- 06 Nov, 2015 40 commits
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Catalin Marinas authored
On systems with a KMALLOC_MIN_SIZE of 128 (arm64, some mips and powerpc configurations defining ARCH_DMA_MINALIGN to 128), the first kmalloc_caches[] entry to be initialised after slab_early_init = 0 is "kmalloc-128" with index 7. Depending on the debug kernel configuration, sizeof(struct kmem_cache) can be larger than 128 resulting in an INDEX_NODE of 8. Commit 8fc9cf42 ("slab: make more slab management structure off the slab") enables off-slab management objects for sizes starting with PAGE_SIZE >> 5 (128 bytes for a 4KB page configuration) and the creation of the "kmalloc-128" cache would try to place the management objects off-slab. However, since KMALLOC_MIN_SIZE is already 128 and freelist_size == 32 in __kmem_cache_create(), kmalloc_slab(freelist_size) returns NULL (kmalloc_caches[7] not populated yet). This triggers the following bug on arm64: kernel BUG at /work/Linux/linux-2.6-aarch64/mm/slab.c:2283! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.3.0-rc4+ #540 Hardware name: Juno (DT) PC is at __kmem_cache_create+0x21c/0x280 LR is at __kmem_cache_create+0x210/0x280 [...] Call trace: __kmem_cache_create+0x21c/0x280 create_boot_cache+0x48/0x80 create_kmalloc_cache+0x50/0x88 create_kmalloc_caches+0x4c/0xf4 kmem_cache_init+0x100/0x118 start_kernel+0x214/0x33c This patch introduces an OFF_SLAB_MIN_SIZE definition to avoid off-slab management objects for sizes equal to or smaller than KMALLOC_MIN_SIZE. Fixes: 8fc9cf42 ("slab: make more slab management structure off the slab") Signed-off-by:
Catalin Marinas <catalin.marinas@arm.com> Reported-by:
Geert Uytterhoeven <geert@linux-m68k.org> Acked-by:
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: <stable@vger.kernel.org> [3.15+] Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Wei Yang authored
In slub_order(), the order starts from max(min_order, get_order(min_objects * size)). When (min_objects * size) has different order from (min_objects * size + reserved), it will skip this order via a check in the loop. This patch optimizes this a little by calculating the start order with `reserved' in consideration and removing the check in loop. Signed-off-by:
Wei Yang <weiyang@linux.vnet.ibm.com> Acked-by:
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Wei Yang authored
get_order() is more easy to understand. This patch just replaces it. Signed-off-by:
Pekka Enberg <penberg@kernel.org> Signed-off-by:
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Wei Yang authored
In calculate_order(), it tries to calculate the best order by adjusting the fraction and min_objects. On each iteration on min_objects, fraction iterates on 16, 8, 4. Which means the acceptable waste increases with 1/16, 1/8, 1/4. This patch corrects the comment according to the code. Signed-off-by:
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Alexandru Moise authored
The assignment to NULL within the error condition was written in a 2014 patch to suppress a compiler warning. However it would be cleaner to just initialize the kmem_cache to NULL and just return it in case of an error condition. Signed-off-by:
Alexandru Moise <00moses.alexander00@gmail.com> Acked-by:
David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
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Sergey Senozhatsky authored
Add documentation on how to use slabinfo-gnuplot.sh script. Signed-off-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by:
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Sergey Senozhatsky authored
GNUplot `slabinfo -X' stats, collected, for example, using the following command: while [ 1 ]; do slabinfo -X >> stats; sleep 1; done `slabinfo-gnuplot.sh stats' pre-processes collected records and generate graphs (totals, slabs sorted by size, slabs sorted by size). Graphs can be [individually] regenerate with different samples range and graph width-heigh (-r %d,%d and -s %d,%d options). To visually compare N `totals' graphs: slabinfo-gnuplot.sh -t FILE1-totals FILE2-totals ... FILEN-totals Signed-off-by:
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Sergey Senozhatsky authored
checkpatch.pl complains about globals being explicitly zeroed out: "ERROR: do not initialise globals to 0 or NULL". New globals, introduced in this patch set, have no explicit 0 initialization; clean up the old ones to make it less hairy. Signed-off-by:
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Sergey Senozhatsky authored
Introduce "-B|--Bytes" opt to disable store_size() dynamic size scaling and report size in bytes instead. This `expands' the interface a bit, it's impossible to use printf("%6s") anymore to output sizes. Example: slabinfo -X -N 2 Slabcache Totals ---------------- Slabcaches : 91 Aliases : 119->69 Active: 63 Memory used: 199798784 # Loss : 10689376 MRatio: 5% # Objects : 324301 # PartObj: 18151 ORatio: 5% Per Cache Average Min Max Total ---------------------------------------------------------------------------- #Objects 5147 1 89068 324301 #Slabs 199 1 3886 12537 #PartSlab 12 0 240 778 %PartSlab 32% 0% 100% 6% PartObjs 5 0 4569 18151 % PartObj 26% 0% 100% 5% Memory 3171409 8192 127336448 199798784 Used 3001736 160 121429728 189109408 Loss 169672 0 5906720 10689376 Per Object Average Min Max ----------------------------------------------------------- Memory 585 8 8192 User 583 8 8192 Loss 2 0 64 Slabs sorted by size -------------------- Name Objects Objsize Space Slabs/Part/Cpu O/S O %Fr %Ef Flg ext4_inode_cache 69948 1736 127336448 3871/0/15 18 3 0 95 a dentry 89068 288 26058752 3164/0/17 28 1 0 98 a Slabs sorted by loss -------------------- Name Objects Objsize Loss Slabs/Part/Cpu O/S O %Fr %Ef Flg ext4_inode_cache 69948 1736 5906720 3871/0/15 18 3 0 95 a inode_cache 11628 864 537472 642/0/4 18 2 0 94 a Besides, store_size() does not use powers of two for G/M/K if (value > 1000000000UL) { divisor = 100000000UL; trailer = 'G'; } else if (value > 1000000UL) { divisor = 100000UL; trailer = 'M'; } else if (value > 1000UL) { divisor = 100; trailer = 'K'; } Signed-off-by: -
Sergey Senozhatsky authored
Add "-X|--Xtotals" opt to output extended totals summary, which includes: -- totals summary -- slabs sorted by size -- slabs sorted by loss (waste) Example: ======= slabinfo --X -N 1 Slabcache Totals ---------------- Slabcaches : 91 Aliases : 120->69 Active: 65 Memory used: 568.3M # Loss : 30.4M MRatio: 5% # Objects : 920.1K # PartObj: 161.2K ORatio: 17% Per Cache Average Min Max Total --------------------------------------------------------- #Objects 14.1K 1 227.8K 920.1K #Slabs 533 1 11.7K 34.7K #PartSlab 86 0 4.3K 5.6K %PartSlab 24% 0% 100% 16% PartObjs 17 0 129.3K 161.2K % PartObj 17% 0% 100% 17% Memory 8.7M 8.1K 384.7M 568.3M Used 8.2M 160 366.5M 537.9M Loss 468.8K 0 18.2M 30.4M Per Object Average Min Max --------------------------------------------- Memory 587 8 8.1K User 584 8 8.1K Loss 2 0 64 Slabs sorted by size ---------------------- Name Objects Objsize Space Slabs/Part/Cpu O/S O %Fr %Ef Flg ext4_inode_cache 211142 1736 384.7M 11732/40/10 18 3 0 95 a Slabs sorted by loss ---------------------- Name Objects Objsize Loss Slabs/Part/Cpu O/S O %Fr %Ef Flg ext4_inode_cache 211142 1736 18.2M 11732/40/10 18 3 0 95 a Signed-off-by:
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Sergey Senozhatsky authored
Fix mismatches between usage() output and real opts[] options. Add missing alternative opt names, e.g., '-S' had no '--Size' opts[] entry, etc. Signed-off-by:
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Sergey Senozhatsky authored
Introduce opt "-L|--sort-loss" to sort and output slabs by loss (waste) in slabcache(). Signed-off-by:
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Sergey Senozhatsky authored
Introduce opt "-N|--lines=K" to limit the number of slabs being reported in output_slabs(). Signed-off-by:
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Sergey Senozhatsky authored
This patchset adds 'extended' slabinfo mode that provides additional information: -- totals summary -- slabs sorted by size -- slabs sorted by loss (waste) The patches also introduces several new slabinfo options to limit the number of slabs reported, sort slabs by loss (waste); and some fixes. Extended output example (slabinfo -X -N 2): Slabcache Totals ---------------- Slabcaches : 91 Aliases : 119->69 Active: 63 Memory used: 199798784 # Loss : 10689376 MRatio: 5% # Objects : 324301 # PartObj: 18151 ORatio: 5% Per Cache Average Min Max Total ---------------------------------------------------------------------------- #Objects 5147 1 89068 324301 #Slabs 199 1 3886 12537 #PartSlab 12 0 240 778 %PartSlab 32% 0% 100% 6% PartObjs 5 0 4569 18151 % PartObj 26% 0% 100% 5% Memory 3171409 8192 127336448 199798784 Used 3001736 160 121429728 189109408 Loss 169672 0 5906720 10689376 Per Object Average Min Max ----------------------------------------------------------- Memory 585 8 8192 User 583 8 8192 Loss 2 0 64 Slabs sorted by size -------------------- Name Objects Objsize Space Slabs/Part/Cpu O/S O %Fr %Ef Flg ext4_inode_cache 69948 1736 127336448 3871/0/15 18 3 0 95 a dentry 89068 288 26058752 3164/0/17 28 1 0 98 a Slabs sorted by loss -------------------- Name Objects Objsize Loss Slabs/Part/Cpu O/S O %Fr %Ef Flg ext4_inode_cache 69948 1736 5906720 3871/0/15 18 3 0 95 a inode_cache 11628 864 537472 642/0/4 18 2 0 94 a The last patch in the series addresses Linus' comment from http://marc.info/?l=linux-mm&m=144148518703321&w=2 (well, it's been some time. sorry.) gnuplot script takes the slabinfo records file, where every record is a `slabinfo -X' output. So the basic workflow is, for example, as follows: while [ 1 ]; do slabinfo -X -N 2 >> stats; sleep 1; done ^C slabinfo-gnuplot.sh stats The last command will produce 3 png files (and 3 stats files) -- graph of slabinfo totals -- graph of slabs by size -- graph of slabs by loss It's also possible to select a range of records for plotting (a range of collected slabinfo outputs) via `-r 10,100` (for example); and compare totals from several measurements (to visially compare slabs behaviour (10,50 range)) using pre-parsed totals files: slabinfo-gnuplot.sh -r 10,50 -t stats-totals1 .. stats-totals2 This also, technically, supports ktest. Upload new slabinfo to target, collect the stats and give the resulting stats file to slabinfo-gnuplot This patch (of 8): Use getopt constants in `struct option' ->has_arg instead of numerical representations. Signed-off-by:
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Vladimir Davydov authored
Currently, when kmem_cache_destroy() is called for a global cache, we print a warning for each per memcg cache attached to it that has active objects (see shutdown_cache). This is redundant, because it gives no new information and only clutters the log. If a cache being destroyed has active objects, there must be a memory leak in the module that created the cache, and it does not matter if the cache was used by users in memory cgroups or not. This patch moves the warning from shutdown_cache(), which is called for shutting down both global and per memcg caches, to kmem_cache_destroy(), so that the warning is only printed once if there are objects left in the cache being destroyed. Signed-off-by:
Vladimir Davydov <vdavydov@virtuozzo.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> Signed-off-by:
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Vladimir Davydov authored
Currently, we do not clear pointers to per memcg caches in the memcg_params.memcg_caches array when a global cache is destroyed with kmem_cache_destroy. This is fine if the global cache does get destroyed. However, a cache can be left on the list if it still has active objects when kmem_cache_destroy is called (due to a memory leak). If this happens, the entries in the array will point to already freed areas, which is likely to result in data corruption when the cache is reused (via slab merging). Signed-off-by:
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Vladimir Davydov authored
do_kmem_cache_create(), do_kmem_cache_shutdown(), and do_kmem_cache_release() sound awkward for static helper functions that are not supposed to be used outside slab_common.c. Rename them to create_cache(), shutdown_cache(), and release_caches(), respectively. This patch is a pure cleanup and does not introduce any functional changes. Signed-off-by:
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Rasmus Villemoes authored
The patch "slab.h: sprinkle __assume_aligned attributes" causes *tons* of whinges if you do 'make C=2' with sparse 0.5.0: CHECK drivers/media/usb/pwc/pwc-if.c include/linux/slab.h:307:43: error: attribute '__assume_aligned__': unknown attribute include/linux/slab.h:308:58: error: attribute '__assume_aligned__': unknown attribute include/linux/slab.h:337:73: error: attribute '__assume_aligned__': unknown attribute include/linux/slab.h:375:74: error: attribute '__assume_aligned__': unknown attribute include/linux/slab.h:378:80: error: attribute '__assume_aligned__': unknown attribute sparse apparently pretends to be gcc >= 4.9, yet isn't prepared to handle all the function attributes supported by those gccs and complains loudly. So hide the definition of __assume_aligned from it (so that the generic one in compiler.h gets used). Signed-off-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Reported-by:
Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Tested-By:
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Rasmus Villemoes authored
gcc 4.9 added the function attribute assume_aligned, indicating to the caller that the returned pointer may be assumed to have a certain minimal alignment. This is useful if, for example, the return value is passed to memset(). Add a shorthand macro for that. Signed-off-by:
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Denis Kirjanov authored
A good candidate to return a boolean result. Signed-off-by:
Denis Kirjanov <kda@linux-powerpc.org> Cc: Christoph Lameter <cl@linux.com> Reviewed-by:
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Ulrich Obergfell authored
Theoretically it is possible that the watchdog timer expires right at the time when a user sets 'watchdog_thresh' to zero (note: this disables the lockup detectors). In this scenario, the is_softlockup() function - which is called by the timer - could produce a false positive. Fix this by checking the current value of 'watchdog_thresh'. Signed-off-by:
Ulrich Obergfell <uobergfe@redhat.com> Acked-by:
Don Zickus <dzickus@redhat.com> Reviewed-by:
Aaron Tomlin <atomlin@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by:
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Ulrich Obergfell authored
watchdog_{park|unpark}_threads() are now called in code paths that protect themselves against CPU hotplug, so {get|put}_online_cpus() calls are redundant and can be removed. Signed-off-by: -
Ulrich Obergfell authored
The handler functions for watchdog parameters in /proc/sys/kernel do not protect themselves against races with CPU hotplug. Hence, theoretically it is possible that a new watchdog thread is started on a hotplugged CPU while a parameter is being modified, and the thread could thus use a parameter value that is 'in transition'. For example, if 'watchdog_thresh' is being set to zero (note: this disables the lockup detectors) the thread would erroneously use the value zero as the sample period. To avoid such races and to keep the /proc handler code consistent, call {get|put}_online_cpus() in proc_watchdog_common() {get|put}_online_cpus() in proc_watchdog_thresh() {get|put}_online_cpus() in proc_watchdog_cpumask() Signed-off-by: -
Ulrich Obergfell authored
The lockup detector suspend/resume interface that was introduced by commit 8c073d27 ("watchdog: introduce watchdog_suspend() and watchdog_resume()") does not protect itself against races with CPU hotplug. Hence, theoretically it is possible that a new watchdog thread is started on a hotplugged CPU while the lockup detector is suspended, and the thread could thus interfere unexpectedly with the code that requested to suspend the lockup detector. Avoid the race by calling get_online_cpus() in lockup_detector_suspend() put_online_cpus() in lockup_detector_resume() Signed-off-by:
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Don Zickus authored
The only way to enable a hardlockup to panic the machine is to set 'nmi_watchdog=panic' on the kernel command line. This makes it awkward for end users and folks who want to run automate tests (like myself). Mimic the softlockup_panic knob and create a /proc/sys/kernel/hardlockup_panic knob. Signed-off-by:
Jiri Kosina <jkosina@suse.cz> Reviewed-by:
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Jiri Kosina authored
In many cases of hardlockup reports, it's actually not possible to know why it triggered, because the CPU that got stuck is usually waiting on a resource (with IRQs disabled) in posession of some other CPU is holding. IOW, we are often looking at the stacktrace of the victim and not the actual offender. Introduce sysctl / cmdline parameter that makes it possible to have hardlockup detector perform all-CPU backtrace. Signed-off-by:
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Ulrich Obergfell authored
If kthread_park() returns an error, watchdog_park_threads() should not blindly 'roll back' the already parked threads to the unparked state. Instead leave it up to the callers to handle such errors appropriately in their context. For example, it is redundant to unpark the threads if the lockup detectors will soon be disabled by the callers anyway. Signed-off-by:
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Ulrich Obergfell authored
lockup_detector_suspend() now handles errors from watchdog_park_threads(). Signed-off-by:
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Ulrich Obergfell authored
update_watchdog_all_cpus() now passes errors from watchdog_park_threads() up to functions in the call chain. This allows watchdog_enable_all_cpus() and proc_watchdog_update() to handle such errors too. Signed-off-by:
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Ulrich Obergfell authored
Move watchdog_disable_all_cpus() outside of the ifdef so that it is available if CONFIG_SYSCTL is not defined. This is preparation for "watchdog: implement error handling in update_watchdog_all_cpus() and callers". Signed-off-by:
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Ulrich Obergfell authored
The original watchdog_park_threads() function that was introduced by commit 81a4beef ("watchdog: introduce watchdog_park_threads() and watchdog_unpark_threads()") takes a very simple approach to handle errors returned by kthread_park(): It attempts to roll back all watchdog threads to the unparked state. However, this may be undesired behaviour from the perspective of the caller which may want to handle errors as appropriate in its specific context. Currently, there are two possible call chains: - watchdog suspend/resume interface lockup_detector_suspend watchdog_park_threads - write to parameters in /proc/sys/kernel proc_watchdog_update watchdog_enable_all_cpus update_watchdog_all_cpus watchdog_park_threads Instead of 'blindly' attempting to unpark the watchdog threads if a kthread_park() call fails, the new approach is to disable the lockup detectors in the above call chains. Failure becomes visible to the user as follows: - error messages from lockup_detector_suspend() or watchdog_enable_all_cpus() - the state that can be read from /proc/sys/kernel/watchdog_enabled - the 'write' system call in the latter call chain returns an error I did not experience kthread_park() failures in practice, I used some instrumentation to fake error returns from kthread_park() in order to test the patches. This patch (of 5): Restore the previous value of watchdog_thresh _and_ sample_period if proc_watchdog_update() returns an error. The variables must be consistent to avoid false positives of the lockup detectors. Signed-off-by:
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Yaowei Bai authored
Make is_hardlockup return bool to improve readability due to this particular function only using either one or zero as its return value. No functional change. Signed-off-by:
Yaowei Bai <bywxiaobai@163.com> Reviewed-by:
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Dominique Martinet authored
If the remote locking fail, we run a local vfs unlock that should work and return success to userland when we didn't actually lock at all. We need to tell the application that tried to lock that it didn't get it, not that all went well. Signed-off-by:
Dominique Martinet <dominique.martinet@cea.fr> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by:
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Kirill A. Shutemov authored
Make struct callback_head aligned to size of pointer. On most architectures it happens naturally due ABI requirements, but some architectures (like CRIS) have weird ABI and we need to ask it explicitly. The alignment is required to guarantee that bits 0 and 1 of @next will be clear under normal conditions -- as long as we use call_rcu(), call_rcu_bh(), call_rcu_sched(), or call_srcu() to queue callback. This guarantee is important for few reasons: - future call_rcu_lazy() will make use of lower bits in the pointer; - the structure shares storage spacer in struct page with @compound_head, which encode PageTail() in bit 0. The guarantee is needed to avoid false-positive PageTail(). False postive PageTail() caused crash on crisv32[1]. It happend due misaligned task_struct->rcu, which was byte-aligned. [1] http://lkml.kernel.org/r/55FAEA67.9000102@roeck-us.netSigned-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by:
Guenter Roeck <linux@roeck-us.net> Tested-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by:
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Joseph Qi authored
readahead_pages in ocfs2_duplicate_clusters_by_page is defined but not used, so clean it up. Signed-off-by:
Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by:
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Joseph Qi authored
A node can mount multiple ocfs2 volumes. And if thread names are same for each volume/domain, it will bring inconvenience when analyzing problems because we have to identify which volume/domain the messages belong to. Since thread name will be printed to messages, so add volume uuid or dlm name to thread name can benefit problem analysis. Signed-off-by:
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alex chen authored
In ocfs2_mknod_locked if '__ocfs2_mknod_locke d' returns an error, we should reclaim the inode successfully claimed above, otherwise, the inode never be reused. The case is described below: ocfs2_mknod ocfs2_mknod_locked ocfs2_claim_new_inode Successfully claim the inode __ocfs2_mknod_locked ocfs2_journal_access_di Failed because of -ENOMEM or other reasons, the inode lockres has not been initialized yet. iput(inode) ocfs2_evict_inode ocfs2_delete_inode ocfs2_inode_lock ocfs2_inode_lock_full_nested __ocfs2_cluster_lock Return -EINVAL because of the inode lockres has not been initialized. So the following operations are not performed ocfs2_wipe_inode ocfs2_remove_inode ocfs2_free_dinode ocfs2_free_suballoc_bits Signed-off-by:Alex Chen <alex.chen@huawei.com> Reviewed-by:
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Joseph Qi authored
There is a race case between mount and delete node/cluster, which will lead o2hb_thread to malfunctioning dead loop. o2hb_thread { o2nm_depend_this_node(); <<<<<< race window, node may have already been deleted, and then enter the loop, o2hb thread will be malfunctioning because of no configured nodes found. while (!kthread_should_stop() && !reg->hr_unclean_stop && !reg->hr_aborted_start) { } So check the return value of o2nm_depend_this_node() is needed. If node has been deleted, do not enter the loop and let mount fail. Signed-off-by: -
Joseph Qi authored
We have no need to take inode mutex, rw and inode lock if it is not dio entry when recover orphans. Optimize it by adding a flag OCFS2_INODE_DIO_ORPHAN_ENTRY to ocfs2_inode_info to reduce contention. Signed-off-by:
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Joseph Qi authored
dio entry will only do truncate in case of ORPHAN_NEED_TRUNCATE. So do not include it when doing normal orphan scan to reduce contention. Signed-off-by:
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