November 2024 - Linux-stable-mirror

FAILED: Patch "mm: shmem: fix data-race in shmem_getattr()" failed to apply to v6.1-stable tree

by Sasha Levin

The patch below does not apply to the v6.1-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>. Thanks, Sasha ------------------ original commit in Linus's tree ------------------ From d949d1d14fa281ace388b1de978e8f2cd52875cf Mon Sep 17 00:00:00 2001 From: Jeongjun Park <aha310510(a)gmail.com> Date: Mon, 9 Sep 2024 21:35:58 +0900 Subject: [PATCH] mm: shmem: fix data-race in shmem_getattr() I got the following KCSAN report during syzbot testing: ================================================================== BUG: KCSAN: data-race in generic_fillattr / inode_set_ctime_current write to 0xffff888102eb3260 of 4 bytes by task 6565 on cpu 1: inode_set_ctime_to_ts include/linux/fs.h:1638 [inline] inode_set_ctime_current+0x169/0x1d0 fs/inode.c:2626 shmem_mknod+0x117/0x180 mm/shmem.c:3443 shmem_create+0x34/0x40 mm/shmem.c:3497 lookup_open fs/namei.c:3578 [inline] open_last_lookups fs/namei.c:3647 [inline] path_openat+0xdbc/0x1f00 fs/namei.c:3883 do_filp_open+0xf7/0x200 fs/namei.c:3913 do_sys_openat2+0xab/0x120 fs/open.c:1416 do_sys_open fs/open.c:1431 [inline] __do_sys_openat fs/open.c:1447 [inline] __se_sys_openat fs/open.c:1442 [inline] __x64_sys_openat+0xf3/0x120 fs/open.c:1442 x64_sys_call+0x1025/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x54/0x120 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e read to 0xffff888102eb3260 of 4 bytes by task 3498 on cpu 0: inode_get_ctime_nsec include/linux/fs.h:1623 [inline] inode_get_ctime include/linux/fs.h:1629 [inline] generic_fillattr+0x1dd/0x2f0 fs/stat.c:62 shmem_getattr+0x17b/0x200 mm/shmem.c:1157 vfs_getattr_nosec fs/stat.c:166 [inline] vfs_getattr+0x19b/0x1e0 fs/stat.c:207 vfs_statx_path fs/stat.c:251 [inline] vfs_statx+0x134/0x2f0 fs/stat.c:315 vfs_fstatat+0xec/0x110 fs/stat.c:341 __do_sys_newfstatat fs/stat.c:505 [inline] __se_sys_newfstatat+0x58/0x260 fs/stat.c:499 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:499 x64_sys_call+0x141f/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:263 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x54/0x120 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e value changed: 0x2755ae53 -> 0x27ee44d3 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 3498 Comm: udevd Not tainted 6.11.0-rc6-syzkaller-00326-gd1f2d51b711a-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 ================================================================== When calling generic_fillattr(), if you don't hold read lock, data-race will occur in inode member variables, which can cause unexpected behavior. Since there is no special protection when shmem_getattr() calls generic_fillattr(), data-race occurs by functions such as shmem_unlink() or shmem_mknod(). This can cause unexpected results, so commenting it out is not enough. Therefore, when calling generic_fillattr() from shmem_getattr(), it is appropriate to protect the inode using inode_lock_shared() and inode_unlock_shared() to prevent data-race. Link: https://lkml.kernel.org/r/20240909123558.70229-1-aha310510@gmail.com Fixes: 44a30220bc0a ("shmem: recalculate file inode when fstat") Signed-off-by: Jeongjun Park <aha310510(a)gmail.com> Reported-by: syzbot <syzkaller(a)googlegroup.com> Cc: Hugh Dickins <hughd(a)google.com> Cc: Yu Zhao <yuzhao(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/shmem.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/shmem.c b/mm/shmem.c index c5adb987b23cf..4ba1d00fabdaa 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1166,7 +1166,9 @@ static int shmem_getattr(struct mnt_idmap *idmap, stat->attributes_mask |= (STATX_ATTR_APPEND | STATX_ATTR_IMMUTABLE | STATX_ATTR_NODUMP); + inode_lock_shared(inode); generic_fillattr(idmap, request_mask, inode, stat); + inode_unlock_shared(inode); if (shmem_huge_global_enabled(inode, 0, 0, false, NULL, 0)) stat->blksize = HPAGE_PMD_SIZE; -- 2.43.0

5 months, 3 weeks

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FAILED: Patch "mm: multi-gen LRU: remove MM_LEAF_OLD and MM_NONLEAF_TOTAL stats" failed to apply to v6.1-stable tree

by Sasha Levin

The patch below does not apply to the v6.1-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>. Thanks, Sasha ------------------ original commit in Linus's tree ------------------ From ddd6d8e975b171ea3f63a011a75820883ff0d479 Mon Sep 17 00:00:00 2001 From: Yu Zhao <yuzhao(a)google.com> Date: Sat, 19 Oct 2024 01:29:38 +0000 Subject: [PATCH] mm: multi-gen LRU: remove MM_LEAF_OLD and MM_NONLEAF_TOTAL stats Patch series "mm: multi-gen LRU: Have secondary MMUs participate in MM_WALK". Today, the MM_WALK capability causes MGLRU to clear the young bit from PMDs and PTEs during the page table walk before eviction, but MGLRU does not call the clear_young() MMU notifier in this case. By not calling this notifier, the MM walk takes less time/CPU, but it causes pages that are accessed mostly through KVM / secondary MMUs to appear younger than they should be. We do call the clear_young() notifier today, but only when attempting to evict the page, so we end up clearing young/accessed information less frequently for secondary MMUs than for mm PTEs, and therefore they appear younger and are less likely to be evicted. Therefore, memory that is *not* being accessed mostly by KVM will be evicted *more* frequently, worsening performance. ChromeOS observed a tab-open latency regression when enabling MGLRU with a setup that involved running a VM: Tab-open latency histogram (ms) Version p50 mean p95 p99 max base 1315 1198 2347 3454 10319 mglru 2559 1311 7399 12060 43758 fix 1119 926 2470 4211 6947 This series replaces the final non-selftest patchs from this series[1], which introduced a similar change (and a new MMU notifier) with KVM optimizations. I'll send a separate series (to Sean and Paolo) for the KVM optimizations. This series also makes proactive reclaim with MGLRU possible for KVM memory. I have verified that this functions correctly with the selftest from [1], but given that that test is a KVM selftest, I'll send it with the rest of the KVM optimizations later. Andrew, let me know if you'd like to take the test now anyway. [1]: https://lore.kernel.org/linux-mm/20240926013506.860253-18-jthoughton@google… This patch (of 2): The removed stats, MM_LEAF_OLD and MM_NONLEAF_TOTAL, are not very helpful and become more complicated to properly compute when adding test/clear_young() notifiers in MGLRU's mm walk. Link: https://lkml.kernel.org/r/20241019012940.3656292-1-jthoughton@google.com Link: https://lkml.kernel.org/r/20241019012940.3656292-2-jthoughton@google.com Fixes: bd74fdaea146 ("mm: multi-gen LRU: support page table walks") Signed-off-by: Yu Zhao <yuzhao(a)google.com> Signed-off-by: James Houghton <jthoughton(a)google.com> Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: David Matlack <dmatlack(a)google.com> Cc: David Rientjes <rientjes(a)google.com> Cc: David Stevens <stevensd(a)google.com> Cc: Oliver Upton <oliver.upton(a)linux.dev> Cc: Paolo Bonzini <pbonzini(a)redhat.com> Cc: Sean Christopherson <seanjc(a)google.com> Cc: Wei Xu <weixugc(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/mmzone.h | 2 -- mm/vmscan.c | 14 +++++--------- 2 files changed, 5 insertions(+), 11 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 17506e4a28355..9342e5692dab6 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -458,9 +458,7 @@ struct lru_gen_folio { enum { MM_LEAF_TOTAL, /* total leaf entries */ - MM_LEAF_OLD, /* old leaf entries */ MM_LEAF_YOUNG, /* young leaf entries */ - MM_NONLEAF_TOTAL, /* total non-leaf entries */ MM_NONLEAF_FOUND, /* non-leaf entries found in Bloom filters */ MM_NONLEAF_ADDED, /* non-leaf entries added to Bloom filters */ NR_MM_STATS diff --git a/mm/vmscan.c b/mm/vmscan.c index eb4e8440c5071..4f1d33e4b3601 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3399,7 +3399,6 @@ static bool walk_pte_range(pmd_t *pmd, unsigned long start, unsigned long end, continue; if (!pte_young(ptent)) { - walk->mm_stats[MM_LEAF_OLD]++; continue; } @@ -3552,7 +3551,6 @@ static void walk_pmd_range(pud_t *pud, unsigned long start, unsigned long end, walk->mm_stats[MM_LEAF_TOTAL]++; if (!pmd_young(val)) { - walk->mm_stats[MM_LEAF_OLD]++; continue; } @@ -3564,8 +3562,6 @@ static void walk_pmd_range(pud_t *pud, unsigned long start, unsigned long end, continue; } - walk->mm_stats[MM_NONLEAF_TOTAL]++; - if (!walk->force_scan && should_clear_pmd_young()) { if (!pmd_young(val)) continue; @@ -5254,11 +5250,11 @@ static void lru_gen_seq_show_full(struct seq_file *m, struct lruvec *lruvec, for (tier = 0; tier < MAX_NR_TIERS; tier++) { seq_printf(m, " %10d", tier); for (type = 0; type < ANON_AND_FILE; type++) { - const char *s = " "; + const char *s = "xxx"; unsigned long n[3] = {}; if (seq == max_seq) { - s = "RT "; + s = "RTx"; n[0] = READ_ONCE(lrugen->avg_refaulted[type][tier]); n[1] = READ_ONCE(lrugen->avg_total[type][tier]); } else if (seq == min_seq[type] || NR_HIST_GENS > 1) { @@ -5280,14 +5276,14 @@ static void lru_gen_seq_show_full(struct seq_file *m, struct lruvec *lruvec, seq_puts(m, " "); for (i = 0; i < NR_MM_STATS; i++) { - const char *s = " "; + const char *s = "xxxx"; unsigned long n = 0; if (seq == max_seq && NR_HIST_GENS == 1) { - s = "LOYNFA"; + s = "TYFA"; n = READ_ONCE(mm_state->stats[hist][i]); } else if (seq != max_seq && NR_HIST_GENS > 1) { - s = "loynfa"; + s = "tyfa"; n = READ_ONCE(mm_state->stats[hist][i]); } -- 2.43.0

5 months, 3 weeks

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FAILED: Patch "Revert "drm/amd/display: update DML2 policy EnhancedPrefetchScheduleAccelerationFinal DCN35"" failed to apply to v6.6-stable tree

by Sasha Levin

The patch below does not apply to the v6.6-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>. Thanks, Sasha ------------------ original commit in Linus's tree ------------------ From 1b6063a57754eae5705753c01e78dc268b989038 Mon Sep 17 00:00:00 2001 From: Ovidiu Bunea <Ovidiu.Bunea(a)amd.com> Date: Fri, 11 Oct 2024 11:12:19 -0400 Subject: [PATCH] Revert "drm/amd/display: update DML2 policy EnhancedPrefetchScheduleAccelerationFinal DCN35" This reverts commit 9dad21f910fc ("drm/amd/display: update DML2 policy EnhancedPrefetchScheduleAccelerationFinal DCN35") [why & how] The offending commit exposes a hang with lid close/open behavior. Both issues seem to be related to ODM 2:1 mode switching, so there is another issue generic to that sequence that needs to be investigated. Cc: Mario Limonciello <mario.limonciello(a)amd.com> Cc: Alex Deucher <alexander.deucher(a)amd.com> Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas(a)amd.com> Signed-off-by: Ovidiu Bunea <Ovidiu.Bunea(a)amd.com> Signed-off-by: Tom Chung <chiahsuan.chung(a)amd.com> Tested-by: Daniel Wheeler <daniel.wheeler(a)amd.com> Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com> (cherry picked from commit 68bf95317ebf2cfa7105251e4279e951daceefb7) Cc: stable(a)vger.kernel.org --- drivers/gpu/drm/amd/display/dc/dml2/dml2_policy.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml2_policy.c b/drivers/gpu/drm/amd/display/dc/dml2/dml2_policy.c index 11c904ae29586..c4c52173ef224 100644 --- a/drivers/gpu/drm/amd/display/dc/dml2/dml2_policy.c +++ b/drivers/gpu/drm/amd/display/dc/dml2/dml2_policy.c @@ -303,6 +303,7 @@ void build_unoptimized_policy_settings(enum dml_project_id project, struct dml_m if (project == dml_project_dcn35 || project == dml_project_dcn351) { policy->DCCProgrammingAssumesScanDirectionUnknownFinal = false; + policy->EnhancedPrefetchScheduleAccelerationFinal = 0; policy->AllowForPStateChangeOrStutterInVBlankFinal = dml_prefetch_support_uclk_fclk_and_stutter_if_possible; /*new*/ policy->UseOnlyMaxPrefetchModes = 1; } -- 2.43.0

5 months, 3 weeks

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FAILED: Patch "mm: multi-gen LRU: use {ptep,pmdp}_clear_young_notify()" failed to apply to v6.6-stable tree

by Sasha Levin

The patch below does not apply to the v6.6-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>. Thanks, Sasha ------------------ original commit in Linus's tree ------------------ From 1d4832becdc2cdb2cffe2a6050c9d9fd8ff1c58c Mon Sep 17 00:00:00 2001 From: Yu Zhao <yuzhao(a)google.com> Date: Sat, 19 Oct 2024 01:29:39 +0000 Subject: [PATCH] mm: multi-gen LRU: use {ptep,pmdp}_clear_young_notify() When the MM_WALK capability is enabled, memory that is mostly accessed by a VM appears younger than it really is, therefore this memory will be less likely to be evicted. Therefore, the presence of a running VM can significantly increase swap-outs for non-VM memory, regressing the performance for the rest of the system. Fix this regression by always calling {ptep,pmdp}_clear_young_notify() whenever we clear the young bits on PMDs/PTEs. [jthoughton(a)google.com: fix link-time error] Link: https://lkml.kernel.org/r/20241019012940.3656292-3-jthoughton@google.com Fixes: bd74fdaea146 ("mm: multi-gen LRU: support page table walks") Signed-off-by: Yu Zhao <yuzhao(a)google.com> Signed-off-by: James Houghton <jthoughton(a)google.com> Reported-by: David Stevens <stevensd(a)google.com> Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: David Matlack <dmatlack(a)google.com> Cc: David Rientjes <rientjes(a)google.com> Cc: Oliver Upton <oliver.upton(a)linux.dev> Cc: Paolo Bonzini <pbonzini(a)redhat.com> Cc: Sean Christopherson <seanjc(a)google.com> Cc: Wei Xu <weixugc(a)google.com> Cc: <stable(a)vger.kernel.org> Cc: kernel test robot <lkp(a)intel.com> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/mmzone.h | 5 ++- mm/rmap.c | 9 ++--- mm/vmscan.c | 88 +++++++++++++++++++++++------------------- 3 files changed, 55 insertions(+), 47 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 9342e5692dab6..5b1c984daf454 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -555,7 +555,7 @@ struct lru_gen_memcg { void lru_gen_init_pgdat(struct pglist_data *pgdat); void lru_gen_init_lruvec(struct lruvec *lruvec); -void lru_gen_look_around(struct page_vma_mapped_walk *pvmw); +bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw); void lru_gen_init_memcg(struct mem_cgroup *memcg); void lru_gen_exit_memcg(struct mem_cgroup *memcg); @@ -574,8 +574,9 @@ static inline void lru_gen_init_lruvec(struct lruvec *lruvec) { } -static inline void lru_gen_look_around(struct page_vma_mapped_walk *pvmw) +static inline bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw) { + return false; } static inline void lru_gen_init_memcg(struct mem_cgroup *memcg) diff --git a/mm/rmap.c b/mm/rmap.c index a8797d1b3d496..73d5998677d40 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -885,13 +885,10 @@ static bool folio_referenced_one(struct folio *folio, return false; } - if (pvmw.pte) { - if (lru_gen_enabled() && - pte_young(ptep_get(pvmw.pte))) { - lru_gen_look_around(&pvmw); + if (lru_gen_enabled() && pvmw.pte) { + if (lru_gen_look_around(&pvmw)) referenced++; - } - + } else if (pvmw.pte) { if (ptep_clear_flush_young_notify(vma, address, pvmw.pte)) referenced++; diff --git a/mm/vmscan.c b/mm/vmscan.c index 4f1d33e4b3601..ddaaff67642e1 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -56,6 +56,7 @@ #include <linux/khugepaged.h> #include <linux/rculist_nulls.h> #include <linux/random.h> +#include <linux/mmu_notifier.h> #include <asm/tlbflush.h> #include <asm/div64.h> @@ -3294,7 +3295,8 @@ static bool get_next_vma(unsigned long mask, unsigned long size, struct mm_walk return false; } -static unsigned long get_pte_pfn(pte_t pte, struct vm_area_struct *vma, unsigned long addr) +static unsigned long get_pte_pfn(pte_t pte, struct vm_area_struct *vma, unsigned long addr, + struct pglist_data *pgdat) { unsigned long pfn = pte_pfn(pte); @@ -3306,13 +3308,20 @@ static unsigned long get_pte_pfn(pte_t pte, struct vm_area_struct *vma, unsigned if (WARN_ON_ONCE(pte_devmap(pte) || pte_special(pte))) return -1; + if (!pte_young(pte) && !mm_has_notifiers(vma->vm_mm)) + return -1; + if (WARN_ON_ONCE(!pfn_valid(pfn))) return -1; + if (pfn < pgdat->node_start_pfn || pfn >= pgdat_end_pfn(pgdat)) + return -1; + return pfn; } -static unsigned long get_pmd_pfn(pmd_t pmd, struct vm_area_struct *vma, unsigned long addr) +static unsigned long get_pmd_pfn(pmd_t pmd, struct vm_area_struct *vma, unsigned long addr, + struct pglist_data *pgdat) { unsigned long pfn = pmd_pfn(pmd); @@ -3324,9 +3333,15 @@ static unsigned long get_pmd_pfn(pmd_t pmd, struct vm_area_struct *vma, unsigned if (WARN_ON_ONCE(pmd_devmap(pmd))) return -1; + if (!pmd_young(pmd) && !mm_has_notifiers(vma->vm_mm)) + return -1; + if (WARN_ON_ONCE(!pfn_valid(pfn))) return -1; + if (pfn < pgdat->node_start_pfn || pfn >= pgdat_end_pfn(pgdat)) + return -1; + return pfn; } @@ -3335,10 +3350,6 @@ static struct folio *get_pfn_folio(unsigned long pfn, struct mem_cgroup *memcg, { struct folio *folio; - /* try to avoid unnecessary memory loads */ - if (pfn < pgdat->node_start_pfn || pfn >= pgdat_end_pfn(pgdat)) - return NULL; - folio = pfn_folio(pfn); if (folio_nid(folio) != pgdat->node_id) return NULL; @@ -3394,20 +3405,16 @@ static bool walk_pte_range(pmd_t *pmd, unsigned long start, unsigned long end, total++; walk->mm_stats[MM_LEAF_TOTAL]++; - pfn = get_pte_pfn(ptent, args->vma, addr); + pfn = get_pte_pfn(ptent, args->vma, addr, pgdat); if (pfn == -1) continue; - if (!pte_young(ptent)) { - continue; - } - folio = get_pfn_folio(pfn, memcg, pgdat, walk->can_swap); if (!folio) continue; - if (!ptep_test_and_clear_young(args->vma, addr, pte + i)) - VM_WARN_ON_ONCE(true); + if (!ptep_clear_young_notify(args->vma, addr, pte + i)) + continue; young++; walk->mm_stats[MM_LEAF_YOUNG]++; @@ -3473,21 +3480,25 @@ static void walk_pmd_range_locked(pud_t *pud, unsigned long addr, struct vm_area /* don't round down the first address */ addr = i ? (*first & PMD_MASK) + i * PMD_SIZE : *first; - pfn = get_pmd_pfn(pmd[i], vma, addr); - if (pfn == -1) + if (!pmd_present(pmd[i])) goto next; if (!pmd_trans_huge(pmd[i])) { - if (!walk->force_scan && should_clear_pmd_young()) + if (!walk->force_scan && should_clear_pmd_young() && + !mm_has_notifiers(args->mm)) pmdp_test_and_clear_young(vma, addr, pmd + i); goto next; } + pfn = get_pmd_pfn(pmd[i], vma, addr, pgdat); + if (pfn == -1) + goto next; + folio = get_pfn_folio(pfn, memcg, pgdat, walk->can_swap); if (!folio) goto next; - if (!pmdp_test_and_clear_young(vma, addr, pmd + i)) + if (!pmdp_clear_young_notify(vma, addr, pmd + i)) goto next; walk->mm_stats[MM_LEAF_YOUNG]++; @@ -3545,24 +3556,18 @@ static void walk_pmd_range(pud_t *pud, unsigned long start, unsigned long end, } if (pmd_trans_huge(val)) { - unsigned long pfn = pmd_pfn(val); struct pglist_data *pgdat = lruvec_pgdat(walk->lruvec); + unsigned long pfn = get_pmd_pfn(val, vma, addr, pgdat); walk->mm_stats[MM_LEAF_TOTAL]++; - if (!pmd_young(val)) { - continue; - } - - /* try to avoid unnecessary memory loads */ - if (pfn < pgdat->node_start_pfn || pfn >= pgdat_end_pfn(pgdat)) - continue; - - walk_pmd_range_locked(pud, addr, vma, args, bitmap, &first); + if (pfn != -1) + walk_pmd_range_locked(pud, addr, vma, args, bitmap, &first); continue; } - if (!walk->force_scan && should_clear_pmd_young()) { + if (!walk->force_scan && should_clear_pmd_young() && + !mm_has_notifiers(args->mm)) { if (!pmd_young(val)) continue; @@ -4036,13 +4041,13 @@ static void lru_gen_age_node(struct pglist_data *pgdat, struct scan_control *sc) * the PTE table to the Bloom filter. This forms a feedback loop between the * eviction and the aging. */ -void lru_gen_look_around(struct page_vma_mapped_walk *pvmw) +bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw) { int i; unsigned long start; unsigned long end; struct lru_gen_mm_walk *walk; - int young = 0; + int young = 1; pte_t *pte = pvmw->pte; unsigned long addr = pvmw->address; struct vm_area_struct *vma = pvmw->vma; @@ -4058,12 +4063,15 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw) lockdep_assert_held(pvmw->ptl); VM_WARN_ON_ONCE_FOLIO(folio_test_lru(folio), folio); + if (!ptep_clear_young_notify(vma, addr, pte)) + return false; + if (spin_is_contended(pvmw->ptl)) - return; + return true; /* exclude special VMAs containing anon pages from COW */ if (vma->vm_flags & VM_SPECIAL) - return; + return true; /* avoid taking the LRU lock under the PTL when possible */ walk = current->reclaim_state ? current->reclaim_state->mm_walk : NULL; @@ -4071,6 +4079,9 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw) start = max(addr & PMD_MASK, vma->vm_start); end = min(addr | ~PMD_MASK, vma->vm_end - 1) + 1; + if (end - start == PAGE_SIZE) + return true; + if (end - start > MIN_LRU_BATCH * PAGE_SIZE) { if (addr - start < MIN_LRU_BATCH * PAGE_SIZE / 2) end = start + MIN_LRU_BATCH * PAGE_SIZE; @@ -4084,7 +4095,7 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw) /* folio_update_gen() requires stable folio_memcg() */ if (!mem_cgroup_trylock_pages(memcg)) - return; + return true; arch_enter_lazy_mmu_mode(); @@ -4094,19 +4105,16 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw) unsigned long pfn; pte_t ptent = ptep_get(pte + i); - pfn = get_pte_pfn(ptent, vma, addr); + pfn = get_pte_pfn(ptent, vma, addr, pgdat); if (pfn == -1) continue; - if (!pte_young(ptent)) - continue; - folio = get_pfn_folio(pfn, memcg, pgdat, can_swap); if (!folio) continue; - if (!ptep_test_and_clear_young(vma, addr, pte + i)) - VM_WARN_ON_ONCE(true); + if (!ptep_clear_young_notify(vma, addr, pte + i)) + continue; young++; @@ -4136,6 +4144,8 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw) /* feedback from rmap walkers to page table walkers */ if (mm_state && suitable_to_scan(i, young)) update_bloom_filter(mm_state, max_seq, pvmw->pmd); + + return true; } /****************************************************************************** -- 2.43.0

5 months, 3 weeks

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FAILED: Patch "gpiolib: fix debugfs newline separators" failed to apply to v6.6-stable tree

by Sasha Levin

The patch below does not apply to the v6.6-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>. Thanks, Sasha ------------------ original commit in Linus's tree ------------------ From 3e8b7238b427e05498034c240451af5f5495afda Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan+linaro(a)kernel.org> Date: Mon, 28 Oct 2024 13:49:58 +0100 Subject: [PATCH] gpiolib: fix debugfs newline separators The gpiolib debugfs interface exports a list of all gpio chips in a system and the state of their pins. The gpio chip sections are supposed to be separated by a newline character, but a long-standing bug prevents the separator from being included when output is generated in multiple sessions, making the output inconsistent and hard to read. Make sure to only suppress the newline separator at the beginning of the file as intended. Fixes: f9c4a31f6150 ("gpiolib: Use seq_file's iterator interface") Cc: stable(a)vger.kernel.org # 3.7 Cc: Thierry Reding <treding(a)nvidia.com> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> Link: https://lore.kernel.org/r/20241028125000.24051-2-johan+linaro@kernel.org Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski(a)linaro.org> --- drivers/gpio/gpiolib.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d5952ab7752c2..e27488a90bc97 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -4926,6 +4926,8 @@ static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) return NULL; s->private = priv; + if (*pos > 0) + priv->newline = true; priv->idx = srcu_read_lock(&gpio_devices_srcu); list_for_each_entry_srcu(gdev, &gpio_devices, list, -- 2.43.0

5 months, 3 weeks

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FAILED: Patch "drm/amd/pm: Vangogh: Fix kernel memory out of bounds write" failed to apply to v6.6-stable tree

by Sasha Levin

The patch below does not apply to the v6.6-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>. Thanks, Sasha ------------------ original commit in Linus's tree ------------------ From 4aa923a6e6406b43566ef6ac35a3d9a3197fa3e8 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Date: Fri, 25 Oct 2024 15:56:39 +0100 Subject: [PATCH] drm/amd/pm: Vangogh: Fix kernel memory out of bounds write KASAN reports that the GPU metrics table allocated in vangogh_tables_init() is not large enough for the memset done in smu_cmn_init_soft_gpu_metrics(). Condensed report follows: [ 33.861314] BUG: KASAN: slab-out-of-bounds in smu_cmn_init_soft_gpu_metrics+0x73/0x200 [amdgpu] [ 33.861799] Write of size 168 at addr ffff888129f59500 by task mangoapp/1067 ... [ 33.861808] CPU: 6 UID: 1000 PID: 1067 Comm: mangoapp Tainted: G W 6.12.0-rc4 #356 1a56f59a8b5182eeaf67eb7cb8b13594dd23b544 [ 33.861816] Tainted: [W]=WARN [ 33.861818] Hardware name: Valve Galileo/Galileo, BIOS F7G0107 12/01/2023 [ 33.861822] Call Trace: [ 33.861826] <TASK> [ 33.861829] dump_stack_lvl+0x66/0x90 [ 33.861838] print_report+0xce/0x620 [ 33.861853] kasan_report+0xda/0x110 [ 33.862794] kasan_check_range+0xfd/0x1a0 [ 33.862799] __asan_memset+0x23/0x40 [ 33.862803] smu_cmn_init_soft_gpu_metrics+0x73/0x200 [amdgpu 13b1bc364ec578808f676eba412c20eaab792779] [ 33.863306] vangogh_get_gpu_metrics_v2_4+0x123/0xad0 [amdgpu 13b1bc364ec578808f676eba412c20eaab792779] [ 33.864257] vangogh_common_get_gpu_metrics+0xb0c/0xbc0 [amdgpu 13b1bc364ec578808f676eba412c20eaab792779] [ 33.865682] amdgpu_dpm_get_gpu_metrics+0xcc/0x110 [amdgpu 13b1bc364ec578808f676eba412c20eaab792779] [ 33.866160] amdgpu_get_gpu_metrics+0x154/0x2d0 [amdgpu 13b1bc364ec578808f676eba412c20eaab792779] [ 33.867135] dev_attr_show+0x43/0xc0 [ 33.867147] sysfs_kf_seq_show+0x1f1/0x3b0 [ 33.867155] seq_read_iter+0x3f8/0x1140 [ 33.867173] vfs_read+0x76c/0xc50 [ 33.867198] ksys_read+0xfb/0x1d0 [ 33.867214] do_syscall_64+0x90/0x160 ... [ 33.867353] Allocated by task 378 on cpu 7 at 22.794876s: [ 33.867358] kasan_save_stack+0x33/0x50 [ 33.867364] kasan_save_track+0x17/0x60 [ 33.867367] __kasan_kmalloc+0x87/0x90 [ 33.867371] vangogh_init_smc_tables+0x3f9/0x840 [amdgpu] [ 33.867835] smu_sw_init+0xa32/0x1850 [amdgpu] [ 33.868299] amdgpu_device_init+0x467b/0x8d90 [amdgpu] [ 33.868733] amdgpu_driver_load_kms+0x19/0xf0 [amdgpu] [ 33.869167] amdgpu_pci_probe+0x2d6/0xcd0 [amdgpu] [ 33.869608] local_pci_probe+0xda/0x180 [ 33.869614] pci_device_probe+0x43f/0x6b0 Empirically we can confirm that the former allocates 152 bytes for the table, while the latter memsets the 168 large block. Root cause appears that when GPU metrics tables for v2_4 parts were added it was not considered to enlarge the table to fit. The fix in this patch is rather "brute force" and perhaps later should be done in a smarter way, by extracting and consolidating the part version to size logic to a common helper, instead of brute forcing the largest possible allocation. Nevertheless, for now this works and fixes the out of bounds write. v2: * Drop impossible v3_0 case. (Mario) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Fixes: 41cec40bc9ba ("drm/amd/pm: Vangogh: Add new gpu_metrics_v2_4 to acquire gpu_metrics") Cc: Mario Limonciello <mario.limonciello(a)amd.com> Cc: Evan Quan <evan.quan(a)amd.com> Cc: Wenyou Yang <WenYou.Yang(a)amd.com> Cc: Alex Deucher <alexander.deucher(a)amd.com> Reviewed-by: Mario Limonciello <mario.limonciello(a)amd.com> Link: https://lore.kernel.org/r/20241025145639.19124-1-tursulin@igalia.com Signed-off-by: Mario Limonciello <mario.limonciello(a)amd.com> Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com> (cherry picked from commit 0880f58f9609f0200483a49429af0f050d281703) Cc: stable(a)vger.kernel.org # v6.6+ --- drivers/gpu/drm/amd/pm/swsmu/smu11/vangogh_ppt.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/vangogh_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/vangogh_ppt.c index 22737b11b1bfb..1fe020f1f4dbe 100644 --- a/drivers/gpu/drm/amd/pm/swsmu/smu11/vangogh_ppt.c +++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/vangogh_ppt.c @@ -242,7 +242,9 @@ static int vangogh_tables_init(struct smu_context *smu) goto err0_out; smu_table->metrics_time = 0; - smu_table->gpu_metrics_table_size = max(sizeof(struct gpu_metrics_v2_3), sizeof(struct gpu_metrics_v2_2)); + smu_table->gpu_metrics_table_size = sizeof(struct gpu_metrics_v2_2); + smu_table->gpu_metrics_table_size = max(smu_table->gpu_metrics_table_size, sizeof(struct gpu_metrics_v2_3)); + smu_table->gpu_metrics_table_size = max(smu_table->gpu_metrics_table_size, sizeof(struct gpu_metrics_v2_4)); smu_table->gpu_metrics_table = kzalloc(smu_table->gpu_metrics_table_size, GFP_KERNEL); if (!smu_table->gpu_metrics_table) goto err1_out; -- 2.43.0

5 months, 3 weeks

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FAILED: Patch "mm: allow set/clear page_type again" failed to apply to v6.6-stable tree

by Sasha Levin

The patch below does not apply to the v6.6-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>. Thanks, Sasha ------------------ original commit in Linus's tree ------------------ From 9d08ec41a0645283d79a2e642205d488feaceacf Mon Sep 17 00:00:00 2001 From: Yu Zhao <yuzhao(a)google.com> Date: Sat, 19 Oct 2024 22:22:12 -0600 Subject: [PATCH] mm: allow set/clear page_type again Some page flags (page->flags) were converted to page types (page->page_types). A recent example is PG_hugetlb. From the exclusive writer's perspective, e.g., a thread doing __folio_set_hugetlb(), there is a difference between the page flag and type APIs: the former allows the same non-atomic operation to be repeated whereas the latter does not. For example, calling __folio_set_hugetlb() twice triggers VM_BUG_ON_FOLIO(), since the second call expects the type (PG_hugetlb) not to be set previously. Using add_hugetlb_folio() as an example, it calls __folio_set_hugetlb() in the following error-handling path. And when that happens, it triggers the aforementioned VM_BUG_ON_FOLIO(). if (folio_test_hugetlb(folio)) { rc = hugetlb_vmemmap_restore_folio(h, folio); if (rc) { spin_lock_irq(&hugetlb_lock); add_hugetlb_folio(h, folio, false); ... It is possible to make hugeTLB comply with the new requirements from the page type API. However, a straightforward fix would be to just allow the same page type to be set or cleared again inside the API, to avoid any changes to its callers. Link: https://lkml.kernel.org/r/20241020042212.296781-1-yuzhao@google.com Fixes: d99e3140a4d3 ("mm: turn folio_test_hugetlb into a PageType") Signed-off-by: Yu Zhao <yuzhao(a)google.com> Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org> Cc: Muchun Song <muchun.song(a)linux.dev> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/page-flags.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 1b3a767104878..cc839e4365c18 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -975,12 +975,16 @@ static __always_inline bool folio_test_##fname(const struct folio *folio) \ } \ static __always_inline void __folio_set_##fname(struct folio *folio) \ { \ + if (folio_test_##fname(folio)) \ + return; \ VM_BUG_ON_FOLIO(data_race(folio->page.page_type) != UINT_MAX, \ folio); \ folio->page.page_type = (unsigned int)PGTY_##lname << 24; \ } \ static __always_inline void __folio_clear_##fname(struct folio *folio) \ { \ + if (folio->page.page_type == UINT_MAX) \ + return; \ VM_BUG_ON_FOLIO(!folio_test_##fname(folio), folio); \ folio->page.page_type = UINT_MAX; \ } @@ -993,11 +997,15 @@ static __always_inline int Page##uname(const struct page *page) \ } \ static __always_inline void __SetPage##uname(struct page *page) \ { \ + if (Page##uname(page)) \ + return; \ VM_BUG_ON_PAGE(data_race(page->page_type) != UINT_MAX, page); \ page->page_type = (unsigned int)PGTY_##lname << 24; \ } \ static __always_inline void __ClearPage##uname(struct page *page) \ { \ + if (page->page_type == UINT_MAX) \ + return; \ VM_BUG_ON_PAGE(!Page##uname(page), page); \ page->page_type = UINT_MAX; \ } -- 2.43.0

5 months, 3 weeks

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FAILED: Patch "btrfs: fix defrag not merging contiguous extents due to merged extent maps" failed to apply to v6.6-stable tree

by Sasha Levin

The patch below does not apply to the v6.6-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>. Thanks, Sasha ------------------ original commit in Linus's tree ------------------ From 77b0d113eec49a7390ff1a08ca1923e89f5f86c6 Mon Sep 17 00:00:00 2001 From: Filipe Manana <fdmanana(a)suse.com> Date: Tue, 29 Oct 2024 15:18:45 +0000 Subject: [PATCH] btrfs: fix defrag not merging contiguous extents due to merged extent maps When running defrag (manual defrag) against a file that has extents that are contiguous and we already have the respective extent maps loaded and merged, we end up not defragging the range covered by those contiguous extents. This happens when we have an extent map that was the result of merging multiple extent maps for contiguous extents and the length of the merged extent map is greater than or equals to the defrag threshold length. The script below reproduces this scenario: $ cat test.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi mkfs.btrfs -f $DEV mount $DEV $MNT # Create a 256K file with 4 extents of 64K each. xfs_io -f -c "falloc 0 64K" \ -c "pwrite 0 64K" \ -c "falloc 64K 64K" \ -c "pwrite 64K 64K" \ -c "falloc 128K 64K" \ -c "pwrite 128K 64K" \ -c "falloc 192K 64K" \ -c "pwrite 192K 64K" \ $MNT/foo umount $MNT echo -n "Initial number of file extent items: " btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l mount $DEV $MNT # Read the whole file in order to load and merge extent maps. cat $MNT/foo > /dev/null btrfs filesystem defragment -t 128K $MNT/foo umount $MNT echo -n "Number of file extent items after defrag with 128K threshold: " btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l mount $DEV $MNT # Read the whole file in order to load and merge extent maps. cat $MNT/foo > /dev/null btrfs filesystem defragment -t 256K $MNT/foo umount $MNT echo -n "Number of file extent items after defrag with 256K threshold: " btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l Running it: $ ./test.sh Initial number of file extent items: 4 Number of file extent items after defrag with 128K threshold: 4 Number of file extent items after defrag with 256K threshold: 4 The 4 extents don't get merged because we have an extent map with a size of 256K that is the result of merging the individual extent maps for each of the four 64K extents and at defrag_lookup_extent() we have a value of zero for the generation threshold ('newer_than' argument) since this is a manual defrag. As a consequence we don't call defrag_get_extent() to get an extent map representing a single file extent item in the inode's subvolume tree, so we end up using the merged extent map at defrag_collect_targets() and decide not to defrag. Fix this by updating defrag_lookup_extent() to always discard extent maps that were merged and call defrag_get_extent() regardless of the minimum generation threshold ('newer_than' argument). A test case for fstests will be sent along soon. CC: stable(a)vger.kernel.org # 6.1+ Fixes: 199257a78bb0 ("btrfs: defrag: don't use merged extent map for their generation check") Reviewed-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> --- fs/btrfs/defrag.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/defrag.c b/fs/btrfs/defrag.c index b95ef44c326bd..968dae9539482 100644 --- a/fs/btrfs/defrag.c +++ b/fs/btrfs/defrag.c @@ -763,12 +763,12 @@ static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start, * We can get a merged extent, in that case, we need to re-search * tree to get the original em for defrag. * - * If @newer_than is 0 or em::generation < newer_than, we can trust - * this em, as either we don't care about the generation, or the - * merged extent map will be rejected anyway. + * This is because even if we have adjacent extents that are contiguous + * and compatible (same type and flags), we still want to defrag them + * so that we use less metadata (extent items in the extent tree and + * file extent items in the inode's subvolume tree). */ - if (em && (em->flags & EXTENT_FLAG_MERGED) && - newer_than && em->generation >= newer_than) { + if (em && (em->flags & EXTENT_FLAG_MERGED)) { free_extent_map(em); em = NULL; } -- 2.43.0

5 months, 3 weeks

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FAILED: Patch "mm: avoid unconditional one-tick sleep when swapcache_prepare fails" failed to apply to v6.6-stable tree

by Sasha Levin

The patch below does not apply to the v6.6-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>. Thanks, Sasha ------------------ original commit in Linus's tree ------------------ From 01626a18230246efdcea322aa8f067e60ffe5ccd Mon Sep 17 00:00:00 2001 From: Barry Song <v-songbaohua(a)oppo.com> Date: Fri, 27 Sep 2024 09:19:36 +1200 Subject: [PATCH] mm: avoid unconditional one-tick sleep when swapcache_prepare fails Commit 13ddaf26be32 ("mm/swap: fix race when skipping swapcache") introduced an unconditional one-tick sleep when `swapcache_prepare()` fails, which has led to reports of UI stuttering on latency-sensitive Android devices. To address this, we can use a waitqueue to wake up tasks that fail `swapcache_prepare()` sooner, instead of always sleeping for a full tick. While tasks may occasionally be woken by an unrelated `do_swap_page()`, this method is preferable to two scenarios: rapid re-entry into page faults, which can cause livelocks, and multiple millisecond sleeps, which visibly degrade user experience. Oven's testing shows that a single waitqueue resolves the UI stuttering issue. If a 'thundering herd' problem becomes apparent later, a waitqueue hash similar to `folio_wait_table[PAGE_WAIT_TABLE_SIZE]` for page bit locks can be introduced. [v-songbaohua(a)oppo.com: wake_up only when swapcache_wq waitqueue is active] Link: https://lkml.kernel.org/r/20241008130807.40833-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20240926211936.75373-1-21cnbao@gmail.com Fixes: 13ddaf26be32 ("mm/swap: fix race when skipping swapcache") Signed-off-by: Barry Song <v-songbaohua(a)oppo.com> Reported-by: Oven Liyang <liyangouwen1(a)oppo.com> Tested-by: Oven Liyang <liyangouwen1(a)oppo.com> Cc: Kairui Song <kasong(a)tencent.com> Cc: "Huang, Ying" <ying.huang(a)intel.com> Cc: Yu Zhao <yuzhao(a)google.com> Cc: David Hildenbrand <david(a)redhat.com> Cc: Chris Li <chrisl(a)kernel.org> Cc: Hugh Dickins <hughd(a)google.com> Cc: Johannes Weiner <hannes(a)cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org> Cc: Michal Hocko <mhocko(a)suse.com> Cc: Minchan Kim <minchan(a)kernel.org> Cc: Yosry Ahmed <yosryahmed(a)google.com> Cc: SeongJae Park <sj(a)kernel.org> Cc: Kalesh Singh <kaleshsingh(a)google.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/memory.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 3ccee51adfbbd..bdf77a3ec47bc 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4187,6 +4187,8 @@ static struct folio *alloc_swap_folio(struct vm_fault *vmf) } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +static DECLARE_WAIT_QUEUE_HEAD(swapcache_wq); + /* * We enter with non-exclusive mmap_lock (to exclude vma changes, * but allow concurrent faults), and pte mapped but not yet locked. @@ -4199,6 +4201,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct folio *swapcache, *folio = NULL; + DECLARE_WAITQUEUE(wait, current); struct page *page; struct swap_info_struct *si = NULL; rmap_t rmap_flags = RMAP_NONE; @@ -4297,7 +4300,9 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) * Relax a bit to prevent rapid * repeated page faults. */ + add_wait_queue(&swapcache_wq, &wait); schedule_timeout_uninterruptible(1); + remove_wait_queue(&swapcache_wq, &wait); goto out_page; } need_clear_cache = true; @@ -4604,8 +4609,11 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) pte_unmap_unlock(vmf->pte, vmf->ptl); out: /* Clear the swap cache pin for direct swapin after PTL unlock */ - if (need_clear_cache) + if (need_clear_cache) { swapcache_clear(si, entry, nr_pages); + if (waitqueue_active(&swapcache_wq)) + wake_up(&swapcache_wq); + } if (si) put_swap_device(si); return ret; @@ -4620,8 +4628,11 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) folio_unlock(swapcache); folio_put(swapcache); } - if (need_clear_cache) + if (need_clear_cache) { swapcache_clear(si, entry, nr_pages); + if (waitqueue_active(&swapcache_wq)) + wake_up(&swapcache_wq); + } if (si) put_swap_device(si); return ret; -- 2.43.0

5 months, 3 weeks

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FAILED: Patch "cxl/port: Fix CXL port initialization order when the subsystem is built-in" failed to apply to v6.6-stable tree

by Sasha Levin

The patch below does not apply to the v6.6-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>. Thanks, Sasha ------------------ original commit in Linus's tree ------------------ From 6575b268157f37929948a8d1f3bafb3d7c055bc1 Mon Sep 17 00:00:00 2001 From: Dan Williams <dan.j.williams(a)intel.com> Date: Fri, 25 Oct 2024 12:32:55 -0700 Subject: [PATCH] cxl/port: Fix CXL port initialization order when the subsystem is built-in When the CXL subsystem is built-in the module init order is determined by Makefile order. That order violates expectations. The expectation is that cxl_acpi and cxl_mem can race to attach. If cxl_acpi wins the race, cxl_mem will find the enabled CXL root ports it needs. If cxl_acpi loses the race it will retrigger cxl_mem to attach via cxl_bus_rescan(). That flow only works if cxl_acpi can assume ports are enabled immediately upon cxl_acpi_probe() return. That in turn can only happen in the CONFIG_CXL_ACPI=y case if the cxl_port driver is registered before cxl_acpi_probe() runs. Fix up the order to prevent initialization failures. Ensure that cxl_port is built-in when cxl_acpi is also built-in, arrange for Makefile order to resolve the subsys_initcall() order of cxl_port and cxl_acpi, and arrange for Makefile order to resolve the device_initcall() (module_init()) order of the remaining objects. As for what contributed to this not being found earlier, the CXL regression environment, cxl_test, builds all CXL functionality as a module to allow to symbol mocking and other dynamic reload tests. As a result there is no regression coverage for the built-in case. Reported-by: Gregory Price <gourry(a)gourry.net> Closes: http://lore.kernel.org/20241004212504.1246-1-gourry@gourry.net Tested-by: Gregory Price <gourry(a)gourry.net> Fixes: 8dd2bc0f8e02 ("cxl/mem: Add the cxl_mem driver") Cc: stable(a)vger.kernel.org Cc: Davidlohr Bueso <dave(a)stgolabs.net> Cc: Jonathan Cameron <jonathan.cameron(a)huawei.com> Cc: Dave Jiang <dave.jiang(a)intel.com> Cc: Alison Schofield <alison.schofield(a)intel.com> Cc: Vishal Verma <vishal.l.verma(a)intel.com> Cc: Ira Weiny <ira.weiny(a)intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com> Reviewed-by: Ira Weiny <ira.weiny(a)intel.com> Tested-by: Alejandro Lucero <alucerop(a)amd.com> Reviewed-by: Alejandro Lucero <alucerop(a)amd.com> Signed-off-by: Dan Williams <dan.j.williams(a)intel.com> Link: https://patch.msgid.link/172988474904.476062.7961350937442459266.stgit@dwil… Signed-off-by: Ira Weiny <ira.weiny(a)intel.com> --- drivers/cxl/Kconfig | 1 + drivers/cxl/Makefile | 20 ++++++++++++++------ drivers/cxl/port.c | 17 ++++++++++++++++- 3 files changed, 31 insertions(+), 7 deletions(-) diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig index 29c192f20082c..876469e23f7a7 100644 --- a/drivers/cxl/Kconfig +++ b/drivers/cxl/Kconfig @@ -60,6 +60,7 @@ config CXL_ACPI default CXL_BUS select ACPI_TABLE_LIB select ACPI_HMAT + select CXL_PORT help Enable support for host managed device memory (HDM) resources published by a platform's ACPI CXL memory layout description. See diff --git a/drivers/cxl/Makefile b/drivers/cxl/Makefile index db321f48ba52e..2caa90fa4bf25 100644 --- a/drivers/cxl/Makefile +++ b/drivers/cxl/Makefile @@ -1,13 +1,21 @@ # SPDX-License-Identifier: GPL-2.0 + +# Order is important here for the built-in case: +# - 'core' first for fundamental init +# - 'port' before platform root drivers like 'acpi' so that CXL-root ports +# are immediately enabled +# - 'mem' and 'pmem' before endpoint drivers so that memdevs are +# immediately enabled +# - 'pci' last, also mirrors the hardware enumeration hierarchy obj-y += core/ -obj-$(CONFIG_CXL_PCI) += cxl_pci.o -obj-$(CONFIG_CXL_MEM) += cxl_mem.o +obj-$(CONFIG_CXL_PORT) += cxl_port.o obj-$(CONFIG_CXL_ACPI) += cxl_acpi.o obj-$(CONFIG_CXL_PMEM) += cxl_pmem.o -obj-$(CONFIG_CXL_PORT) += cxl_port.o +obj-$(CONFIG_CXL_MEM) += cxl_mem.o +obj-$(CONFIG_CXL_PCI) += cxl_pci.o -cxl_mem-y := mem.o -cxl_pci-y := pci.o +cxl_port-y := port.o cxl_acpi-y := acpi.o cxl_pmem-y := pmem.o security.o -cxl_port-y := port.o +cxl_mem-y := mem.o +cxl_pci-y := pci.o diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c index 861dde65768fe..9dc394295e1fc 100644 --- a/drivers/cxl/port.c +++ b/drivers/cxl/port.c @@ -208,7 +208,22 @@ static struct cxl_driver cxl_port_driver = { }, }; -module_cxl_driver(cxl_port_driver); +static int __init cxl_port_init(void) +{ + return cxl_driver_register(&cxl_port_driver); +} +/* + * Be ready to immediately enable ports emitted by the platform CXL root + * (e.g. cxl_acpi) when CONFIG_CXL_PORT=y. + */ +subsys_initcall(cxl_port_init); + +static void __exit cxl_port_exit(void) +{ + cxl_driver_unregister(&cxl_port_driver); +} +module_exit(cxl_port_exit); + MODULE_DESCRIPTION("CXL: Port enumeration and services"); MODULE_LICENSE("GPL v2"); MODULE_IMPORT_NS(CXL); -- 2.43.0

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