October 2019 - Linux-stable-mirror

[v2 PATCH] mm: thp: handle page cache THP correctly in PageTransCompoundMap

by Yang Shi

We have usecase to use tmpfs as QEMU memory backend and we would like to take the advantage of THP as well. But, our test shows the EPT is not PMD mapped even though the underlying THP are PMD mapped on host. The number showed by /sys/kernel/debug/kvm/largepage is much less than the number of PMD mapped shmem pages as the below: 7f2778200000-7f2878200000 rw-s 00000000 00:14 262232 /dev/shm/qemu_back_mem.mem.Hz2hSf (deleted) Size: 4194304 kB [snip] AnonHugePages: 0 kB ShmemPmdMapped: 579584 kB [snip] Locked: 0 kB cat /sys/kernel/debug/kvm/largepages 12 And some benchmarks do worse than with anonymous THPs. By digging into the code we figured out that commit 127393fbe597 ("mm: thp: kvm: fix memory corruption in KVM with THP enabled") checks if there is a single PTE mapping on the page for anonymous THP when setting up EPT map. But, the _mapcount < 0 check doesn't fit to page cache THP since every subpage of page cache THP would get _mapcount inc'ed once it is PMD mapped, so PageTransCompoundMap() always returns false for page cache THP. This would prevent KVM from setting up PMD mapped EPT entry. So we need handle page cache THP correctly. However, when page cache THP's PMD gets split, kernel just remove the map instead of setting up PTE map like what anonymous THP does. Before KVM calls get_user_pages() the subpages may get PTE mapped even though it is still a THP since the page cache THP may be mapped by other processes at the mean time. Checking its _mapcount and whether the THP has PTE mapped or not. Although this may report some false negative cases (PTE mapped by other processes), it looks not trivial to make this accurate. With this fix /sys/kernel/debug/kvm/largepage would show reasonable pages are PMD mapped by EPT as the below: 7fbeaee00000-7fbfaee00000 rw-s 00000000 00:14 275464 /dev/shm/qemu_back_mem.mem.SKUvat (deleted) Size: 4194304 kB [snip] AnonHugePages: 0 kB ShmemPmdMapped: 557056 kB [snip] Locked: 0 kB cat /sys/kernel/debug/kvm/largepages 271 And the benchmarks are as same as anonymous THPs. Signed-off-by: Yang Shi <yang.shi(a)linux.alibaba.com> Reported-by: Gang Deng <gavin.dg(a)linux.alibaba.com> Tested-by: Gang Deng <gavin.dg(a)linux.alibaba.com> Suggested-by: Hugh Dickins <hughd(a)google.com> Cc: Andrea Arcangeli <aarcange(a)redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com> Cc: <stable(a)vger.kernel.org> 4.8+ --- v2: Adopted the suggestion from Hugh to use _mapcount and compound_mapcount. But I just open coding compound_mapcount to avoid duplicating the definition of compound_mapcount_ptr in two different files. Since "compound_mapcount" looks self-explained so I'm supposed the open coding would not affect the readability. include/linux/page-flags.h | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index f91cb88..954a877 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -622,12 +622,30 @@ static inline int PageTransCompound(struct page *page) * * Unlike PageTransCompound, this is safe to be called only while * split_huge_pmd() cannot run from under us, like if protected by the - * MMU notifier, otherwise it may result in page->_mapcount < 0 false + * MMU notifier, otherwise it may result in page->_mapcount check false * positives. + * + * We have to treat page cache THP differently since every subpage of it + * would get _mapcount inc'ed once it is PMD mapped. But, it may be PTE + * mapped in the current process so comparing subpage's _mapcount to + * compound_mapcount ot filter out PTE mapped case. */ static inline int PageTransCompoundMap(struct page *page) { - return PageTransCompound(page) && atomic_read(&page->_mapcount) < 0; + struct page *head; + int map_count; + + if (!PageTransCompound(page)) + return 0; + + if (PageAnon(page)) + return atomic_read(&page->_mapcount) < 0; + + head = compound_head(page); + map_count = atomic_read(&page->_mapcount); + /* File THP is PMD mapped and not double mapped */ + return map_count >= 0 && + map_count == atomic_read(&head[1].compound_mapcount); } /* -- 1.8.3.1

5 years, 2 months

3
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[PATCH] of: reserved_mem: add missing of_node_put() for proper ref-counting

by Chris Goldsworthy

Commit d698a388146c ("of: reserved-memory: ignore disabled memory-region nodes") added an early return in of_reserved_mem_device_init_by_idx(), but didn't call of_node_put() on a device_node whose ref-count was incremented in the call to of_parse_phandle() preceding the early exit. Fixes: d698a388146c ("of: reserved-memory: ignore disabled memory-region nodes") Signed-off-by: Chris Goldsworthy <cgoldswo(a)codeaurora.org> To: Rob Herring <robh+dt(a)kernel.org> Cc: devicetree(a)vger.kernel.org Cc: stable(a)vger.kernel.org Cc: linux-kernel(a)vger.kernel.org Cc: linux-arm-msm(a)vger.kernel.org Cc: linux-arm-kernel(a)lists.infradead.org --- drivers/of/of_reserved_mem.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index 7989703..6bd610e 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -324,8 +324,10 @@ int of_reserved_mem_device_init_by_idx(struct device *dev, if (!target) return -ENODEV; - if (!of_device_is_available(target)) + if (!of_device_is_available(target)) { + of_node_put(target); return 0; + } rmem = __find_rmem(target); of_node_put(target); -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project

5 years, 2 months

4
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[v3 PATCH] mm: thp: handle page cache THP correctly in PageTransCompoundMap

by Yang Shi

We have usecase to use tmpfs as QEMU memory backend and we would like to take the advantage of THP as well. But, our test shows the EPT is not PMD mapped even though the underlying THP are PMD mapped on host. The number showed by /sys/kernel/debug/kvm/largepage is much less than the number of PMD mapped shmem pages as the below: 7f2778200000-7f2878200000 rw-s 00000000 00:14 262232 /dev/shm/qemu_back_mem.mem.Hz2hSf (deleted) Size: 4194304 kB [snip] AnonHugePages: 0 kB ShmemPmdMapped: 579584 kB [snip] Locked: 0 kB cat /sys/kernel/debug/kvm/largepages 12 And some benchmarks do worse than with anonymous THPs. By digging into the code we figured out that commit 127393fbe597 ("mm: thp: kvm: fix memory corruption in KVM with THP enabled") checks if there is a single PTE mapping on the page for anonymous THP when setting up EPT map. But, the _mapcount < 0 check doesn't fit to page cache THP since every subpage of page cache THP would get _mapcount inc'ed once it is PMD mapped, so PageTransCompoundMap() always returns false for page cache THP. This would prevent KVM from setting up PMD mapped EPT entry. So we need handle page cache THP correctly. However, when page cache THP's PMD gets split, kernel just remove the map instead of setting up PTE map like what anonymous THP does. Before KVM calls get_user_pages() the subpages may get PTE mapped even though it is still a THP since the page cache THP may be mapped by other processes at the mean time. Checking its _mapcount and whether the THP has PTE mapped or not. Although this may report some false negative cases (PTE mapped by other processes), it looks not trivial to make this accurate. With this fix /sys/kernel/debug/kvm/largepage would show reasonable pages are PMD mapped by EPT as the below: 7fbeaee00000-7fbfaee00000 rw-s 00000000 00:14 275464 /dev/shm/qemu_back_mem.mem.SKUvat (deleted) Size: 4194304 kB [snip] AnonHugePages: 0 kB ShmemPmdMapped: 557056 kB [snip] Locked: 0 kB cat /sys/kernel/debug/kvm/largepages 271 And the benchmarks are as same as anonymous THPs. Signed-off-by: Yang Shi <yang.shi(a)linux.alibaba.com> Reported-by: Gang Deng <gavin.dg(a)linux.alibaba.com> Tested-by: Gang Deng <gavin.dg(a)linux.alibaba.com> Suggested-by: Hugh Dickins <hughd(a)google.com> Cc: Andrea Arcangeli <aarcange(a)redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov(a)linux.intel.com> Cc: Matthew Wilcox <willy(a)infradead.org> Cc: <stable(a)vger.kernel.org> 4.8+ --- v3: Took the suggestion from Willy to move the definition of compound_mapcount_ptr to mm_types.h in order to use it instead of open coding it. v2: Adopted the suggestion from Hugh to use _mapcount and compound_mapcount. But I just open coding compound_mapcount to avoid duplicating the definition of compound_mapcount_ptr in two different files. Since "compound_mapcount" looks self-explained so I'm supposed the open coding would not affect the readability. include/linux/mm.h | 5 ----- include/linux/mm_types.h | 5 +++++ include/linux/page-flags.h | 22 ++++++++++++++++++++-- 3 files changed, 25 insertions(+), 7 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index cc29227..a2adf95 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -695,11 +695,6 @@ static inline void *kvcalloc(size_t n, size_t size, gfp_t flags) extern void kvfree(const void *addr); -static inline atomic_t *compound_mapcount_ptr(struct page *page) -{ - return &page[1].compound_mapcount; -} - static inline int compound_mapcount(struct page *page) { VM_BUG_ON_PAGE(!PageCompound(page), page); diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 2222fa7..270aa8f 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -221,6 +221,11 @@ struct page { #endif } _struct_page_alignment; +static inline atomic_t *compound_mapcount_ptr(struct page *page) +{ + return &page[1].compound_mapcount; +} + /* * Used for sizing the vmemmap region on some architectures */ diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index f91cb88..e0f2d53 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -622,12 +622,30 @@ static inline int PageTransCompound(struct page *page) * * Unlike PageTransCompound, this is safe to be called only while * split_huge_pmd() cannot run from under us, like if protected by the - * MMU notifier, otherwise it may result in page->_mapcount < 0 false + * MMU notifier, otherwise it may result in page->_mapcount check false * positives. + * + * We have to treat page cache THP differently since every subpage of it + * would get _mapcount inc'ed once it is PMD mapped. But, it may be PTE + * mapped in the current process so comparing subpage's _mapcount to + * compound_mapcount ot filter out PTE mapped case. */ static inline int PageTransCompoundMap(struct page *page) { - return PageTransCompound(page) && atomic_read(&page->_mapcount) < 0; + struct page *head; + int map_count; + + if (!PageTransCompound(page)) + return 0; + + if (PageAnon(page)) + return atomic_read(&page->_mapcount) < 0; + + head = compound_head(page); + map_count = atomic_read(&page->_mapcount); + /* File THP is PMD mapped and not double mapped */ + return map_count >= 0 && + map_count == atomic_read(compound_mapcount_ptr(head)); } /* -- 1.8.3.1

5 years, 2 months

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[RESEND PATCH] ASoC: rsnd: dma: fix SSI9 4/5/6/7 busif dma address

by Eugeniu Rosca

From: Jiada Wang <jiada_wang(a)mentor.com> Currently each SSI unit's busif dma address is calculated by following calculation formula: 0xec540000 + 0x1000 * id + busif / 4 * 0xA000 + busif % 4 * 0x400 But according to R-Car3 HW manual 41.1.4 Register Configuration, ssi9 4/5/6/7 busif data register address (SSI9_4_BUSIF/SSI9_5_BUSIF/SSI9_6_BUSIF/SSI9_7_BUSIF) are out of this rule. This patch updates the calculation formula to correct ssi9 4/5/6/7 busif data register address. Fixes: 5e45a6fab3b9 ("ASoc: rsnd: dma: Calculate dma address with consider of BUSIF") Signed-off-by: Jiada Wang <jiada_wang(a)mentor.com> Signed-off-by: Timo Wischer <twischer(a)de.adit-jv.com> [erosca: minor improvements in commit description] Cc: Andrew Gabbasov <andrew_gabbasov(a)mentor.com> Cc: stable(a)vger.kernel.org # v4.20+ Signed-off-by: Eugeniu Rosca <erosca(a)de.adit-jv.com> --- Originally submitted as https://patchwork.kernel.org/patch/10825513/ ("ASoC: rsnd: dma: fix SSI9 4/5/6/7 busif dma address") --- sound/soc/sh/rcar/dma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sound/soc/sh/rcar/dma.c b/sound/soc/sh/rcar/dma.c index 0324a5c39619..28f65eba2bb4 100644 --- a/sound/soc/sh/rcar/dma.c +++ b/sound/soc/sh/rcar/dma.c @@ -508,10 +508,10 @@ static struct rsnd_mod_ops rsnd_dmapp_ops = { #define RDMA_SSI_I_N(addr, i) (addr ##_reg - 0x00300000 + (0x40 * i) + 0x8) #define RDMA_SSI_O_N(addr, i) (addr ##_reg - 0x00300000 + (0x40 * i) + 0xc) -#define RDMA_SSIU_I_N(addr, i, j) (addr ##_reg - 0x00441000 + (0x1000 * (i)) + (((j) / 4) * 0xA000) + (((j) % 4) * 0x400)) +#define RDMA_SSIU_I_N(addr, i, j) (addr ##_reg - 0x00441000 + (0x1000 * (i)) + (((j) / 4) * 0xA000) + (((j) % 4) * 0x400) - (0x4000 * ((i) / 9) * ((j) / 4))) #define RDMA_SSIU_O_N(addr, i, j) RDMA_SSIU_I_N(addr, i, j) -#define RDMA_SSIU_I_P(addr, i, j) (addr ##_reg - 0x00141000 + (0x1000 * (i)) + (((j) / 4) * 0xA000) + (((j) % 4) * 0x400)) +#define RDMA_SSIU_I_P(addr, i, j) (addr ##_reg - 0x00141000 + (0x1000 * (i)) + (((j) / 4) * 0xA000) + (((j) % 4) * 0x400) - (0x4000 * ((i) / 9) * ((j) / 4))) #define RDMA_SSIU_O_P(addr, i, j) RDMA_SSIU_I_P(addr, i, j) #define RDMA_SRC_I_N(addr, i) (addr ##_reg - 0x00500000 + (0x400 * i)) -- 2.23.0

5 years, 2 months

3
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[PATCH v4 2/2] sched/topology: Allow sched_asym_cpucapacity to be disabled

by Valentin Schneider

While the static key is correctly initialized as being disabled, it will remain forever enabled once turned on. This means that if we start with an asymmetric system and hotplug out enough CPUs to end up with an SMP system, the static key will remain set - which is obviously wrong. We should detect this and turn off things like misfit migration and capacity aware wakeups. As Quentin pointed out, having separate root domains makes this slightly trickier. We could have exclusive cpusets that create an SMP island - IOW, the domains within this root domain will not see any asymmetry. This means we can't just disable the key on domain destruction, we need to count how many asymmetric root domains we have. Consider the following example using Juno r0 which is 2+4 big.LITTLE, where two identical cpusets are created: they both span both big and LITTLE CPUs: asym0 asym1 [ ][ ] L L B L L B cgcreate -g cpuset:asym0 cgset -r cpuset.cpus=0,1,3 asym0 cgset -r cpuset.mems=0 asym0 cgset -r cpuset.cpu_exclusive=1 asym0 cgcreate -g cpuset:asym1 cgset -r cpuset.cpus=2,4,5 asym1 cgset -r cpuset.mems=0 asym1 cgset -r cpuset.cpu_exclusive=1 asym1 cgset -r cpuset.sched_load_balance=0 . (the CPU numbering may look odd because on the Juno LITTLEs are CPUs 0,3-5 and bigs are CPUs 1-2) If we make one of those SMP (IOW remove asymmetry) by e.g. hotplugging its big core, we would end up with an SMP cpuset and an asymmetric cpuset - the static key must remain set, because we still have one asymmetric root domain. With the above example, this could be done with: echo 0 > /sys/devices/system/cpu/cpu2/online Which would result in: asym0 asym1 [ ][ ] L L B L L When both SMP and asymmetric cpusets are present, all CPUs will observe sched_asym_cpucapacity being set (it is system-wide), but not all CPUs observe asymmetry in their sched domain hierarchy: per_cpu(sd_asym_cpucapacity, <any CPU in asym0>) == <some SD at DIE level> per_cpu(sd_asym_cpucapacity, <any CPU in asym1>) == NULL Change the simple key enablement to an increment, and decrement the key counter when destroying domains that cover asymmetric CPUs. Cc: <stable(a)vger.kernel.org> Fixes: df054e8445a4 ("sched/topology: Add static_key for asymmetric CPU capacity optimizations") Reviewed-by: Dietmar Eggemann <dietmar.eggemann(a)arm.com> Signed-off-by: Valentin Schneider <valentin.schneider(a)arm.com> --- kernel/sched/topology.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 2e7af755e17a..6ec1e595b1d4 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -2026,7 +2026,7 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att rcu_read_unlock(); if (has_asym) - static_branch_enable_cpuslocked(&sched_asym_cpucapacity); + static_branch_inc_cpuslocked(&sched_asym_cpucapacity); if (rq && sched_debug_enabled) { pr_info("root domain span: %*pbl (max cpu_capacity = %lu)\n", @@ -2121,9 +2121,12 @@ int sched_init_domains(const struct cpumask *cpu_map) */ static void detach_destroy_domains(const struct cpumask *cpu_map) { + unsigned int cpu = cpumask_any(cpu_map); int i; + if (rcu_access_pointer(per_cpu(sd_asym_cpucapacity, cpu))) + static_branch_dec_cpuslocked(&sched_asym_cpucapacity); + rcu_read_lock(); for_each_cpu(i, cpu_map) cpu_attach_domain(NULL, &def_root_domain, i); -- 2.22.0

5 years, 2 months

1
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[PATCH 1/2] perf/x86/amd/ibs: Fix reading of the IBS OpData register and thus precise RIP validity

by Kim Phillips

The loop that reads all the IBS MSRs into *buf stopped one MSR short of reading the IbsOpData register, which contains the RipInvalid status bit. Fix the offset_max assignment so the MSR gets read, so the RIP invalid evaluation is based on what the IBS h/w output, instead of what was left in memory. Signed-off-by: Kim Phillips <kim.phillips(a)amd.com> Fixes: d47e8238cd76 ("perf/x86-ibs: Take instruction pointer from ibs sample") Cc: stable(a)vger.kernel.org Cc: Stephane Eranian <eranian(a)google.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Arnaldo Carvalho de Melo <acme(a)kernel.org> Cc: Alexander Shishkin <alexander.shishkin(a)linux.intel.com> Cc: Jiri Olsa <jolsa(a)redhat.com> Cc: Namhyung Kim <namhyung(a)kernel.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Borislav Petkov <bp(a)alien8.de> Cc: "H. Peter Anvin" <hpa(a)zytor.com> Cc: x86(a)kernel.org Cc: linux-kernel(a)vger.kernel.org --- arch/x86/events/amd/ibs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c index 5b35b7ea5d72..98ba21a588a1 100644 --- a/arch/x86/events/amd/ibs.c +++ b/arch/x86/events/amd/ibs.c @@ -614,7 +614,7 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs) if (event->attr.sample_type & PERF_SAMPLE_RAW) offset_max = perf_ibs->offset_max; else if (check_rip) - offset_max = 2; + offset_max = 3; else offset_max = 1; do { -- 2.23.0

5 years, 2 months

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[PATCH v3 1/2] sched/topology: Don't try to build empty sched domains

by Valentin Schneider

Turns out hotplugging CPUs that are in exclusive cpusets can lead to the cpuset code feeding empty cpumasks to the sched domain rebuild machinery. This leads to the following splat: [ 30.618174] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 30.623697] Modules linked in: [ 30.626731] CPU: 0 PID: 235 Comm: kworker/5:2 Not tainted 5.4.0-rc1-00005-g8d495477d62e #23 [ 30.635003] Hardware name: ARM Juno development board (r0) (DT) [ 30.640877] Workqueue: events cpuset_hotplug_workfn [ 30.645713] pstate: 60000005 (nZCv daif -PAN -UAO) [ 30.650464] pc : build_sched_domains (./include/linux/arch_topology.h:23 kernel/sched/topology.c:1898 kernel/sched/topology.c:1969) [ 30.655126] lr : build_sched_domains (kernel/sched/topology.c:1966) [...] [ 30.742047] Call trace: [ 30.744474] build_sched_domains (./include/linux/arch_topology.h:23 kernel/sched/topology.c:1898 kernel/sched/topology.c:1969) [ 30.748793] partition_sched_domains_locked (kernel/sched/topology.c:2250) [ 30.753971] rebuild_sched_domains_locked (./include/linux/bitmap.h:370 ./include/linux/cpumask.h:538 kernel/cgroup/cpuset.c:955 kernel/cgroup/cpuset.c:978 kernel/cgroup/cpuset.c:1019) [ 30.758977] rebuild_sched_domains (kernel/cgroup/cpuset.c:1032) [ 30.763209] cpuset_hotplug_workfn (kernel/cgroup/cpuset.c:3205 (discriminator 2)) [ 30.767613] process_one_work (./arch/arm64/include/asm/jump_label.h:21 ./include/linux/jump_label.h:200 ./include/trace/events/workqueue.h:114 kernel/workqueue.c:2274) [ 30.771586] worker_thread (./include/linux/compiler.h:199 ./include/linux/list.h:268 kernel/workqueue.c:2416) [ 30.775217] kthread (kernel/kthread.c:255) [ 30.778418] ret_from_fork (arch/arm64/kernel/entry.S:1167) [ 30.781965] Code: f860dae2 912802d6 aa1603e1 12800000 (f8616853) The faulty line in question is cap = arch_scale_cpu_capacity(cpumask_first(cpu_map)); and we're not checking the return value against nr_cpu_ids (we shouldn't have to!), which leads to the above. Prevent generate_sched_domains() from returning empty cpumasks, and add some assertion in build_sched_domains() to scream bloody murder if it happens again. The above splat was obtained on my Juno r0 with: cgcreate -g cpuset:asym cgset -r cpuset.cpus=0-3 asym cgset -r cpuset.mems=0 asym cgset -r cpuset.cpu_exclusive=1 asym cgcreate -g cpuset:smp cgset -r cpuset.cpus=4-5 smp cgset -r cpuset.mems=0 smp cgset -r cpuset.cpu_exclusive=1 smp cgset -r cpuset.sched_load_balance=0 . echo 0 > /sys/devices/system/cpu/cpu4/online echo 0 > /sys/devices/system/cpu/cpu5/online Cc: <stable(a)vger.kernel.org> Fixes: 05484e098448 ("sched/topology: Add SD_ASYM_CPUCAPACITY flag detection") Signed-off-by: Valentin Schneider <valentin.schneider(a)arm.com> --- kernel/cgroup/cpuset.c | 8 ++++++++ kernel/sched/topology.c | 5 ++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index c52bc91f882b..a859e5539440 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -817,6 +817,11 @@ static int generate_sched_domains(cpumask_var_t **domains, struct cpuset *a = csa[i]; int apn = a->pn; + if (cpumask_empty(a->effective_cpus)) { + ndoms--; + continue; + } + for (j = 0; j < csn; j++) { struct cpuset *b = csa[j]; int bpn = b->pn; @@ -859,6 +864,9 @@ static int generate_sched_domains(cpumask_var_t **domains, continue; } + if (cpumask_empty(a->effective_cpus)) + continue; + dp = doms[nslot]; if (nslot == ndoms) { diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index b5667a273bf6..9318acf1d1fe 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1948,7 +1948,7 @@ static struct sched_domain_topology_level static int build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *attr) { - enum s_alloc alloc_state; + enum s_alloc alloc_state = sa_none; struct sched_domain *sd; struct s_data d; struct rq *rq = NULL; @@ -1956,6 +1956,9 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att struct sched_domain_topology_level *tl_asym; bool has_asym = false; + if (WARN_ON(cpumask_empty(cpu_map))) + goto error; + alloc_state = __visit_domain_allocation_hell(&d, cpu_map); if (alloc_state != sa_rootdomain) goto error; -- 2.22.0

5 years, 2 months

2
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[tip: timers/urgent] lib/vdso: Make clock_getres() POSIX compliant again

by tip-bot2 for Thomas Gleixner

The following commit has been merged into the timers/urgent branch of tip: Commit-ID: 1638b8f096ca165965189b9626564c933c79fe63 Gitweb: https://git.kernel.org/tip/1638b8f096ca165965189b9626564c933c79fe63 Author: Thomas Gleixner <tglx(a)linutronix.de> AuthorDate: Mon, 21 Oct 2019 12:07:15 +02:00 Committer: Thomas Gleixner <tglx(a)linutronix.de> CommitterDate: Wed, 23 Oct 2019 14:48:23 +02:00 lib/vdso: Make clock_getres() POSIX compliant again A recent commit removed the NULL pointer check from the clock_getres() implementation causing a test case to fault. POSIX requires an explicit NULL pointer check for clock_getres() aside of the validity check of the clock_id argument for obscure reasons. Add it back for both 32bit and 64bit. Note, this is only a partial revert of the offending commit which does not bring back the broken fallback invocation in the the 32bit compat implementations of clock_getres() and clock_gettime(). Fixes: a9446a906f52 ("lib/vdso/32: Remove inconsistent NULL pointer checks") Reported-by: Andreas Schwab <schwab(a)linux-m68k.org> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Tested-by: Christophe Leroy <christophe.leroy(a)c-s.fr> Cc: stable(a)vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1910211202260.1904@nanos.tec.linu… --- lib/vdso/gettimeofday.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c index e630e7f..45f57fd 100644 --- a/lib/vdso/gettimeofday.c +++ b/lib/vdso/gettimeofday.c @@ -214,9 +214,10 @@ int __cvdso_clock_getres_common(clockid_t clock, struct __kernel_timespec *res) return -1; } - res->tv_sec = 0; - res->tv_nsec = ns; - + if (likely(res)) { + res->tv_sec = 0; + res->tv_nsec = ns; + } return 0; } @@ -245,7 +246,7 @@ __cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res) ret = clock_getres_fallback(clock, &ts); #endif - if (likely(!ret)) { + if (likely(!ret && res)) { res->tv_sec = ts.tv_sec; res->tv_nsec = ts.tv_nsec; }

5 years, 2 months

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[PATCH V3] rtlwifi: rtl_pci: Fix problem of too small skb->len

by Larry Finger

In commit 8020919a9b99 ("mac80211: Properly handle SKB with radiotap only"), buffers whose length is too short cause a WARN_ON(1) to be executed. This change exposed a fault in rtlwifi drivers, which is fixed by regarding packets with skb->len <= FCS_LEN as though they are in error and dropping them. The test is now annotated as likely. Cc: Stable <stable(a)vger.kernel.org> # v5.0+ Signed-off-by: Larry Finger <Larry.Finger(a)lwfinger.net> --- V2 - content dropped V3 - changed fix to drop packet rather than arbitrarily increasing the length. --- Material for 5.4. --- drivers/net/wireless/realtek/rtlwifi/pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/realtek/rtlwifi/pci.c b/drivers/net/wireless/realtek/rtlwifi/pci.c index 6087ec7a90a6..f88d26535978 100644 --- a/drivers/net/wireless/realtek/rtlwifi/pci.c +++ b/drivers/net/wireless/realtek/rtlwifi/pci.c @@ -822,7 +822,7 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw) hdr = rtl_get_hdr(skb); fc = rtl_get_fc(skb); - if (!stats.crc && !stats.hwerror) { + if (!stats.crc && !stats.hwerror && (skb->len > FCS_LEN)) { memcpy(IEEE80211_SKB_RXCB(skb), &rx_status, sizeof(rx_status)); @@ -859,6 +859,7 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw) _rtl_pci_rx_to_mac80211(hw, skb, rx_status); } } else { + /* drop packets with errors or those too short */ dev_kfree_skb_any(skb); } new_trx_end: -- 2.23.0

5 years, 2 months

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[PATCH] usb: xhci: fix Immediate Data Transfer endianness

by Samuel Holland

The arguments to queue_trb are always byteswapped to LE for placement in the ring, but this should not happen in the case of immediate data; the bytes copied out of transfer_buffer are already in the correct order. Add a complementary byteswap so the bytes end up in the ring correctly. This was observed on BE ppc64 with a "Texas Instruments TUSB73x0 SuperSpeed USB 3.0 xHCI Host Controller [104c:8241]" as a ch341 usb-serial adapter ("1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter") always transmitting the same character (generally NUL) over the serial link regardless of the key pressed. Cc: stable(a)vger.kernel.org Fixes: 33e39350ebd2 ("usb: xhci: add Immediate Data Transfer support") Signed-off-by: Samuel Holland <samuel(a)sholland.org> --- drivers/usb/host/xhci-ring.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 85ceb43e3405..e7aab31fd9a5 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -3330,6 +3330,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, if (xhci_urb_suitable_for_idt(urb)) { memcpy(&send_addr, urb->transfer_buffer, trb_buff_len); + le64_to_cpus(&send_addr); field |= TRB_IDT; } } @@ -3475,6 +3476,7 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags, if (xhci_urb_suitable_for_idt(urb)) { memcpy(&addr, urb->transfer_buffer, urb->transfer_buffer_length); + le64_to_cpus(&addr); field |= TRB_IDT; } else { addr = (u64) urb->transfer_dma; -- 2.21.0

5 years, 2 months

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Linux-stable-mirror October 2019