load() was 7% higher, and that of zswap_store() was 10% higher. Zsmalloc is better in all metrics. Moreover, z3fold apparently has latent bugs, which was made noticeable by a recent soft lockup bug report with z3fold [2]. Switching to zsmalloc not only fixed the problem, but also reduced the swap usage from 6~8G to 1~2G. Other users have also reported being bitten by mistakenly enabling z3fold. Other than hurting users, z3fold is repeatedly causing wasted engineering effort. Apart from investigating the above bug, it came up in multiple development discussions (e.g. [3]) as something we need to handle, when there aren't any legit users (at least not intentionally). The natural course of action is to deprecate z3fold, and remove in a few cycles if no objections are raised from active users. Next on the list should be zbud, as it offers marginal latency gains at the cost of huge memory waste when compared to zsmalloc. That one will need to wait until zsmalloc does not depend on MMU. Rename the user-visible config option from CONFIG_Z3FOLD to CONFIG_Z3FOLD_DEPRECATED so that users with CONFIG_Z3FOLD=y get a new prompt with explanation during make oldconfig. Also, remove CONFIG_Z3FOLD=y from defconfigs. [1]https://lore.kernel.org/lkml/CAJD7tkbRF6od-2x_L8-A1QL3=2Ww13sCj4S3i4bNndq… [2]https://lore.kernel.org/lkml/EF0ABD3E-A239-4111-A8AB-5C442E759CF3@gmail.c… [3]https://lore.kernel.org/lkml/CAJD7tkbnmeVugfunffSovJf9FAgy9rhBVt_tx=nxUve… [arnd(a)arndb.de: deprecate ZSWAP_ZPOOL_DEFAULT_Z3FOLD as well] Link: https://lkml.kernel.org/r/20240909202625.1054880-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20240904233343.933462-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed(a)google.com> Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> Acked-by: Chris Down <chris(a)chrisdown.name> Acked-by: Nhat Pham <nphamcs(a)gmail.com> Acked-by: Johannes Weiner <hannes(a)cmpxchg.org> Acked-by: Vitaly Wool <vitaly.wool(a)konsulko.com> Acked-by: Christoph Hellwig <hch(a)lst.de> Cc: Aneesh Kumar K.V <aneesh.kumar(a)kernel.org> Cc: Christophe Leroy <christophe.leroy(a)csgroup.eu> Cc: Huacai Chen <chenhuacai(a)kernel.org> Cc: Miaohe Lin <linmiaohe(a)huawei.com> Cc: Michael Ellerman <mpe(a)ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao(a)linux.ibm.com> Cc: Nicholas Piggin <npiggin(a)gmail.com> Cc: Sergey Senozhatsky <senozhatsky(a)chromium.org> Cc: WANG Xuerui <kernel(a)xen0n.name> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig index b4252c357c8e..75b366407a60 100644 --- a/arch/loongarch/configs/loongson3_defconfig +++ b/arch/loongarch/configs/loongson3_defconfig @@ -96,7 +96,6 @@ CONFIG_ZPOOL=y CONFIG_ZSWAP=y CONFIG_ZSWAP_COMPRESSOR_DEFAULT_ZSTD=y CONFIG_ZBUD=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=m # CONFIG_COMPAT_BRK is not set CONFIG_MEMORY_HOTPLUG=y diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig index 544a65fda77b..d39284489aa2 100644 --- a/arch/powerpc/configs/ppc64_defconfig +++ b/arch/powerpc/configs/ppc64_defconfig @@ -81,7 +81,6 @@ CONFIG_MODULE_SIG_SHA512=y CONFIG_PARTITION_ADVANCED=y CONFIG_BINFMT_MISC=m CONFIG_ZSWAP=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=y # CONFIG_SLAB_MERGE_DEFAULT is not set CONFIG_SLAB_FREELIST_RANDOM=y diff --git a/mm/Kconfig b/mm/Kconfig index 1aa282e35dc7..09aebca1cae3 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -146,12 +146,15 @@ config ZSWAP_ZPOOL_DEFAULT_ZBUD help Use the zbud allocator as the default allocator. -config ZSWAP_ZPOOL_DEFAULT_Z3FOLD - bool "z3fold" - select Z3FOLD +config ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED + bool "z3foldi (DEPRECATED)" + select Z3FOLD_DEPRECATED help Use the z3fold allocator as the default allocator. + Deprecated and scheduled for removal in a few cycles, + see CONFIG_Z3FOLD_DEPRECATED. + config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC bool "zsmalloc" select ZSMALLOC @@ -163,7 +166,7 @@ config ZSWAP_ZPOOL_DEFAULT string depends on ZSWAP default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD - default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD + default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC default "" @@ -177,15 +180,25 @@ config ZBUD deterministic reclaim properties that make it preferable to a higher density approach when reclaim will be used. -config Z3FOLD - tristate "3:1 compression allocator (z3fold)" +config Z3FOLD_DEPRECATED + tristate "3:1 compression allocator (z3fold) (DEPRECATED)" depends on ZSWAP help + Deprecated and scheduled for removal in a few cycles. If you have + a good reason for using Z3FOLD over ZSMALLOC, please contact + linux-mm(a)kvack.org and the zswap maintainers. + A special purpose allocator for storing compressed pages. It is designed to store up to three compressed pages per physical page. It is a ZBUD derivative so the simplicity and determinism are still there. +config Z3FOLD + tristate + default y if Z3FOLD_DEPRECATED=y + default m if Z3FOLD_DEPRECATED=m + depends on Z3FOLD_DEPRECATED + config ZSMALLOC tristate prompt "N:1 compression allocator (zsmalloc)" if (ZSWAP || ZRAM)

8 months, 4 weeks

1
0
0 0

FAILED: patch "[PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 7a2369b74abf76cd3e54c45b30f6addb497f831b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100714-schedule-humpback-1b89@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: 7a2369b74abf ("mm: z3fold: deprecate CONFIG_Z3FOLD") 04cb7502a5d7 ("zsmalloc: use all available 24 bits of page_type") 43d746dc49bb ("mm/zsmalloc: use a proper page type") 8db00ad56461 ("mm: allow reuse of the lower 16 bit of the page type with an actual type") 6d21dde7adc0 ("mm: update _mapcount and page_type documentation") ff202303c398 ("mm: convert page type macros to enum") 46df8e73a4a3 ("mm: free up PG_slab") d99e3140a4d3 ("mm: turn folio_test_hugetlb into a PageType") fd1a745ce03e ("mm: support page_mapcount() on page_has_type() pages") 29cfe7556bfd ("mm: constify more page/folio tests") 443cbaf9e2fd ("crash: split vmcoreinfo exporting code out from crash_core.c") 85fcde402db1 ("kexec: split crashkernel reservation code out from crash_core.c") 55c49fee57af ("mm/vmalloc: remove vmap_area_list") d093602919ad ("mm: vmalloc: remove global vmap_area_root rb-tree") 7fa8cee00316 ("mm: vmalloc: move vmap_init_free_space() down in vmalloc.c") 4a693ce65b18 ("kdump: defer the insertion of crashkernel resources") 9f2a63523582 ("Merge tag 'mm-nonmm-stable-2024-01-09-10-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7a2369b74abf76cd3e54c45b30f6addb497f831b Mon Sep 17 00:00:00 2001 From: Yosry Ahmed <yosryahmed(a)google.com> Date: Wed, 4 Sep 2024 23:33:43 +0000 Subject: [PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD The z3fold compressed pages allocator is rarely used, most users use zsmalloc. The only disadvantage of zsmalloc in comparison is the dependency on MMU, and zbud is a more common option for !MMU as it was the default zswap allocator for a long time. Historically, zsmalloc had worse latency than zbud and z3fold but offered better memory savings. This is no longer the case as shown by a simple recent analysis [1]. That analysis showed that z3fold does not have any advantage over zsmalloc or zbud considering both performance and memory usage. In a kernel build test on tmpfs in a limited cgroup, z3fold took 3% more time and used 1.8% more memory. The latency of zswap_load() was 7% higher, and that of zswap_store() was 10% higher. Zsmalloc is better in all metrics. Moreover, z3fold apparently has latent bugs, which was made noticeable by a recent soft lockup bug report with z3fold [2]. Switching to zsmalloc not only fixed the problem, but also reduced the swap usage from 6~8G to 1~2G. Other users have also reported being bitten by mistakenly enabling z3fold. Other than hurting users, z3fold is repeatedly causing wasted engineering effort. Apart from investigating the above bug, it came up in multiple development discussions (e.g. [3]) as something we need to handle, when there aren't any legit users (at least not intentionally). The natural course of action is to deprecate z3fold, and remove in a few cycles if no objections are raised from active users. Next on the list should be zbud, as it offers marginal latency gains at the cost of huge memory waste when compared to zsmalloc. That one will need to wait until zsmalloc does not depend on MMU. Rename the user-visible config option from CONFIG_Z3FOLD to CONFIG_Z3FOLD_DEPRECATED so that users with CONFIG_Z3FOLD=y get a new prompt with explanation during make oldconfig. Also, remove CONFIG_Z3FOLD=y from defconfigs. [1]https://lore.kernel.org/lkml/CAJD7tkbRF6od-2x_L8-A1QL3=2Ww13sCj4S3i4bNndq… [2]https://lore.kernel.org/lkml/EF0ABD3E-A239-4111-A8AB-5C442E759CF3@gmail.c… [3]https://lore.kernel.org/lkml/CAJD7tkbnmeVugfunffSovJf9FAgy9rhBVt_tx=nxUve… [arnd(a)arndb.de: deprecate ZSWAP_ZPOOL_DEFAULT_Z3FOLD as well] Link: https://lkml.kernel.org/r/20240909202625.1054880-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20240904233343.933462-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed(a)google.com> Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> Acked-by: Chris Down <chris(a)chrisdown.name> Acked-by: Nhat Pham <nphamcs(a)gmail.com> Acked-by: Johannes Weiner <hannes(a)cmpxchg.org> Acked-by: Vitaly Wool <vitaly.wool(a)konsulko.com> Acked-by: Christoph Hellwig <hch(a)lst.de> Cc: Aneesh Kumar K.V <aneesh.kumar(a)kernel.org> Cc: Christophe Leroy <christophe.leroy(a)csgroup.eu> Cc: Huacai Chen <chenhuacai(a)kernel.org> Cc: Miaohe Lin <linmiaohe(a)huawei.com> Cc: Michael Ellerman <mpe(a)ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao(a)linux.ibm.com> Cc: Nicholas Piggin <npiggin(a)gmail.com> Cc: Sergey Senozhatsky <senozhatsky(a)chromium.org> Cc: WANG Xuerui <kernel(a)xen0n.name> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig index b4252c357c8e..75b366407a60 100644 --- a/arch/loongarch/configs/loongson3_defconfig +++ b/arch/loongarch/configs/loongson3_defconfig @@ -96,7 +96,6 @@ CONFIG_ZPOOL=y CONFIG_ZSWAP=y CONFIG_ZSWAP_COMPRESSOR_DEFAULT_ZSTD=y CONFIG_ZBUD=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=m # CONFIG_COMPAT_BRK is not set CONFIG_MEMORY_HOTPLUG=y diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig index 544a65fda77b..d39284489aa2 100644 --- a/arch/powerpc/configs/ppc64_defconfig +++ b/arch/powerpc/configs/ppc64_defconfig @@ -81,7 +81,6 @@ CONFIG_MODULE_SIG_SHA512=y CONFIG_PARTITION_ADVANCED=y CONFIG_BINFMT_MISC=m CONFIG_ZSWAP=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=y # CONFIG_SLAB_MERGE_DEFAULT is not set CONFIG_SLAB_FREELIST_RANDOM=y diff --git a/mm/Kconfig b/mm/Kconfig index 1aa282e35dc7..09aebca1cae3 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -146,12 +146,15 @@ config ZSWAP_ZPOOL_DEFAULT_ZBUD help Use the zbud allocator as the default allocator. -config ZSWAP_ZPOOL_DEFAULT_Z3FOLD - bool "z3fold" - select Z3FOLD +config ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED + bool "z3foldi (DEPRECATED)" + select Z3FOLD_DEPRECATED help Use the z3fold allocator as the default allocator. + Deprecated and scheduled for removal in a few cycles, + see CONFIG_Z3FOLD_DEPRECATED. + config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC bool "zsmalloc" select ZSMALLOC @@ -163,7 +166,7 @@ config ZSWAP_ZPOOL_DEFAULT string depends on ZSWAP default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD - default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD + default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC default "" @@ -177,15 +180,25 @@ config ZBUD deterministic reclaim properties that make it preferable to a higher density approach when reclaim will be used. -config Z3FOLD - tristate "3:1 compression allocator (z3fold)" +config Z3FOLD_DEPRECATED + tristate "3:1 compression allocator (z3fold) (DEPRECATED)" depends on ZSWAP help + Deprecated and scheduled for removal in a few cycles. If you have + a good reason for using Z3FOLD over ZSMALLOC, please contact + linux-mm(a)kvack.org and the zswap maintainers. + A special purpose allocator for storing compressed pages. It is designed to store up to three compressed pages per physical page. It is a ZBUD derivative so the simplicity and determinism are still there. +config Z3FOLD + tristate + default y if Z3FOLD_DEPRECATED=y + default m if Z3FOLD_DEPRECATED=m + depends on Z3FOLD_DEPRECATED + config ZSMALLOC tristate prompt "N:1 compression allocator (zsmalloc)" if (ZSWAP || ZRAM)

8 months, 4 weeks

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0
0 0

FAILED: patch "[PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 7a2369b74abf76cd3e54c45b30f6addb497f831b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100713-amusable-tripping-65d1@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: 7a2369b74abf ("mm: z3fold: deprecate CONFIG_Z3FOLD") 04cb7502a5d7 ("zsmalloc: use all available 24 bits of page_type") 43d746dc49bb ("mm/zsmalloc: use a proper page type") 8db00ad56461 ("mm: allow reuse of the lower 16 bit of the page type with an actual type") 6d21dde7adc0 ("mm: update _mapcount and page_type documentation") ff202303c398 ("mm: convert page type macros to enum") 46df8e73a4a3 ("mm: free up PG_slab") d99e3140a4d3 ("mm: turn folio_test_hugetlb into a PageType") fd1a745ce03e ("mm: support page_mapcount() on page_has_type() pages") 29cfe7556bfd ("mm: constify more page/folio tests") 443cbaf9e2fd ("crash: split vmcoreinfo exporting code out from crash_core.c") 85fcde402db1 ("kexec: split crashkernel reservation code out from crash_core.c") 55c49fee57af ("mm/vmalloc: remove vmap_area_list") d093602919ad ("mm: vmalloc: remove global vmap_area_root rb-tree") 7fa8cee00316 ("mm: vmalloc: move vmap_init_free_space() down in vmalloc.c") 4a693ce65b18 ("kdump: defer the insertion of crashkernel resources") 9f2a63523582 ("Merge tag 'mm-nonmm-stable-2024-01-09-10-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7a2369b74abf76cd3e54c45b30f6addb497f831b Mon Sep 17 00:00:00 2001 From: Yosry Ahmed <yosryahmed(a)google.com> Date: Wed, 4 Sep 2024 23:33:43 +0000 Subject: [PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD The z3fold compressed pages allocator is rarely used, most users use zsmalloc. The only disadvantage of zsmalloc in comparison is the dependency on MMU, and zbud is a more common option for !MMU as it was the default zswap allocator for a long time. Historically, zsmalloc had worse latency than zbud and z3fold but offered better memory savings. This is no longer the case as shown by a simple recent analysis [1]. That analysis showed that z3fold does not have any advantage over zsmalloc or zbud considering both performance and memory usage. In a kernel build test on tmpfs in a limited cgroup, z3fold took 3% more time and used 1.8% more memory. The latency of zswap_load() was 7% higher, and that of zswap_store() was 10% higher. Zsmalloc is better in all metrics. Moreover, z3fold apparently has latent bugs, which was made noticeable by a recent soft lockup bug report with z3fold [2]. Switching to zsmalloc not only fixed the problem, but also reduced the swap usage from 6~8G to 1~2G. Other users have also reported being bitten by mistakenly enabling z3fold. Other than hurting users, z3fold is repeatedly causing wasted engineering effort. Apart from investigating the above bug, it came up in multiple development discussions (e.g. [3]) as something we need to handle, when there aren't any legit users (at least not intentionally). The natural course of action is to deprecate z3fold, and remove in a few cycles if no objections are raised from active users. Next on the list should be zbud, as it offers marginal latency gains at the cost of huge memory waste when compared to zsmalloc. That one will need to wait until zsmalloc does not depend on MMU. Rename the user-visible config option from CONFIG_Z3FOLD to CONFIG_Z3FOLD_DEPRECATED so that users with CONFIG_Z3FOLD=y get a new prompt with explanation during make oldconfig. Also, remove CONFIG_Z3FOLD=y from defconfigs. [1]https://lore.kernel.org/lkml/CAJD7tkbRF6od-2x_L8-A1QL3=2Ww13sCj4S3i4bNndq… [2]https://lore.kernel.org/lkml/EF0ABD3E-A239-4111-A8AB-5C442E759CF3@gmail.c… [3]https://lore.kernel.org/lkml/CAJD7tkbnmeVugfunffSovJf9FAgy9rhBVt_tx=nxUve… [arnd(a)arndb.de: deprecate ZSWAP_ZPOOL_DEFAULT_Z3FOLD as well] Link: https://lkml.kernel.org/r/20240909202625.1054880-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20240904233343.933462-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed(a)google.com> Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> Acked-by: Chris Down <chris(a)chrisdown.name> Acked-by: Nhat Pham <nphamcs(a)gmail.com> Acked-by: Johannes Weiner <hannes(a)cmpxchg.org> Acked-by: Vitaly Wool <vitaly.wool(a)konsulko.com> Acked-by: Christoph Hellwig <hch(a)lst.de> Cc: Aneesh Kumar K.V <aneesh.kumar(a)kernel.org> Cc: Christophe Leroy <christophe.leroy(a)csgroup.eu> Cc: Huacai Chen <chenhuacai(a)kernel.org> Cc: Miaohe Lin <linmiaohe(a)huawei.com> Cc: Michael Ellerman <mpe(a)ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao(a)linux.ibm.com> Cc: Nicholas Piggin <npiggin(a)gmail.com> Cc: Sergey Senozhatsky <senozhatsky(a)chromium.org> Cc: WANG Xuerui <kernel(a)xen0n.name> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig index b4252c357c8e..75b366407a60 100644 --- a/arch/loongarch/configs/loongson3_defconfig +++ b/arch/loongarch/configs/loongson3_defconfig @@ -96,7 +96,6 @@ CONFIG_ZPOOL=y CONFIG_ZSWAP=y CONFIG_ZSWAP_COMPRESSOR_DEFAULT_ZSTD=y CONFIG_ZBUD=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=m # CONFIG_COMPAT_BRK is not set CONFIG_MEMORY_HOTPLUG=y diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig index 544a65fda77b..d39284489aa2 100644 --- a/arch/powerpc/configs/ppc64_defconfig +++ b/arch/powerpc/configs/ppc64_defconfig @@ -81,7 +81,6 @@ CONFIG_MODULE_SIG_SHA512=y CONFIG_PARTITION_ADVANCED=y CONFIG_BINFMT_MISC=m CONFIG_ZSWAP=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=y # CONFIG_SLAB_MERGE_DEFAULT is not set CONFIG_SLAB_FREELIST_RANDOM=y diff --git a/mm/Kconfig b/mm/Kconfig index 1aa282e35dc7..09aebca1cae3 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -146,12 +146,15 @@ config ZSWAP_ZPOOL_DEFAULT_ZBUD help Use the zbud allocator as the default allocator. -config ZSWAP_ZPOOL_DEFAULT_Z3FOLD - bool "z3fold" - select Z3FOLD +config ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED + bool "z3foldi (DEPRECATED)" + select Z3FOLD_DEPRECATED help Use the z3fold allocator as the default allocator. + Deprecated and scheduled for removal in a few cycles, + see CONFIG_Z3FOLD_DEPRECATED. + config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC bool "zsmalloc" select ZSMALLOC @@ -163,7 +166,7 @@ config ZSWAP_ZPOOL_DEFAULT string depends on ZSWAP default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD - default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD + default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC default "" @@ -177,15 +180,25 @@ config ZBUD deterministic reclaim properties that make it preferable to a higher density approach when reclaim will be used. -config Z3FOLD - tristate "3:1 compression allocator (z3fold)" +config Z3FOLD_DEPRECATED + tristate "3:1 compression allocator (z3fold) (DEPRECATED)" depends on ZSWAP help + Deprecated and scheduled for removal in a few cycles. If you have + a good reason for using Z3FOLD over ZSMALLOC, please contact + linux-mm(a)kvack.org and the zswap maintainers. + A special purpose allocator for storing compressed pages. It is designed to store up to three compressed pages per physical page. It is a ZBUD derivative so the simplicity and determinism are still there. +config Z3FOLD + tristate + default y if Z3FOLD_DEPRECATED=y + default m if Z3FOLD_DEPRECATED=m + depends on Z3FOLD_DEPRECATED + config ZSMALLOC tristate prompt "N:1 compression allocator (zsmalloc)" if (ZSWAP || ZRAM)

8 months, 4 weeks

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FAILED: patch "[PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 7a2369b74abf76cd3e54c45b30f6addb497f831b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100710-snout-expiring-3cbb@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: 7a2369b74abf ("mm: z3fold: deprecate CONFIG_Z3FOLD") 04cb7502a5d7 ("zsmalloc: use all available 24 bits of page_type") 43d746dc49bb ("mm/zsmalloc: use a proper page type") 8db00ad56461 ("mm: allow reuse of the lower 16 bit of the page type with an actual type") 6d21dde7adc0 ("mm: update _mapcount and page_type documentation") ff202303c398 ("mm: convert page type macros to enum") 46df8e73a4a3 ("mm: free up PG_slab") d99e3140a4d3 ("mm: turn folio_test_hugetlb into a PageType") fd1a745ce03e ("mm: support page_mapcount() on page_has_type() pages") 29cfe7556bfd ("mm: constify more page/folio tests") 443cbaf9e2fd ("crash: split vmcoreinfo exporting code out from crash_core.c") 85fcde402db1 ("kexec: split crashkernel reservation code out from crash_core.c") 55c49fee57af ("mm/vmalloc: remove vmap_area_list") d093602919ad ("mm: vmalloc: remove global vmap_area_root rb-tree") 7fa8cee00316 ("mm: vmalloc: move vmap_init_free_space() down in vmalloc.c") 4a693ce65b18 ("kdump: defer the insertion of crashkernel resources") 9f2a63523582 ("Merge tag 'mm-nonmm-stable-2024-01-09-10-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7a2369b74abf76cd3e54c45b30f6addb497f831b Mon Sep 17 00:00:00 2001 From: Yosry Ahmed <yosryahmed(a)google.com> Date: Wed, 4 Sep 2024 23:33:43 +0000 Subject: [PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD The z3fold compressed pages allocator is rarely used, most users use zsmalloc. The only disadvantage of zsmalloc in comparison is the dependency on MMU, and zbud is a more common option for !MMU as it was the default zswap allocator for a long time. Historically, zsmalloc had worse latency than zbud and z3fold but offered better memory savings. This is no longer the case as shown by a simple recent analysis [1]. That analysis showed that z3fold does not have any advantage over zsmalloc or zbud considering both performance and memory usage. In a kernel build test on tmpfs in a limited cgroup, z3fold took 3% more time and used 1.8% more memory. The latency of zswap_load() was 7% higher, and that of zswap_store() was 10% higher. Zsmalloc is better in all metrics. Moreover, z3fold apparently has latent bugs, which was made noticeable by a recent soft lockup bug report with z3fold [2]. Switching to zsmalloc not only fixed the problem, but also reduced the swap usage from 6~8G to 1~2G. Other users have also reported being bitten by mistakenly enabling z3fold. Other than hurting users, z3fold is repeatedly causing wasted engineering effort. Apart from investigating the above bug, it came up in multiple development discussions (e.g. [3]) as something we need to handle, when there aren't any legit users (at least not intentionally). The natural course of action is to deprecate z3fold, and remove in a few cycles if no objections are raised from active users. Next on the list should be zbud, as it offers marginal latency gains at the cost of huge memory waste when compared to zsmalloc. That one will need to wait until zsmalloc does not depend on MMU. Rename the user-visible config option from CONFIG_Z3FOLD to CONFIG_Z3FOLD_DEPRECATED so that users with CONFIG_Z3FOLD=y get a new prompt with explanation during make oldconfig. Also, remove CONFIG_Z3FOLD=y from defconfigs. [1]https://lore.kernel.org/lkml/CAJD7tkbRF6od-2x_L8-A1QL3=2Ww13sCj4S3i4bNndq… [2]https://lore.kernel.org/lkml/EF0ABD3E-A239-4111-A8AB-5C442E759CF3@gmail.c… [3]https://lore.kernel.org/lkml/CAJD7tkbnmeVugfunffSovJf9FAgy9rhBVt_tx=nxUve… [arnd(a)arndb.de: deprecate ZSWAP_ZPOOL_DEFAULT_Z3FOLD as well] Link: https://lkml.kernel.org/r/20240909202625.1054880-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20240904233343.933462-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed(a)google.com> Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> Acked-by: Chris Down <chris(a)chrisdown.name> Acked-by: Nhat Pham <nphamcs(a)gmail.com> Acked-by: Johannes Weiner <hannes(a)cmpxchg.org> Acked-by: Vitaly Wool <vitaly.wool(a)konsulko.com> Acked-by: Christoph Hellwig <hch(a)lst.de> Cc: Aneesh Kumar K.V <aneesh.kumar(a)kernel.org> Cc: Christophe Leroy <christophe.leroy(a)csgroup.eu> Cc: Huacai Chen <chenhuacai(a)kernel.org> Cc: Miaohe Lin <linmiaohe(a)huawei.com> Cc: Michael Ellerman <mpe(a)ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao(a)linux.ibm.com> Cc: Nicholas Piggin <npiggin(a)gmail.com> Cc: Sergey Senozhatsky <senozhatsky(a)chromium.org> Cc: WANG Xuerui <kernel(a)xen0n.name> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig index b4252c357c8e..75b366407a60 100644 --- a/arch/loongarch/configs/loongson3_defconfig +++ b/arch/loongarch/configs/loongson3_defconfig @@ -96,7 +96,6 @@ CONFIG_ZPOOL=y CONFIG_ZSWAP=y CONFIG_ZSWAP_COMPRESSOR_DEFAULT_ZSTD=y CONFIG_ZBUD=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=m # CONFIG_COMPAT_BRK is not set CONFIG_MEMORY_HOTPLUG=y diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig index 544a65fda77b..d39284489aa2 100644 --- a/arch/powerpc/configs/ppc64_defconfig +++ b/arch/powerpc/configs/ppc64_defconfig @@ -81,7 +81,6 @@ CONFIG_MODULE_SIG_SHA512=y CONFIG_PARTITION_ADVANCED=y CONFIG_BINFMT_MISC=m CONFIG_ZSWAP=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=y # CONFIG_SLAB_MERGE_DEFAULT is not set CONFIG_SLAB_FREELIST_RANDOM=y diff --git a/mm/Kconfig b/mm/Kconfig index 1aa282e35dc7..09aebca1cae3 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -146,12 +146,15 @@ config ZSWAP_ZPOOL_DEFAULT_ZBUD help Use the zbud allocator as the default allocator. -config ZSWAP_ZPOOL_DEFAULT_Z3FOLD - bool "z3fold" - select Z3FOLD +config ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED + bool "z3foldi (DEPRECATED)" + select Z3FOLD_DEPRECATED help Use the z3fold allocator as the default allocator. + Deprecated and scheduled for removal in a few cycles, + see CONFIG_Z3FOLD_DEPRECATED. + config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC bool "zsmalloc" select ZSMALLOC @@ -163,7 +166,7 @@ config ZSWAP_ZPOOL_DEFAULT string depends on ZSWAP default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD - default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD + default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC default "" @@ -177,15 +180,25 @@ config ZBUD deterministic reclaim properties that make it preferable to a higher density approach when reclaim will be used. -config Z3FOLD - tristate "3:1 compression allocator (z3fold)" +config Z3FOLD_DEPRECATED + tristate "3:1 compression allocator (z3fold) (DEPRECATED)" depends on ZSWAP help + Deprecated and scheduled for removal in a few cycles. If you have + a good reason for using Z3FOLD over ZSMALLOC, please contact + linux-mm(a)kvack.org and the zswap maintainers. + A special purpose allocator for storing compressed pages. It is designed to store up to three compressed pages per physical page. It is a ZBUD derivative so the simplicity and determinism are still there. +config Z3FOLD + tristate + default y if Z3FOLD_DEPRECATED=y + default m if Z3FOLD_DEPRECATED=m + depends on Z3FOLD_DEPRECATED + config ZSMALLOC tristate prompt "N:1 compression allocator (zsmalloc)" if (ZSWAP || ZRAM)

8 months, 4 weeks

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0
0 0

FAILED: patch "[PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD" failed to apply to 6.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.10.y git checkout FETCH_HEAD git cherry-pick -x 7a2369b74abf76cd3e54c45b30f6addb497f831b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024100708-flatware-expert-550d@gregkh' --subject-prefix 'PATCH 6.10.y' HEAD^.. Possible dependencies: 7a2369b74abf ("mm: z3fold: deprecate CONFIG_Z3FOLD") 04cb7502a5d7 ("zsmalloc: use all available 24 bits of page_type") 43d746dc49bb ("mm/zsmalloc: use a proper page type") 8db00ad56461 ("mm: allow reuse of the lower 16 bit of the page type with an actual type") 6d21dde7adc0 ("mm: update _mapcount and page_type documentation") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7a2369b74abf76cd3e54c45b30f6addb497f831b Mon Sep 17 00:00:00 2001 From: Yosry Ahmed <yosryahmed(a)google.com> Date: Wed, 4 Sep 2024 23:33:43 +0000 Subject: [PATCH] mm: z3fold: deprecate CONFIG_Z3FOLD The z3fold compressed pages allocator is rarely used, most users use zsmalloc. The only disadvantage of zsmalloc in comparison is the dependency on MMU, and zbud is a more common option for !MMU as it was the default zswap allocator for a long time. Historically, zsmalloc had worse latency than zbud and z3fold but offered better memory savings. This is no longer the case as shown by a simple recent analysis [1]. That analysis showed that z3fold does not have any advantage over zsmalloc or zbud considering both performance and memory usage. In a kernel build test on tmpfs in a limited cgroup, z3fold took 3% more time and used 1.8% more memory. The latency of zswap_load() was 7% higher, and that of zswap_store() was 10% higher. Zsmalloc is better in all metrics. Moreover, z3fold apparently has latent bugs, which was made noticeable by a recent soft lockup bug report with z3fold [2]. Switching to zsmalloc not only fixed the problem, but also reduced the swap usage from 6~8G to 1~2G. Other users have also reported being bitten by mistakenly enabling z3fold. Other than hurting users, z3fold is repeatedly causing wasted engineering effort. Apart from investigating the above bug, it came up in multiple development discussions (e.g. [3]) as something we need to handle, when there aren't any legit users (at least not intentionally). The natural course of action is to deprecate z3fold, and remove in a few cycles if no objections are raised from active users. Next on the list should be zbud, as it offers marginal latency gains at the cost of huge memory waste when compared to zsmalloc. That one will need to wait until zsmalloc does not depend on MMU. Rename the user-visible config option from CONFIG_Z3FOLD to CONFIG_Z3FOLD_DEPRECATED so that users with CONFIG_Z3FOLD=y get a new prompt with explanation during make oldconfig. Also, remove CONFIG_Z3FOLD=y from defconfigs. [1]https://lore.kernel.org/lkml/CAJD7tkbRF6od-2x_L8-A1QL3=2Ww13sCj4S3i4bNndq… [2]https://lore.kernel.org/lkml/EF0ABD3E-A239-4111-A8AB-5C442E759CF3@gmail.c… [3]https://lore.kernel.org/lkml/CAJD7tkbnmeVugfunffSovJf9FAgy9rhBVt_tx=nxUve… [arnd(a)arndb.de: deprecate ZSWAP_ZPOOL_DEFAULT_Z3FOLD as well] Link: https://lkml.kernel.org/r/20240909202625.1054880-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20240904233343.933462-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed(a)google.com> Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> Acked-by: Chris Down <chris(a)chrisdown.name> Acked-by: Nhat Pham <nphamcs(a)gmail.com> Acked-by: Johannes Weiner <hannes(a)cmpxchg.org> Acked-by: Vitaly Wool <vitaly.wool(a)konsulko.com> Acked-by: Christoph Hellwig <hch(a)lst.de> Cc: Aneesh Kumar K.V <aneesh.kumar(a)kernel.org> Cc: Christophe Leroy <christophe.leroy(a)csgroup.eu> Cc: Huacai Chen <chenhuacai(a)kernel.org> Cc: Miaohe Lin <linmiaohe(a)huawei.com> Cc: Michael Ellerman <mpe(a)ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao(a)linux.ibm.com> Cc: Nicholas Piggin <npiggin(a)gmail.com> Cc: Sergey Senozhatsky <senozhatsky(a)chromium.org> Cc: WANG Xuerui <kernel(a)xen0n.name> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig index b4252c357c8e..75b366407a60 100644 --- a/arch/loongarch/configs/loongson3_defconfig +++ b/arch/loongarch/configs/loongson3_defconfig @@ -96,7 +96,6 @@ CONFIG_ZPOOL=y CONFIG_ZSWAP=y CONFIG_ZSWAP_COMPRESSOR_DEFAULT_ZSTD=y CONFIG_ZBUD=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=m # CONFIG_COMPAT_BRK is not set CONFIG_MEMORY_HOTPLUG=y diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig index 544a65fda77b..d39284489aa2 100644 --- a/arch/powerpc/configs/ppc64_defconfig +++ b/arch/powerpc/configs/ppc64_defconfig @@ -81,7 +81,6 @@ CONFIG_MODULE_SIG_SHA512=y CONFIG_PARTITION_ADVANCED=y CONFIG_BINFMT_MISC=m CONFIG_ZSWAP=y -CONFIG_Z3FOLD=y CONFIG_ZSMALLOC=y # CONFIG_SLAB_MERGE_DEFAULT is not set CONFIG_SLAB_FREELIST_RANDOM=y diff --git a/mm/Kconfig b/mm/Kconfig index 1aa282e35dc7..09aebca1cae3 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -146,12 +146,15 @@ config ZSWAP_ZPOOL_DEFAULT_ZBUD help Use the zbud allocator as the default allocator. -config ZSWAP_ZPOOL_DEFAULT_Z3FOLD - bool "z3fold" - select Z3FOLD +config ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED + bool "z3foldi (DEPRECATED)" + select Z3FOLD_DEPRECATED help Use the z3fold allocator as the default allocator. + Deprecated and scheduled for removal in a few cycles, + see CONFIG_Z3FOLD_DEPRECATED. + config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC bool "zsmalloc" select ZSMALLOC @@ -163,7 +166,7 @@ config ZSWAP_ZPOOL_DEFAULT string depends on ZSWAP default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD - default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD + default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD_DEPRECATED default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC default "" @@ -177,15 +180,25 @@ config ZBUD deterministic reclaim properties that make it preferable to a higher density approach when reclaim will be used. -config Z3FOLD - tristate "3:1 compression allocator (z3fold)" +config Z3FOLD_DEPRECATED + tristate "3:1 compression allocator (z3fold) (DEPRECATED)" depends on ZSWAP help + Deprecated and scheduled for removal in a few cycles. If you have + a good reason for using Z3FOLD over ZSMALLOC, please contact + linux-mm(a)kvack.org and the zswap maintainers. + A special purpose allocator for storing compressed pages. It is designed to store up to three compressed pages per physical page. It is a ZBUD derivative so the simplicity and determinism are still there. +config Z3FOLD + tristate + default y if Z3FOLD_DEPRECATED=y + default m if Z3FOLD_DEPRECATED=m + depends on Z3FOLD_DEPRECATED + config ZSMALLOC tristate prompt "N:1 compression allocator (zsmalloc)" if (ZSWAP || ZRAM)

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