- 11 Dec, 2014 40 commits
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Vlastimil Babka authored
The goal of memory compaction is to create high-order freepages through page migration. Page migration however puts pages on the per-cpu lru_add cache, which is later flushed to per-cpu pcplists, and only after pcplists are drained the pages can actually merge. This can happen due to the per-cpu caches becoming full through further freeing, or explicitly. During direct compaction, it is useful to do the draining explicitly so that pages merge as soon as possible and compaction can detect success immediately and keep the latency impact at minimum. However the current implementation is far from ideal. Draining is done only in __alloc_pages_direct_compact(), after all zones were already compacted, and the decisions to continue or stop compaction in individual zones was done without the last batch of migrations being merged. It is also missing the draining of lru_add cache before the pcplists. This patch moves the draining for direct compaction into compact_zone(). It adds the missing lru_cache draining and uses the newly introduced single zone pcplists draining to reduce overhead and avoid impact on unrelated zones. Draining is only performed when it can actually lead to merging of a page of desired order (passed by cc->order). This means it is only done when migration occurred in the previously scanned cc->order aligned block(s) and the migration scanner is now pointing to the next cc->order aligned block. The patch has been tested with stress-highalloc benchmark from mmtests. Although overal allocation success rates of the benchmark were not affected, the number of detected compaction successes has doubled. This suggests that allocations were previously successful due to implicit merging caused by background activity, making a later allocation attempt succeed immediately, but not attributing the success to compaction. Since stress-highalloc always tries to allocate almost the whole memory, it cannot show the improvement in its reported success rate metric. However after this patch, compaction should detect success and terminate earlier, reducing the direct compaction latencies in a real scenario. Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Christoph Lameter <cl@linux.com> Acked-by:
Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Vlastimil Babka authored
Compaction caches the migration and free scanner positions between compaction invocations, so that the whole zone gets eventually scanned and there is no bias towards the initial scanner positions at the beginning/end of the zone. The cached positions are continuously updated as scanners progress and the updating stops as soon as a page is successfully isolated. The reasoning behind this is that a pageblock where isolation succeeded is likely to succeed again in near future and it should be worth revisiting it. However, the downside is that potentially many pages are rescanned without successful isolation. At worst, there might be a page where isolation from LRU succeeds but migration fails (potentially always). So upon encountering this page, cached position would always stop being updated for no good reason. It might have been useful to let such page be rescanned with sync compaction after async one failed, but this is now handled by caching scanner position for async and sync mode separately since commit 35979ef3 ("mm, compaction: add per-zone migration pfn cache for async compaction"). After this patch, cached positions are updated unconditionally. In stress-highalloc benchmark, this has decreased the numbers of scanned pages by few percent, without affecting allocation success rates. To prevent free scanner from leaving free pages behind after they are returned due to page migration failure, the cached scanner pfn is changed to point to the pageblock of the returned free page with the highest pfn, before leaving compact_zone(). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
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Vlastimil Babka authored
Deferred compaction is employed to avoid compacting zone where sync direct compaction has recently failed. As such, it makes sense to only defer when a full zone was scanned, which is when compact_zone returns with COMPACT_COMPLETE. It's less useful to defer when compact_zone returns with apparent success (COMPACT_PARTIAL), followed by a watermark check failure, which can happen due to parallel allocation activity. It also does not make much sense to defer compaction which was completely skipped (COMPACT_SKIP) for being unsuitable in the first place. This patch therefore makes deferred compaction trigger only when COMPACT_COMPLETE is returned from compact_zone(). Results of stress-highalloc becnmark show the difference is within measurement error, so the issue is rather cosmetic. Signed-off-by:
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Vlastimil Babka authored
Since commit 53853e2d ("mm, compaction: defer each zone individually instead of preferred zone"), compaction is deferred for each zone where sync direct compaction fails, and reset where it succeeds. However, it was observed that for DMA zone compaction often appeared to succeed while subsequent allocation attempt would not, due to different outcome of watermark check. In order to properly defer compaction in this zone, the candidate zone has to be passed back to __alloc_pages_direct_compact() and compaction deferred in the zone after the allocation attempt fails. The large source of mismatch between watermark check in compaction and allocation was the lack of alloc_flags and classzone_idx values in compaction, which has been fixed in the previous patch. So with this problem fixed, we can simplify the code by removing the candidate_zone parameter and deferring in __alloc_pages_direct_compact(). After this patch, the compaction activity during stress-highalloc benchmark is still somewhat increased, but it's negligible compared to the increase that occurred without the better watermark checking. This suggests that it is still possible to apparently succeed in compaction but fail to allocate, possibly due to parallel allocation activity. [akpm@linux-foundation.org: fix build] Suggested-by:
Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
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Vlastimil Babka authored
Compaction relies on zone watermark checks for decisions such as if it's worth to start compacting in compaction_suitable() or whether compaction should stop in compact_finished(). The watermark checks take classzone_idx and alloc_flags parameters, which are related to the memory allocation request. But from the context of compaction they are currently passed as 0, including the direct compaction which is invoked to satisfy the allocation request, and could therefore know the proper values. The lack of proper values can lead to mismatch between decisions taken during compaction and decisions related to the allocation request. Lack of proper classzone_idx value means that lowmem_reserve is not taken into account. This has manifested (during recent changes to deferred compaction) when DMA zone was used as fallback for preferred Normal zone. compaction_suitable() without proper classzone_idx would think that the watermarks are already satisfied, but watermark check in get_page_from_freelist() would fail. Because of this problem, deferring compaction has extra complexity that can be removed in the following patch. The issue (not confirmed in practice) with missing alloc_flags is opposite in nature. For allocations that include ALLOC_HIGH, ALLOC_HIGHER or ALLOC_CMA in alloc_flags (the last includes all MOVABLE allocations on CMA-enabled systems) the watermark checking in compaction with 0 passed will be stricter than in get_page_from_freelist(). In these cases compaction might be running for a longer time than is really needed. Another issue compaction_suitable() is that the check for "does the zone need compaction at all?" comes only after the check "does the zone have enough free free pages to succeed compaction". The latter considers extra pages for migration and can therefore in some situations fail and return COMPACT_SKIPPED, although the high-order allocation would succeed and we should return COMPACT_PARTIAL. This patch fixes these problems by adding alloc_flags and classzone_idx to struct compact_control and related functions involved in direct compaction and watermark checking. Where possible, all other callers of compaction_suitable() pass proper values where those are known. This is currently limited to classzone_idx, which is sometimes known in kswapd context. However, the direct reclaim callers should_continue_reclaim() and compaction_ready() do not currently know the proper values, so the coordination between reclaim and compaction may still not be as accurate as it could. This can be fixed later, if it's shown to be an issue. Additionaly the checks in compact_suitable() are reordered to address the second issue described above. The effect of this patch should be slightly better high-order allocation success rates and/or less compaction overhead, depending on the type of allocations and presence of CMA. It allows simplifying deferred compaction code in a followup patch. When testing with stress-highalloc, there was some slight improvement (which might be just due to variance) in success rates of non-THP-like allocations. Signed-off-by:
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Jamie Liu authored
shrink_page_list() counts all pages with a mapping, including clean pages, toward nr_congested if they're on a write-congested BDI. shrink_inactive_list() then sets ZONE_CONGESTED if nr_dirty == nr_congested. Fix this apples-to-oranges comparison by only counting pages for nr_congested if they count for nr_dirty. Signed-off-by:
Jamie Liu <jamieliu@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by:
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Yu Zhao authored
This allows us to catch the bug fixed in the previous patch (mm: free compound page with correct order). Here we also verify whether a page is tail page or not -- tail pages are supposed to be freed along with their head, not by themselves. Signed-off-by:
Yu Zhao <yuzhao@google.com> Reviewed-by:
"Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: David Rientjes <rientjes@google.com> Cc: Bob Liu <lliubbo@gmail.com> Signed-off-by:
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Akinobu Mita authored
This makes CMA memory area size zero for x86 in default configuration (doesn't change on the other architectures). If default CMA size is zero, DMA_CMA is disabled. It can be enabled by passing cma= to the kernel. This makes less impact on x86. Because there is no mainline driver that requires it for x86, and Peter Hurley reported the performance regression, as this is trying to drive _all_ dma mapping allocations through a _very_ small window. Signed-off-by:
Akinobu Mita <akinobu.mita@gmail.com> Reported-by:
Peter Hurley <peter@hurleysoftware.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Chuck Ebbert <cebbert.lkml@gmail.com> Cc: Jean Delvare <jdelvare@suse.de> Acked-by:
Marek Szyprowski <m.szyprowski@samsung.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by:
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Vlastimil Babka authored
Memory hotplug and failure mechanisms have several places where pcplists are drained so that pages are returned to the buddy allocator and can be e.g. prepared for offlining. This is always done in the context of a single zone, we can reduce the pcplists drain to the single zone, which is now possible. The change should make memory offlining due to hotremove or failure faster and not disturbing unrelated pcplists anymore. Signed-off-by:
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Vlastimil Babka authored
CMA allocation drains pcplists so that pages can merge back to buddy allocator. Since it operates on a single zone, we can reduce the pcplists drain to the single zone, which is now possible. The change should make CMA allocations faster and not disturbing unrelated pcplists anymore. Signed-off-by:
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Vlastimil Babka authored
When setting MIGRATETYPE_ISOLATE on a pageblock, pcplists are drained to have a better chance that all pages will be successfully isolated and not left in the per-cpu caches. Since isolation is always concerned with a single zone, we can reduce the pcplists drain to the single zone, which is now possible. The change should make memory isolation faster and not disturbing unrelated pcplists anymore. Signed-off-by:
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Vlastimil Babka authored
The functions for draining per-cpu pages back to buddy allocators currently always operate on all zones. There are however several cases where the drain is only needed in the context of a single zone, and spilling other pcplists is a waste of time both due to the extra spilling and later refilling. This patch introduces new zone pointer parameter to drain_all_pages() and changes the dummy parameter of drain_local_pages() to be also a zone pointer. When NULL is passed, the functions operate on all zones as usual. Passing a specific zone pointer reduces the work to the single zone. All callers are updated to pass the NULL pointer in this patch. Conversion to single zone (where appropriate) is done in further patches. Signed-off-by:
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Pintu Kumar authored
This patch replaces printk(KERN_ERR..) with pr_err found under shrink_slab. Thus it also reduces one line extra because of formatting. Signed-off-by:
Pintu Kumar <pintu.k@samsung.com> Signed-off-by:
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Pintu Kumar authored
This patch replaces printk(KERN_WARNING..) with pr_warn. Thus it also reduces one line extra because of formatting. Signed-off-by:
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Anton Blanchard authored
Signed-off-by:
Anton Blanchard <anton@samba.org> Signed-off-by:
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Johannes Weiner authored
With charge reparenting, the last synchronous stock drainer left. Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Reviewed-by:
Vladimir Davydov <vdavydov@parallels.com> Acked-by:
Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
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Johannes Weiner authored
On cgroup deletion, outstanding page cache charges are moved to the parent group so that they're not lost and can be reclaimed during pressure on/inside said parent. But this reparenting is fairly tricky and its synchroneous nature has led to several lock-ups in the past. Since c2931b70 ("cgroup: iterate cgroup_subsys_states directly") css iterators now also include offlined css, so memcg iterators can be changed to include offlined children during reclaim of a group, and leftover cache can just stay put. There is a slight change of behavior in that charges of deleted groups no longer show up as local charges in the parent. But they are still included in the parent's hierarchical statistics. Signed-off-by:
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Johannes Weiner authored
As charges now pin the css explicitely, there is no more need for kmemcg to acquire a proxy reference for outstanding pages during offlining, or maintain state to identify such "dead" groups. This was the last user of the uncharge functions' return values, so remove them as well. Signed-off-by:
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Johannes Weiner authored
Charges currently pin the css indirectly by playing tricks during css_offline(): user pages stall the offlining process until all of them have been reparented, whereas kmemcg acquires a keep-alive reference if outstanding kernel pages are detected at that point. In preparation for removing all this complexity, make the pinning explicit and acquire a css references for every charged page. Signed-off-by:
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Johannes Weiner authored
The memcg reclaim iterators use a complicated weak reference scheme to prevent pinning cgroups indefinitely in the absence of memory pressure. However, during the ongoing cgroup core rework, css lifetime has been decoupled such that a pinned css no longer interferes with removal of the user-visible cgroup, and all this complexity is now unnecessary. [mhocko@suse.cz: ensure that the cached reference is always released] Signed-off-by:
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Johannes Weiner authored
All memory accounting and limiting has been switched over to the lockless page counters. Bye, res_counter! [akpm@linux-foundation.org: update Documentation/cgroups/memory.txt] [mhocko@suse.cz: ditch the last remainings of res_counter] Signed-off-by:
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Johannes Weiner authored
Abandon the spinlock-protected byte counters in favor of the unlocked page counters in the hugetlb controller as well. Signed-off-by:
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Johannes Weiner authored
Memory is internally accounted in bytes, using spinlock-protected 64-bit counters, even though the smallest accounting delta is a page. The counter interface is also convoluted and does too many things. Introduce a new lockless word-sized page counter API, then change all memory accounting over to it. The translation from and to bytes then only happens when interfacing with userspace. The removed locking overhead is noticable when scaling beyond the per-cpu charge caches - on a 4-socket machine with 144-threads, the following test shows the performance differences of 288 memcgs concurrently running a page fault benchmark: vanilla: 18631648.500498 task-clock (msec) # 140.643 CPUs utilized ( +- 0.33% ) 1,380,638 context-switches # 0.074 K/sec ( +- 0.75% ) 24,390 cpu-migrations # 0.001 K/sec ( +- 8.44% ) 1,843,305,768 page-faults # 0.099 M/sec ( +- 0.00% ) 50,134,994,088,218 cycles # 2.691 GHz ( +- 0.33% ) <not supported> stalled-cycles-frontend <not supported> stalled-cycles-backend 8,049,712,224,651 instructions # 0.16 insns per cycle ( +- 0.04% ) 1,586,970,584,979 branches # 85.176 M/sec ( +- 0.05% ) 1,724,989,949 branch-misses # 0.11% of all branches ( +- 0.48% ) 132.474343877 seconds time elapsed ( +- 0.21% ) lockless: 12195979.037525 task-clock (msec) # 133.480 CPUs utilized ( +- 0.18% ) 832,850 context-switches # 0.068 K/sec ( +- 0.54% ) 15,624 cpu-migrations # 0.001 K/sec ( +- 10.17% ) 1,843,304,774 page-faults # 0.151 M/sec ( +- 0.00% ) 32,811,216,801,141 cycles # 2.690 GHz ( +- 0.18% ) <not supported> stalled-cycles-frontend <not supported> stalled-cycles-backend 9,999,265,091,727 instructions # 0.30 insns per cycle ( +- 0.10% ) 2,076,759,325,203 branches # 170.282 M/sec ( +- 0.12% ) 1,656,917,214 branch-misses # 0.08% of all branches ( +- 0.55% ) 91.369330729 seconds time elapsed ( +- 0.45% ) On top of improved scalability, this also gets rid of the icky long long types in the very heart of memcg, which is great for 32 bit and also makes the code a lot more readable. Notable differences between the old and new API: - res_counter_charge() and res_counter_charge_nofail() become page_counter_try_charge() and page_counter_charge() resp. to match the more common kernel naming scheme of try_do()/do() - res_counter_uncharge_until() is only ever used to cancel a local counter and never to uncharge bigger segments of a hierarchy, so it's replaced by the simpler page_counter_cancel() - res_counter_set_limit() is replaced by page_counter_limit(), which expects its callers to serialize against themselves - res_counter_memparse_write_strategy() is replaced by page_counter_limit(), which rounds down to the nearest page size - rather than up. This is more reasonable for explicitely requested hard upper limits. - to keep charging light-weight, page_counter_try_charge() charges speculatively, only to roll back if the result exceeds the limit. Because of this, a failing bigger charge can temporarily lock out smaller charges that would otherwise succeed. The error is bounded to the difference between the smallest and the biggest possible charge size, so for memcg, this means that a failing THP charge can send base page charges into reclaim upto 2MB (4MB) before the limit would have been reached. This should be acceptable. [akpm@linux-foundation.org: add includes for WARN_ON_ONCE and memparse] [akpm@linux-foundation.org: add includes for WARN_ON_ONCE, memparse, strncmp, and PAGE_SIZE] Signed-off-by: -
Pranith Kumar authored
Recently lockless_dereference() was added which can be used in place of hard-coding smp_read_barrier_depends(). The following PATCH makes the change. Signed-off-by:
Pranith Kumar <bobby.prani@gmail.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.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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Andrew Morton authored
The code goes BUG, but doesn't tell us which bits were unexpectedly set. Print that out. 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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Andrey Ryabinin authored
Adding __printf(3, 4) to slab_err exposed following: mm/slub.c: In function `check_slab': mm/slub.c:852:4: warning: format `%u' expects argument of type `unsigned int', but argument 4 has type `const char *' [-Wformat=] s->name, page->objects, maxobj); ^ mm/slub.c:852:4: warning: too many arguments for format [-Wformat-extra-args] mm/slub.c:857:4: warning: format `%u' expects argument of type `unsigned int', but argument 4 has type `const char *' [-Wformat=] s->name, page->inuse, page->objects); ^ mm/slub.c:857:4: warning: too many arguments for format [-Wformat-extra-args] mm/slub.c: In function `on_freelist': mm/slub.c:905:4: warning: format `%d' expects argument of type `int', but argument 5 has type `long unsigned int' [-Wformat=] "should be %d", page->objects, max_objects); Fix first two warnings by removing redundant s->name. Fix the last by changing type of max_object from unsigned long to int. Signed-off-by:Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Acked-by:
David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
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Joonsoo Kim authored
Unlike SLUB, sometimes, object isn't started at the beginning of the slab in the SLAB. This causes the unalignment problem when after slab merging is supported by commit 12220dea ("mm/slab: support slab merge"). Alignment mismatch check is introduced ("mm/slab: fix unalignment problem on Malta with EVA due to slab merge") to prevent merge in this case. This causes undesirable result that merging happens between infrequently used kmem_caches if there are kmem_caches with same size and is 256 bytes, are merged into pool_workqueue rather than kmalloc-256, because kmem_caches for kmalloc are at the tail of the list. To prevent this situation, this patch reverses iteration order in find_mergeable() to find frequently used kmem_caches. This change helps to merge kmem_cache to frequently used kmem_caches, such as kmalloc kmem_caches. Signed-off-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> Signed-off-by:
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Vladimir Davydov authored
Currently we print the slabinfo header in the seq start method, which makes it unusable for showing leaks, so we have leaks_show, which does practically the same as s_show except it doesn't show the header. However, we can print the header in the seq show method - we only need to check if the current element is the first on the list. This will allow us to use the same set of seq iterators for both leaks and slabinfo reporting, which is nice. Signed-off-by:
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LQYMGT authored
Some code in mm/slab.c and mm/slub.c use whitespaces in indent. Clean them up. Signed-off-by:
LQYMGT <lqymgt@gmail.com> Acked-by:
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Jan Kara authored
At one place we assign major number we found to ret. That assignment is then never used and actually doesn't make any sense given how the code is currently structured (the assignment comes from pre-git times). Just remove it. Coverity id: 1226852. Signed-off-by:
Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Dan Carpenter authored
In commit 1faf2894 ("ocfs2_dlm: disallow a domain join if node maps mismatch") we introduced a new earlier NULL check so this one is not needed. Also static checkers complain because we dereference it first and then check for NULL. Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by:
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Dan Carpenter authored
"inode" isn't NULL here, and also we dereference it on the previous line so static checkers get annoyed. Signed-off-by:
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jiangyiwen authored
Do not set the filesystem readonly if the storage link is down. In this case, metadata is not corrupted and only -EIO is returned. And if it is indeed corrupted metadata, it has already called ocfs2_error() in ocfs2_validate_inode_block(). Signed-off-by:
Yiwen Jiang <jiangyiwen@huawei.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by:
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Xue jiufei authored
ocfs2_readpages() use nonblocking flag to avoid page lock inversion. It will trigger cluster hang because that flag OCFS2_LOCK_UPCONVERT_FINISHING is not cleared if nonblocking lock cannot be granted at once. The flag would prevent dc thread from downconverting. So other nodes cannot acheive this lockres for ever. So we should not set OCFS2_LOCK_UPCONVERT_FINISHING when receiving ast if nonblocking lock had already returned. Signed-off-by:
joyce.xue <xuejiufei@huawei.com> Reviewed-by:
Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by:
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Jan Kara authored
Error handling if creation of root of debugfs in ocfs2_init() fails is broken. Although error code is set we fail to exit ocfs2_init() with error and thus initialization ends with success. Later when mounting a filesystem, ocfs2 debugfs entries end up being created in the root of debugfs filesystem which is confusing. Fix the error handling to bail out. Coverity id: 1227009. 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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Goldwyn Rodrigues authored
Filesize is not a good indication that the file needs to be synced. An example where this breaks is: 1. Open the file in O_SYNC|O_RDWR 2. Read a small portion of the file (say 64 bytes) 3. Lseek to starting of the file 4. Write 64 bytes If the node crashes, it is not written out to disk because this was not committed in the journal and the other node which reads the file after recovery reads stale data (even if the write on the other node was successful) Signed-off-by:
Goldwyn Rodrigues <rgoldwyn@suse.de> Reviewed-by:
Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by:
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Junxiao Bi authored
Set nn_persistent_error to -ENOTCONN will stop reconnect since the "stop" condition in o2net_start_connect() will be true. stop = (nn->nn_sc || (nn->nn_persistent_error && (nn->nn_persistent_error != -ENOTCONN || timeout == 0))); This will make connection never be established if the first connection request is lost. Set nn_persistent_error to 0 when connect expired to fix this. With this changes, dlm will not be waken up when connect expired, this is OK since dlm depends on network, dlm can do nothing in this case if waken up. Let it wait there for network recover and connect built again to continue. Signed-off-by:Srinivas Eeda <srinivas.eeda@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by:
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Srinivas Eeda authored
Node A sends master query request to node B which is the master. At this time lockres happens to be on purgelist. dlm_master_request_handler gets the dlm spinlock, finds the resource and releases the dlm spin lock. Right at this dlm_thread on this node could purge the lockres. dlm_master_request_handler can then acquire lockres spinlock and reply to Node A that node B is the master even though lockres on node B is purged. The above scenario will now make node A falsely think node B is the master which is inconsistent. Further if another node C tries to master the same resource, every node will respond they are not the master. Node C then masters the resource and sends assert master to all nodes. This will now make node A crash with the following message. dlm_assert_master_handler:1831 ERROR: DIE! Mastery assert from 9, but current owner is 10! Signed-off-by:
Wengang Wang <wen.gang.wang@oracle.com> Tested-by:
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Jan Kara authored
Report return value of o2hb_do_disk_heartbeat() as a part of ML_HEARTBEAT message so that we know whether a heartbeat actually happened or not. This also makes assigned but otherwise unused 'ret' variable used. Coverity id: 1227053. Signed-off-by:
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Jan Kara authored
'args' are always set for ocfs2_read_locked_inode() and brelse() checks whether bh is NULL. So the test (args && bh) is unnecessary (plus the args part is really confusing anyway). Remove it. Coverity id: 1128856. Signed-off-by:
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