linux/mm
Christoph Hellwig f758eeabeb writeback: split inode_wb_list_lock into bdi_writeback.list_lock
Split the global inode_wb_list_lock into a per-bdi_writeback list_lock,
as it's currently the most contended lock in the system for metadata
heavy workloads.  It won't help for single-filesystem workloads for
which we'll need the I/O-less balance_dirty_pages, but at least we
can dedicate a cpu to spinning on each bdi now for larger systems.

Based on earlier patches from Nick Piggin and Dave Chinner.

It reduces lock contentions to 1/4 in this test case:
10 HDD JBOD, 100 dd on each disk, XFS, 6GB ram

lock_stat version 0.3
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                              class name    con-bounces    contentions   waittime-min   waittime-max waittime-total    acq-bounces   acquisitions   holdtime-min   holdtime-max holdtime-total
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
vanilla 2.6.39-rc3:
                      inode_wb_list_lock:         42590          44433           0.12         147.74      144127.35         252274         886792           0.08         121.34      917211.23
                      ------------------
                      inode_wb_list_lock              2          [<ffffffff81165da5>] bdev_inode_switch_bdi+0x29/0x85
                      inode_wb_list_lock             34          [<ffffffff8115bd0b>] inode_wb_list_del+0x22/0x49
                      inode_wb_list_lock          12893          [<ffffffff8115bb53>] __mark_inode_dirty+0x170/0x1d0
                      inode_wb_list_lock          10702          [<ffffffff8115afef>] writeback_single_inode+0x16d/0x20a
                      ------------------
                      inode_wb_list_lock              2          [<ffffffff81165da5>] bdev_inode_switch_bdi+0x29/0x85
                      inode_wb_list_lock             19          [<ffffffff8115bd0b>] inode_wb_list_del+0x22/0x49
                      inode_wb_list_lock           5550          [<ffffffff8115bb53>] __mark_inode_dirty+0x170/0x1d0
                      inode_wb_list_lock           8511          [<ffffffff8115b4ad>] writeback_sb_inodes+0x10f/0x157

2.6.39-rc3 + patch:
                &(&wb->list_lock)->rlock:         11383          11657           0.14         151.69       40429.51          90825         527918           0.11         145.90      556843.37
                ------------------------
                &(&wb->list_lock)->rlock             10          [<ffffffff8115b189>] inode_wb_list_del+0x5f/0x86
                &(&wb->list_lock)->rlock           1493          [<ffffffff8115b1ed>] writeback_inodes_wb+0x3d/0x150
                &(&wb->list_lock)->rlock           3652          [<ffffffff8115a8e9>] writeback_sb_inodes+0x123/0x16f
                &(&wb->list_lock)->rlock           1412          [<ffffffff8115a38e>] writeback_single_inode+0x17f/0x223
                ------------------------
                &(&wb->list_lock)->rlock              3          [<ffffffff8110b5af>] bdi_lock_two+0x46/0x4b
                &(&wb->list_lock)->rlock              6          [<ffffffff8115b189>] inode_wb_list_del+0x5f/0x86
                &(&wb->list_lock)->rlock           2061          [<ffffffff8115af97>] __mark_inode_dirty+0x173/0x1cf
                &(&wb->list_lock)->rlock           2629          [<ffffffff8115a8e9>] writeback_sb_inodes+0x123/0x16f

hughd@google.com: fix recursive lock when bdi_lock_two() is called with new the same as old
akpm@linux-foundation.org: cleanup bdev_inode_switch_bdi() comment

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-08 08:25:21 +08:00
..
backing-dev.c writeback: split inode_wb_list_lock into bdi_writeback.list_lock 2011-06-08 08:25:21 +08:00
bootmem.c crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn 2011-03-23 19:47:19 -07:00
bounce.c bounce: call flush_dcache_page() after bounce_copy_vec() 2010-09-09 18:57:25 -07:00
cleancache.c mm: cleancache core ops functions and config 2011-05-26 10:01:36 -06:00
compaction.c mm: compaction: minimise the time IRQs are disabled while isolating pages for migration 2011-03-22 17:44:05 -07:00
debug-pagealloc.c generic debug pagealloc 2009-04-01 08:59:13 -07:00
dmapool.c mm/dmapool.c: use TASK_UNINTERRUPTIBLE in dma_pool_alloc() 2011-01-13 17:32:48 -08:00
fadvise.c readahead: introduce FMODE_RANDOM for POSIX_FADV_RANDOM 2010-03-06 11:26:25 -08:00
failslab.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
filemap_xip.c mm: Convert i_mmap_lock to a mutex 2011-05-25 08:39:18 -07:00
filemap.c writeback: split inode_wb_list_lock into bdi_writeback.list_lock 2011-06-08 08:25:21 +08:00
fremap.c mm: don't access vm_flags as 'int' 2011-05-26 09:20:31 -07:00
highmem.c mm,x86: fix kmap_atomic_push vs ioremap_32.c 2010-10-27 18:03:05 -07:00
huge_memory.c mm: thp: optimize memcg charge in khugepaged 2011-05-25 08:39:21 -07:00
hugetlb.c mm: fix ENOSPC returned by handle_mm_fault() 2011-06-06 18:00:27 +09:00
hwpoison-inject.c Fix common misspellings 2011-03-31 11:26:23 -03:00
init-mm.c mm: convert mm->cpu_vm_cpumask into cpumask_var_t 2011-05-25 08:39:21 -07:00
internal.h mm: nommu: sort mm->mmap list properly 2011-05-25 08:39:05 -07:00
Kconfig mm: cleancache core ops functions and config 2011-05-26 10:01:36 -06:00
Kconfig.debug mm: debug-pagealloc: fix kconfig dependency warning 2011-03-22 17:44:02 -07:00
kmemcheck.c kmemcheck: Fix build errors due to missing slab.h 2010-03-30 22:02:32 +09:00
kmemleak-test.c kmemleak: remove memset by using kzalloc 2011-01-27 18:31:51 +00:00
kmemleak.c kmemleak: Do not return a pointer to an object that kmemleak did not get 2011-05-19 17:35:28 +01:00
ksm.c oom: replace PF_OOM_ORIGIN with toggling oom_score_adj 2011-05-25 08:39:10 -07:00
maccess.c maccess,probe_kernel: Make write/read src const void * 2011-05-25 19:56:23 -04:00
madvise.c thp: khugepaged: make khugepaged aware about madvise 2011-01-13 17:32:47 -08:00
Makefile mm: cleancache core ops functions and config 2011-05-26 10:01:36 -06:00
memblock.c mm/memblock: properly handle overlaps and fix error path 2011-03-22 17:44:09 -07:00
memcontrol.c memcg: add the pagefault count into memcg stats 2011-05-26 17:12:36 -07:00
memory_hotplug.c mm: remove dependency on CONFIG_FLATMEM from online_page() 2011-05-25 08:39:28 -07:00
memory-failure.c vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
memory.c memcg: add the pagefault count into memcg stats 2011-05-26 17:12:36 -07:00
mempolicy.c mm: proc: move show_numa_map() to fs/proc/task_mmu.c 2011-05-25 08:39:34 -07:00
mempool.c mm: remove broken 'kzalloc' mempool 2009-09-22 07:17:35 -07:00
migrate.c mm: use refcounts for page_lock_anon_vma() 2011-05-25 08:39:19 -07:00
mincore.c thp: mincore transparent hugepage support 2011-01-13 17:32:44 -08:00
mlock.c mm: don't access vm_flags as 'int' 2011-05-26 09:20:31 -07:00
mm_init.c
mmap.c mm: don't access vm_flags as 'int' 2011-05-26 09:20:31 -07:00
mmu_context.c exit: fix oops in sync_mm_rss 2010-03-24 16:31:21 -07:00
mmu_notifier.c thp: mmu_notifier_test_young 2011-01-13 17:32:46 -08:00
mmzone.c mm: page allocator: adjust the per-cpu counter threshold when memory is low 2011-01-13 17:32:31 -08:00
mprotect.c thp: mprotect: transparent huge page support 2011-01-13 17:32:44 -08:00
mremap.c mm: Convert i_mmap_lock to a mutex 2011-05-25 08:39:18 -07:00
msync.c sanitize vfs_fsync calling conventions 2010-05-21 18:31:21 -04:00
nobootmem.c memblock/nobootmem: remove unneeded code from alloc_bootmem_node_high() 2011-05-25 08:39:31 -07:00
nommu.c nommu: add page alignment to mmap 2011-05-25 08:39:38 -07:00
oom_kill.c oom: replace PF_OOM_ORIGIN with toggling oom_score_adj 2011-05-25 08:39:10 -07:00
page_alloc.c Revert "mm: fail GFP_DMA allocations when ZONE_DMA is not configured" 2011-06-02 06:11:24 +09:00
page_cgroup.c memcg: move page-freeing code out of lock 2011-05-26 17:12:35 -07:00
page_io.c block: kill off REQ_UNPLUG 2011-03-10 08:52:27 +01:00
page_isolation.c mm: page_isolation: codeclean fix comment and rm unneeded val init 2010-10-26 16:52:11 -07:00
page-writeback.c writeback: introduce .tagged_writepages for the WB_SYNC_NONE sync stage 2011-06-08 08:25:20 +08:00
pagewalk.c pagewalk: only split huge pages when necessary 2011-03-22 17:44:04 -07:00
percpu-km.c percpu: clear memory allocated with the km allocator 2010-10-02 10:28:42 +03:00
percpu-vm.c mm: remove gfp mask from pcpu_get_vm_areas 2011-01-13 17:32:34 -08:00
percpu.c Merge branch 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-05-24 11:53:42 -07:00
pgtable-generic.c mm/pgtable-generic.c: fix CONFIG_SWAP=n build 2011-01-26 10:49:58 +10:00
prio_tree.c sanitize <linux/prefetch.h> usage 2011-05-20 12:50:29 -07:00
quicklist.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
readahead.c readahead: readahead page allocations are OK to fail 2011-05-25 08:39:25 -07:00
rmap.c writeback: split inode_wb_list_lock into bdi_writeback.list_lock 2011-06-08 08:25:21 +08:00
shmem.c tmpfs: fix race between truncate and writepage 2011-05-28 16:09:26 -07:00
slab.c sanitize <linux/prefetch.h> usage 2011-05-20 12:50:29 -07:00
slob.c mm: Remove support for kmem_cache_name() 2011-01-23 21:00:05 +02:00
slub.c slub: remove no-longer used 'unlock_out' label 2011-05-25 18:06:54 -07:00
sparse-vmemmap.c tree-wide: fix comment/printk typos 2010-11-01 15:38:34 -04:00
sparse.c Fix common misspellings 2011-03-31 11:26:23 -03:00
swap_state.c block: remove per-queue plugging 2011-03-10 08:52:07 +01:00
swap.c mm: batch activate_page() to reduce lock contention 2011-05-25 08:39:37 -07:00
swapfile.c oom: replace PF_OOM_ORIGIN with toggling oom_score_adj 2011-05-25 08:39:10 -07:00
thrash.c mm: pass mm to grab_swap_token 2009-06-23 12:50:05 -07:00
truncate.c mm/fs: add hooks to support cleancache 2011-05-26 10:01:43 -06:00
util.c mm: nommu: sort mm->mmap list properly 2011-05-25 08:39:05 -07:00
vmalloc.c Merge branch 'upstream/tidy-xen-mmu-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2011-05-26 19:01:15 -07:00
vmscan.c memcg: rename mem_cgroup_zone_nr_pages() to mem_cgroup_zone_nr_lru_pages() 2011-05-26 17:12:35 -07:00
vmstat.c mm, mem-hotplug: update pcp->stat_threshold when memory hotplug occur 2011-05-25 08:39:09 -07:00