- 17 Jun, 2022 30 commits
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Waiman Long authored
There are 3 RCU-based object iteration loops in kmemleak_scan(). Because of the need to take RCU read lock, we can't insert cond_resched() into the loop like other parts of the function. As there can be millions of objects to be scanned, it takes a while to iterate all of them. The kmemleak functionality is usually enabled in a debug kernel which is much slower than a non-debug kernel. With sufficient number of kmemleak objects, the time to iterate them all may exceed 22s causing soft lockup. watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [kmemleak:625] In this particular bug report, the soft lockup happen in the 2nd iteration loop. In the 2nd and 3rd loops, most of the objects are checked and then skipped under the object lock. Only a selected fews are modified. Those objects certainly need lock protection. However, the lock/unlock operation is slow especially with interrupt disabling and enabling included. We can actually do some basic check like color_white() without taking the lock and skip the object accordingly. Of course, this kind of check is racy and may miss objects that are being modified concurrently. The cost of missed objects, however, is just that they will be discovered in the next scan instead. The advantage of doing so is that iteration can be done much faster especially with LOCKDEP enabled in a debug kernel. With a debug kernel running on a 2-socket 96-thread x86-64 system (HZ=1000), the 2nd and 3rd iteration loops speedup with this patch on the first kmemleak_scan() call after bootup is shown in the table below. Before patch After patch Loop # # of objects Elapsed time # of objects Elapsed time ------ ------------ ------------ ------------ ------------ 2 2,599,850 2.392s 2,596,364 0.266s 3 2,600,176 2.171s 2,597,061 0.260s This patch reduces loop iteration times by about 88%. This will greatly reduce the chance of a soft lockup happening in the 2nd or 3rd iteration loops. Even though the first loop runs a little bit faster, it can still be problematic if many kmemleak objects are there. As the object count has to be modified in every object, we cannot avoid taking the object lock. So other way to prevent soft lockup will be needed. Link: https://lkml.kernel.org/r/20220614220359.59282-3-longman@redhat.comSigned-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Waiman Long authored
Patch series "mm/kmemleak: Avoid soft lockup in kmemleak_scan()", v2. There are 3 RCU-based object iteration loops in kmemleak_scan(). Because of the need to take RCU read lock, we can't insert cond_resched() into the loop like other parts of the function. As there can be millions of objects to be scanned, it takes a while to iterate all of them. The kmemleak functionality is usually enabled in a debug kernel which is much slower than a non-debug kernel. With sufficient number of kmemleak objects, the time to iterate them all may exceed 22s causing soft lockup. watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [kmemleak:625] This patch series make changes to the 3 object iteration loops in kmemleak_scan() to prevent them from causing soft lockup. This patch (of 3): kmemleak_scan() is called only from the kmemleak scan thread or from write to the kmemleak debugfs file. Both are in task context and so we can directly use the simpler _irq() lock/unlock calls instead of the more complex _irqsave/_irqrestore variants. Similarly, kmemleak_clear() is called only from write to the kmemleak debugfs file. The same change can be applied. Link: https://lkml.kernel.org/r/20220614220359.59282-1-longman@redhat.com Link: https://lkml.kernel.org/r/20220614220359.59282-2-longman@redhat.comSigned-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Gautam Menghani authored
Remove unnecessary initialization for the variable 'next'. This fixes the clang scan warning: Value stored to 'next' during its initialization is never read [deadcode.DeadStores] Link: https://lkml.kernel.org/r/20220612182320.160651-1-gautammenghani201@gmail.comSigned-off-by: Gautam Menghani <gautammenghani201@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Joel Savitz authored
Commit 17de1e55 ("selftests: clarify common error when running gup_test") had most of its hunks dropped due to a conflict with another patch accepted into Linux around the same time that implemented the same behavior as a subset of other changes. However, the remaining hunk defines the GUP_TEST_FILE macro without making use of it. This patch makes use of the macro in the two relevant places. Furthermore, the above mentioned commit's log message erroneously describes the changes that were dropped from the patch. This patch corrects the record. Link: https://lkml.kernel.org/r/20220609203217.3206247-1-jsavitz@redhat.com Fixes: 17de1e55 ("selftests: clarify common error when running gup_test") Signed-off-by: Joel Savitz <jsavitz@redhat.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Acked-by: Nico Pache <npache@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Xiang wangx authored
Delete the redundant word 'in'. Link: https://lkml.kernel.org/r/20220610071244.59679-1-wangxiang@cdjrlc.comSigned-off-by: Xiang wangx <wangxiang@cdjrlc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Vasily Averin authored
__register_pernet_operations() executes init hook of registered pernet_operation structure in all existing net namespaces. Typically, these hooks are called by a process associated with the specified net namespace, and all __GFP_ACCOUNT marked allocation are accounted for corresponding container/memcg. However __register_pernet_operations() calls the hooks in the same context, and as a result all marked allocations are accounted to one memcg for all processed net namespaces. This patch adjusts active memcg for each net namespace and helps to account memory allocated inside ops_init() into the proper memcg. Link: https://lkml.kernel.org/r/f9394752-e272-9bf9-645f-a18c56d1c4ec@openvz.orgSigned-off-by: Vasily Averin <vvs@openvz.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Shakeel Butt <shakeelb@google.com> Cc: Michal Koutný <mkoutny@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Florian Westphal <fw@strlen.de> Cc: David S. Miller <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Linux Kernel Functional Testing <lkft@linaro.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Roman Gushchin authored
Currently mem_cgroup_from_obj() is not working properly with objects allocated using vmalloc(). It creates problems in some cases, when it's called for static objects belonging to modules or generally allocated using vmalloc(). This patch makes mem_cgroup_from_obj() safe to be called on objects allocated using vmalloc(). It also introduces mem_cgroup_from_slab_obj(), which is a faster version to use in places when we know the object is either a slab object or a generic slab page (e.g. when adding an object to a lru list). Link: https://lkml.kernel.org/r/20220610180310.1725111-1-roman.gushchin@linux.devSuggested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Acked-by: Shakeel Butt <shakeelb@google.com> Tested-by: Vasily Averin <vvs@openvz.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Qian Cai <quic_qiancai@quicinc.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Miaohe Lin authored
Think about the below scene: CPU1 CPU2 memunmap_pages percpu_ref_exit __percpu_ref_exit free_percpu(percpu_count); /* percpu_count is freed here! */ get_dev_pagemap xa_load(&pgmap_array, PHYS_PFN(phys)) /* pgmap still in the pgmap_array */ percpu_ref_tryget_live(&pgmap->ref) if __ref_is_percpu /* __PERCPU_REF_ATOMIC_DEAD not set yet */ this_cpu_inc(*percpu_count) /* access freed percpu_count here! */ ref->percpu_count_ptr = __PERCPU_REF_ATOMIC_DEAD; /* too late... */ pageunmap_range To fix the issue, do percpu_ref_exit() after pgmap_array is emptied. So we won't do percpu_ref_tryget_live() against a being freed percpu_ref. Link: https://lkml.kernel.org/r/20220609121305.2508-1-linmiaohe@huawei.com Fixes: b7b3c01b ("mm/memremap_pages: support multiple ranges per invocation") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patrick Wang authored
Check the physical address of objects for its boundary when scan instead of in kmemleak_*_phys(). Link: https://lkml.kernel.org/r/20220611035551.1823303-5-patrick.wang.shcn@gmail.com Fixes: 23c2d497 ("mm: kmemleak: take a full lowmem check in kmemleak_*_phys()") Signed-off-by: Patrick Wang <patrick.wang.shcn@gmail.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Yee Lee <yee.lee@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patrick Wang authored
Add object_phys_tree_root to store the objects allocated with physical address. Distinguish it from object_tree_root by OBJECT_PHYS flag or function argument. The physical address is stored directly in those objects. Link: https://lkml.kernel.org/r/20220611035551.1823303-4-patrick.wang.shcn@gmail.comSigned-off-by: Patrick Wang <patrick.wang.shcn@gmail.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Yee Lee <yee.lee@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patrick Wang authored
Add OBJECT_PHYS flag for object. This flag is used to identify the objects allocated with physical address. The create_object_phys() function is added as well to set that flag and is used by kmemleak_alloc_phys(). Link: https://lkml.kernel.org/r/20220611035551.1823303-3-patrick.wang.shcn@gmail.comSigned-off-by: Patrick Wang <patrick.wang.shcn@gmail.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Yee Lee <yee.lee@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patrick Wang authored
Patch series "mm: kmemleak: store objects allocated with physical address separately and check when scan", v4. The kmemleak_*_phys() interface uses "min_low_pfn" and "max_low_pfn" to check address. But on some architectures, kmemleak_*_phys() is called before those two variables initialized. The following steps will be taken: 1) Add OBJECT_PHYS flag and rbtree for the objects allocated with physical address 2) Store physical address in objects if allocated with OBJECT_PHYS 3) Check the boundary when scan instead of in kmemleak_*_phys() This patch set will solve: https://lore.kernel.org/r/20220527032504.30341-1-yee.lee@mediatek.com https://lore.kernel.org/r/9dd08bb5-f39e-53d8-f88d-bec598a08c93@gmail.com v3: https://lore.kernel.org/r/20220609124950.1694394-1-patrick.wang.shcn@gmail.com v2: https://lore.kernel.org/r/20220603035415.1243913-1-patrick.wang.shcn@gmail.com v1: https://lore.kernel.org/r/20220531150823.1004101-1-patrick.wang.shcn@gmail.com This patch (of 4): Remove the unused kmemleak_not_leak_phys() function. And remove the min_count argument to kmemleak_alloc_phys() function, assume it's 0. Link: https://lkml.kernel.org/r/20220611035551.1823303-1-patrick.wang.shcn@gmail.com Link: https://lkml.kernel.org/r/20220611035551.1823303-2-patrick.wang.shcn@gmail.comSigned-off-by: Patrick Wang <patrick.wang.shcn@gmail.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Yee Lee <yee.lee@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Miaohe Lin authored
If make_device_exclusive_range() fails or returns pages marked for exclusive access less than required, remaining fields of pages will left uninitialized. So dmirror_atomic_map() will access those yet uninitialized fields of pages. To fix it, do dmirror_atomic_map() iff all pages are marked for exclusive access (we will break if mapped is less than required anyway) so we won't access those uninitialized fields of pages. Link: https://lkml.kernel.org/r/20220609130835.35110-1-linmiaohe@huawei.com Fixes: b659baea ("mm: selftests for exclusive device memory") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Miaohe Lin authored
Fix the wrong function name dev_memremap_pages above memremap_pages() to avoid confusion. Minor readability improvement. Link: https://lkml.kernel.org/r/20220607143621.58989-1-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Daniel Vetter authored
mempool are generally used for GFP_NOIO, so this wont benefit all that much because might_alloc currently only checks GFP_NOFS. But it does validate against mmu notifier pte zapping, some might catch some drivers doing really silly things, plus it's a bit more meaningful in what we're checking for here. Link: https://lkml.kernel.org/r/20220605152539.3196045-3-daniel.vetter@ffwll.chSigned-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Daniel Vetter authored
It only does a might_sleep_if(GFP_RECLAIM) check, which is already covered by the might_alloc() in slab_pre_alloc_hook(). And all callers of cache_alloc_debugcheck_before() call that beforehand already. Link: https://lkml.kernel.org/r/20220605152539.3196045-2-daniel.vetter@ffwll.chSigned-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Daniel Vetter authored
... instead of open coding it. Completely equivalent code, just a notch more meaningful when reading. Link: https://lkml.kernel.org/r/20220605152539.3196045-1-daniel.vetter@ffwll.chSigned-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Fabio M. De Francesco authored
Matthew Wilcox reported that, while he was looking at memmove_page(), he realized that it can't actually work. The reasons are hidden in its implementation, which makes use of memmove() on logical addresses provided by kmap_local_page(). memmove() does the wrong thing when it tests "if (dest <= src)". Therefore, delete memmove_page(). No need to change any other code because we have no call sites of memmove_page() across the whole kernel. Link: https://lkml.kernel.org/r/20220606141533.555-1-fmdefrancesco@gmail.comSigned-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reported-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Qi Zheng authored
There are already statistics of {pgscan,pgsteal}_kswapd and {pgscan,pgsteal}_direct of memcg event here, but now only the sum of the two is displayed in memory.stat of cgroup v2. In order to obtain more accurate information during monitoring and debugging, and to align with the display in /proc/vmstat, it better to display {pgscan,pgsteal}_kswapd and {pgscan,pgsteal}_direct separately. Also, for forward compatibility, we still display pgscan and pgsteal items so that it won't break existing applications. [zhengqi.arch@bytedance.com: add comment for memcg_vm_event_stat (suggested by Michal)] Link: https://lkml.kernel.org/r/20220606154028.55030-1-zhengqi.arch@bytedance.com [zhengqi.arch@bytedance.com: fix the doc, thanks to Johannes] Link: https://lkml.kernel.org/r/20220607064803.79363-1-zhengqi.arch@bytedance.com Link: https://lkml.kernel.org/r/20220604082209.55174-1-zhengqi.arch@bytedance.comSigned-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Baoquan He authored
Its behaviour is like find_vma() which finds an area above the specified address, add comment to make it easier to understand. And also fix two places of grammer mistake/typo. Link: https://lkml.kernel.org/r/20220607105958.382076-5-bhe@redhat.comSigned-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Baoquan He authored
In __purge_vmap_area_lazy(), rename local_pure_list to local_purge_list. Link: https://lkml.kernel.org/r/20220607105958.382076-4-bhe@redhat.comSigned-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Baoquan He authored
In find_va_links(), when traversing the vmap_area tree, the comparing to check if the passed in 'va' is above or below 'tmp_va' is redundant, assuming both 'va' and 'tmp_va' has ->va_start <= ->va_end. Here, to simplify the checking as code change. Link: https://lkml.kernel.org/r/20220607105958.382076-3-bhe@redhat.comSigned-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Baoquan He authored
Patch series "Cleanup patches of vmalloc", v2. Some cleanup patches found when reading vmalloc code. This patch (of 4): adjust_va_to_fit_type() checks all values of passed in fit type, including NOTHING_FIT in the else branch. However, the check of NOTHING_FIT has been done inside adjust_va_to_fit_type() and before it's called in all call sites. In fact, both of these functions are coupled tightly, since classify_va_fit_type() is doing the preparation work for adjust_va_to_fit_type(). So putting invocation of classify_va_fit_type() inside adjust_va_to_fit_type() can simplify code logic and the redundant check of NOTHING_FIT issue will go away. Link: https://lkml.kernel.org/r/20220607105958.382076-1-bhe@redhat.com Link: https://lkml.kernel.org/r/20220607105958.382076-2-bhe@redhat.comSigned-off-by: Baoquan He <bhe@redhat.com> Suggested-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Chengming Zhou authored
Since commit 0f91d133 ("mm/damon: simplify stop mechanism") delete kdamond_stop and change to use kthread stop mechanism, these obsolete comments should be removed accordingly. Link: https://lkml.kernel.org/r/20220531020421.46849-1-zhouchengming@bytedance.comSigned-off-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Anshuman Khandual authored
In check_pfn_span(), a 'reason' string is being used to recreate the caller function name, while printing the warning message. It is really unnecessary as the warning message could just be printed inside the caller depending on the return code. Currently there are just two callers for check_pfn_span() i.e __add_pages() and __remove_pages(). Let's clean this up. Link: https://lkml.kernel.org/r/20220531090441.170650-1-anshuman.khandual@arm.comSigned-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Miaohe Lin authored
shmem_swapin_folio has changed to use folio but comment still mentions page. Update the relevant comment accordingly as suggested by Naoya. Link: https://lkml.kernel.org/r/20220530115841.4348-1-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com> Suggested-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Peter Xu authored
I observed that for each of the shared file-backed page faults, we're very likely to retry one more time for the 1st write fault upon no page. It's because we'll need to release the mmap lock for dirty rate limit purpose with balance_dirty_pages_ratelimited() (in fault_dirty_shared_page()). Then after that throttling we return VM_FAULT_RETRY. We did that probably because VM_FAULT_RETRY is the only way we can return to the fault handler at that time telling it we've released the mmap lock. However that's not ideal because it's very likely the fault does not need to be retried at all since the pgtable was well installed before the throttling, so the next continuous fault (including taking mmap read lock, walk the pgtable, etc.) could be in most cases unnecessary. It's not only slowing down page faults for shared file-backed, but also add more mmap lock contention which is in most cases not needed at all. To observe this, one could try to write to some shmem page and look at "pgfault" value in /proc/vmstat, then we should expect 2 counts for each shmem write simply because we retried, and vm event "pgfault" will capture that. To make it more efficient, add a new VM_FAULT_COMPLETED return code just to show that we've completed the whole fault and released the lock. It's also a hint that we should very possibly not need another fault immediately on this page because we've just completed it. This patch provides a ~12% perf boost on my aarch64 test VM with a simple program sequentially dirtying 400MB shmem file being mmap()ed and these are the time it needs: Before: 650.980 ms (+-1.94%) After: 569.396 ms (+-1.38%) I believe it could help more than that. We need some special care on GUP and the s390 pgfault handler (for gmap code before returning from pgfault), the rest changes in the page fault handlers should be relatively straightforward. Another thing to mention is that mm_account_fault() does take this new fault as a generic fault to be accounted, unlike VM_FAULT_RETRY. I explicitly didn't touch hmm_vma_fault() and break_ksm() because they do not handle VM_FAULT_RETRY even with existing code, so I'm literally keeping them as-is. Link: https://lkml.kernel.org/r/20220530183450.42886-1-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vineet Gupta <vgupta@kernel.org> Acked-by: Guo Ren <guoren@kernel.org> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm part] Acked-by: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Stafford Horne <shorne@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Brian Cain <bcain@quicinc.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Richard Weinberger <richard@nod.at> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Will Deacon <will@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Simek <monstr@monstr.eu> Cc: Matt Turner <mattst88@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: David Hildenbrand <david@redhat.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Chris Zankel <chris@zankel.net> Cc: Hugh Dickins <hughd@google.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Rich Felker <dalias@libc.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Helge Deller <deller@gmx.de> Cc: Yoshinori Sato <ysato@users.osdn.me> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Yuanzheng Song authored
When the number of partial slabs in each cache is the same (e.g., the value are 0), the results of the `slabinfo -X -N5` and `slabinfo -P -N5` are different. / # slabinfo -X -N5 ... Slabs sorted by number of partial slabs --------------------------------------- Name Objects Objsize Space Slabs/Part/Cpu O/S O %Fr %Ef Flg inode_cache 15180 392 6217728b 758/0/1 20 1 0 95 a kernfs_node_cache 22494 88 2002944 488/0/1 46 0 0 98 shmem_inode_cache 663 464 319488 38/0/1 17 1 0 96 biovec-max 50 3072 163840 4/0/1 10 3 0 93 A dentry 19050 136 2600960 633/0/2 30 0 0 99 a / # slabinfo -P -N5 Name Objects Objsize Space Slabs/Part/Cpu O/S O %Fr %Ef Flg bdev_cache 32 984 32.7K 1/0/1 16 2 0 96 Aa ext4_inode_cache 42 752 32.7K 1/0/1 21 2 0 96 a dentry 19050 136 2.6M 633/0/2 30 0 0 99 a TCPv6 17 1840 32.7K 0/0/1 17 3 0 95 A RAWv6 18 856 16.3K 0/0/1 18 2 0 94 A This problem is caused by the sort_slabs(). So let's use alphabetic order when two values are equal in the sort_slabs(). By the way, the content of the `slabinfo -h` is not aligned because the `-P|--partial Sort by number of partial slabs` uses tabs instead of spaces. So let's use spaces instead of tabs to fix it. Link: https://lkml.kernel.org/r/20220528063117.935158-1-songyuanzheng@huawei.com Fixes: 1106b205 ("tools/vm/slabinfo: add partial slab listing to -X") Signed-off-by: Yuanzheng Song <songyuanzheng@huawei.com> Cc: "Tobin C. Harding" <tobin@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Fanjun Kong authored
<linux/mm.h> already provides the PAGE_ALIGNED macro. Let's use this macro instead of IS_ALIGNED and passing PAGE_SIZE directly. Link: https://lkml.kernel.org/r/20220526140257.1568744-1-bh1scw@gmail.comSigned-off-by: Fanjun Kong <bh1scw@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Peter Xu authored
It seems to exist since the old times and never used once. Remove them. Link: https://lkml.kernel.org/r/20220525195220.10241-1-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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- 12 Jun, 2022 10 commits
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Linus Torvalds authored
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Linus Torvalds authored
Merge tag 'platform-drivers-x86-v5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86 Pull x86 platform driver fixes from Hans de Goede: "Highlights: - Fix hp-wmi regression on HP Omen laptops introduced in 5.18 - Several hardware-id additions - A couple of other tiny fixes" * tag 'platform-drivers-x86-v5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: platform/x86/intel: hid: Add Surface Go to VGBS allow list platform/x86: hp-wmi: Use zero insize parameter only when supported platform/x86: hp-wmi: Resolve WMI query failures on some devices platform/x86: gigabyte-wmi: Add support for B450M DS3H-CF platform/x86: gigabyte-wmi: Add Z690M AORUS ELITE AX DDR4 support platform/x86: barco-p50-gpio: Add check for platform_driver_register platform/x86/intel: pmc: Support Intel Raptorlake P platform/x86/intel: Fix pmt_crashlog array reference platform/mellanox: Add static in struct declaration. platform/mellanox: Spelling s/platfom/platform/
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds authored
Pull workqueue fixes from Tejun Heo: "Tetsuo's patch to trigger build warnings if system-wide wq's are flushed along with a TP type update and trivial comment update" * tag 'wq-for-5.19-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Switch to new kerneldoc syntax for named variable macro argument workqueue: Fix type of cpu in trace event workqueue: Wrap flush_workqueue() using a macro
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Linus Torvalds authored
Merge tag 'kbuild-fixes-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - Make the *.mod build rule portable for POSIX awk - Fix regression of 'make nsdeps' - Make scripts/check-local-export working for older bash versions - Fix scripts/gdb to extract the .config data from vmlinux * tag 'kbuild-fixes-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: scripts/gdb: change kernel config dumping method scripts/check-local-export: avoid 'wait $!' for process substitution scripts/nsdeps: adjust to the format change of *.mod files kbuild: avoid regex RS for POSIX awk
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git://git.samba.org/sfrench/cifs-2.6Linus Torvalds authored
Pull cifs client fixes from Steve French: "Three reconnect fixes, all for stable as well. One of these three reconnect fixes does address a problem with multichannel reconnect, but this does not include the additional fix (still being tested) for dynamically detecting multichannel adapter changes which will improve those reconnect scenarios even more" * tag '5.19-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: populate empty hostnames for extra channels cifs: return errors during session setup during reconnects cifs: fix reconnect on smb3 mount types
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git://git.kernel.org/pub/scm/linux/kernel/git/crng/randomLinus Torvalds authored
Pull random number generator fixes from Jason Donenfeld: - A fix for a 5.19 regression for a case in which early device tree initializes the RNG, which flips a static branch. On most plaforms, jump labels aren't initialized until much later, so this caused splats. On a few mailing list threads, we cooked up easy fixes for arm64, arm32, and risc-v. But then things looked slightly more involved for xtensa, powerpc, arc, and mips. And at that point, when we're patching 7 architectures in a place before the console is even available, it seems like the cost/risk just wasn't worth it. So random.c works around it now by checking the already exported `static_key_initialized` boolean, as though somebody already ran into this issue in the past. I'm not super jazzed about that; it'd be prettier to not have to complicate downstream code. But I suppose it's practical. - A few small code nits and adding a missing __init annotation. - A change to the default config values to use the cpu and bootloader's seeds for initializing the RNG earlier. This brings them into line with what all the distros do (Fedora/RHEL, Debian, Ubuntu, Gentoo, Arch, NixOS, Alpine, SUSE, and Void... at least), and moreover will now give us test coverage in various test beds that might have caught the above device tree bug earlier. - A change to WireGuard CI's configuration to increase test coverage around the RNG. - A documentation comment fix to unrelated maintainerless CRC code that I was asked to take, I guess because it has to do with polynomials (which the RNG thankfully no longer uses). * tag 'random-5.19-rc2-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: wireguard: selftests: use maximum cpu features and allow rng seeding random: remove rng_has_arch_random() random: credit cpu and bootloader seeds by default random: do not use jump labels before they are initialized random: account for arch randomness in bits random: mark bootloader randomness code as __init random: avoid checking crng_ready() twice in random_init() crc-itu-t: fix typo in CRC ITU-T polynomial comment
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Duke Lee authored
The Surface Go reports Chassis Type 9 (Laptop,) so the device needs to be added to dmi_vgbs_allow_list to enable tablet mode when an attached Type Cover is folded back. BugLink: https://github.com/linux-surface/linux-surface/issues/837Signed-off-by: Duke Lee <krnhotwings@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20220607213654.5567-1-krnhotwings@gmail.comReviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
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Bedant Patnaik authored
commit be9d73e6 ("platform/x86: hp-wmi: Fix 0x05 error code reported by several WMI calls") and commit 12b19f14 ("platform/x86: hp-wmi: Fix hp_wmi_read_int() reporting error (0x05)") cause ACPI BIOS Error (bug): Attempt to CreateField of length zero (20211217/dsopcode-133) because of the ACPI method HWMC, which unconditionally creates a Field of size (insize*8) bits: CreateField (Arg1, 0x80, (Local5 * 0x08), DAIN) In cases where args->insize = 0, the Field size is 0, resulting in an error. Fix this by using zero insize only if 0x5 error code is returned Tested on Omen 15 AMD (2020) board ID: 8786. Fixes: be9d73e6 ("platform/x86: hp-wmi: Fix 0x05 error code reported by several WMI calls") Signed-off-by: Bedant Patnaik <bedant.patnaik@gmail.com> Tested-by: Jorge Lopez <jorge.lopez2@hp.com> Link: https://lore.kernel.org/r/41be46743d21c78741232a47bbb5f1cdbcc3d21e.camel@gmail.comReviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
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Jorge Lopez authored
WMI queries fail on some devices where the ACPI method HWMC unconditionally attempts to create Fields beyond the buffer if the buffer is too small, this breaks essential features such as power profiles: CreateByteField (Arg1, 0x10, D008) CreateByteField (Arg1, 0x11, D009) CreateByteField (Arg1, 0x12, D010) CreateDWordField (Arg1, 0x10, D032) CreateField (Arg1, 0x80, 0x0400, D128) In cases where args->data had zero length, ACPI BIOS Error (bug): AE_AML_BUFFER_LIMIT, Field [D008] at bit offset/length 128/8 exceeds size of target Buffer (128 bits) (20211217/dsopcode-198) was obtained. ACPI BIOS Error (bug): AE_AML_BUFFER_LIMIT, Field [D009] at bit offset/length 136/8 exceeds size of target Buffer (136bits) (20211217/dsopcode-198) The original code created a buffer size of 128 bytes regardless if the WMI call required a smaller buffer or not. This particular behavior occurs in older BIOS and reproduced in OMEN laptops. Newer BIOS handles buffer sizes properly and meets the latest specification requirements. This is the reason why testing with a dynamically allocated buffer did not uncover any failures with the test systems at hand. This patch was tested on several OMEN, Elite, and Zbooks. It was confirmed the patch resolves HPWMI_FAN GET/SET calls in an OMEN Laptop 15-ek0xxx. No problems were reported when testing on several Elite and Zbooks notebooks. Fixes: 4b4967cb ("platform/x86: hp-wmi: Changing bios_args.data to be dynamically allocated") Signed-off-by: Jorge Lopez <jorge.lopez2@hp.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20220608212923.8585-2-jorge.lopez2@hp.comReviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
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Jonathan Neuschäfer authored
The syntax without dots is available since commit 43756e34 ("scripts/kernel-doc: Add support for named variable macro arguments"). The same HTML output is produced with and without this patch. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
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