linux/mm
Artem Bityutskiy 253c34e9b1 writeback: prevent unnecessary bdi threads wakeups
Finally, we can get rid of unnecessary wake-ups in bdi threads, which are very
bad for battery-driven devices.

There are two types of activities bdi threads do:
1. process bdi works from the 'bdi->work_list'
2. periodic write-back

So there are 2 sources of wake-up events for bdi threads:

1. 'bdi_queue_work()' - submits bdi works
2. '__mark_inode_dirty()' - adds dirty I/O to bdi's

The former already has bdi wake-up code. The latter does not, and this patch
adds it.

'__mark_inode_dirty()' is hot-path function, but this patch adds another
'spin_lock(&bdi->wb_lock)' there. However, it is taken only in rare cases when
the bdi has no dirty inodes. So adding this spinlock should be fine and should
not affect performance.

This patch makes sure bdi threads and the forker thread do not wake-up if there
is nothing to do. The forker thread will nevertheless wake up at least every
5 min. to check whether it has to kill a bdi thread. This can also be optimized,
but is not worth it.

This patch also tidies up the warning about unregistered bid, and turns it from
an ugly crocodile to a simple 'WARN()' statement.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:53:56 +02:00
..
backing-dev.c writeback: prevent unnecessary bdi threads wakeups 2010-08-07 18:53:56 +02:00
bootmem.c x86,nobootmem: make alloc_bootmem_node fall back to other node when 32bit numa is used 2010-07-20 16:25:40 -07:00
bounce.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
compaction.c mm: compaction: add a tunable that decides when memory should be compacted and when it should be reclaimed 2010-05-25 08:06:59 -07:00
debug-pagealloc.c generic debug pagealloc 2009-04-01 08:59:13 -07:00
dmapool.c dmapools: protect page_list walk in show_pools() 2009-06-30 18:56:00 -07:00
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 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.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse 2010-05-30 09:16:14 -07:00
fremap.c mm: clean up mm_counter 2010-03-06 11:26:23 -08:00
highmem.c highmem: remove unneeded #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT for debug_kmap_atomic() 2010-05-25 08:07:01 -07:00
hugetlb.c cpuset,mm: fix no node to alloc memory when changing cpuset's mems 2010-05-25 08:06:57 -07:00
hwpoison-inject.c HWPOISON: Don't do early filtering if filter is disabled 2009-12-16 12:20:01 +01:00
init-mm.c mm: consolidate init_mm definition 2009-06-16 19:47:28 -07:00
internal.h HWPOISON: add an interface to switch off/on all the page filters 2009-12-16 12:19:59 +01:00
Kconfig lmb: rename to memblock 2010-07-14 17:14:00 +10:00
Kconfig.debug trivial: improve help text for mm debug config options 2009-09-21 15:14:57 +02:00
kmemcheck.c kmemcheck: Fix build errors due to missing slab.h 2010-03-30 22:02:32 +09:00
kmemleak-test.c percpu: clean up percpu variable definitions 2009-06-24 15:13:48 +09:00
kmemleak.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
ksm.c mm: migration: share the anon_vma ref counts between KSM and page migration 2010-05-25 08:06:58 -07:00
maccess.c maccess,probe_kernel: Allow arch specific override probe_kernel_(read|write) 2010-01-07 11:58:36 -06:00
madvise.c HWPOISON: Add a madvise() injector for soft page offlining 2009-12-16 12:20:00 +01:00
Makefile lmb: rename to memblock 2010-07-14 17:14:00 +10:00
memblock.c lmb: rename to memblock 2010-07-14 17:14:00 +10:00
memcontrol.c memcg: fix wake up in oom wait queue 2010-06-29 15:29:30 -07:00
memory_hotplug.c mem-hotplug: fix potential race while building zonelist for new populated zone 2010-05-25 08:07:02 -07:00
memory-failure.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
memory.c mm: fix ia64 crash when gcore reads gate area 2010-07-30 18:56:09 -07:00
mempolicy.c mempolicy: fix dangling reference to tmpfs superblock mpol 2010-06-29 15:29:31 -07:00
mempool.c mm: remove broken 'kzalloc' mempool 2009-09-22 07:17:35 -07:00
migrate.c memcg: fix mis-accounting of file mapped racy with migration 2010-05-27 09:12:44 -07:00
mincore.c mincore: do nested page table walks 2010-05-25 08:06:58 -07:00
mlock.c x86, perf, bts, mm: Delete the never used BTS-ptrace code 2010-03-26 11:33:55 +01:00
mm_init.c mm: mminit_loglevel cannot be __meminitdata anymore 2008-08-20 15:40:30 -07:00
mmap.c mmap: check ->vm_ops before dereferencing 2010-04-27 08:26:51 -07:00
mmu_context.c exit: fix oops in sync_mm_rss 2010-03-24 16:31:21 -07:00
mmu_notifier.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
mmzone.c [ARM] Double check memmap is actually valid with a memmap has unexpected holes V2 2009-05-18 11:22:24 +01:00
mprotect.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
mremap.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
msync.c sanitize vfs_fsync calling conventions 2010-05-21 18:31:21 -04:00
nommu.c nommu: allow private mappings of read-only devices 2010-05-26 08:19:23 -07:00
oom_kill.c memcg: make oom killer a no-op when no killable task can be found 2010-05-27 09:12:43 -07:00
page_alloc.c x86,nobootmem: make alloc_bootmem_node fall back to other node when 32bit numa is used 2010-07-20 16:25:40 -07:00
page_cgroup.c kmemleak: Annotate false positive in init_section_page_cgroup() 2010-07-19 11:54:14 +01:00
page_io.c block: unify flags for struct bio and struct request 2010-08-07 18:20:39 +02:00
page_isolation.c memory hotplug: fix page_zone() calculation in test_pages_isolated() 2008-11-06 15:41:19 -08:00
page-writeback.c writeback: Add tracing to write_cache_pages 2010-08-07 18:24:26 +02:00
pagewalk.c pagemap: fix pfn calculation for hugepage 2010-04-07 08:38:04 -07:00
percpu_up.c percpu: don't implicitly include slab.h from percpu.h 2010-03-30 22:02:32 +09:00
percpu-km.c percpu: implement kernel memory based chunk allocation 2010-05-01 08:30:50 +02:00
percpu-vm.c percpu: move vmalloc based chunk management into percpu-vm.c 2010-05-01 08:30:50 +02:00
percpu.c percpu: fix first chunk match in per_cpu_ptr_to_phys() 2010-06-18 15:07:23 +02:00
prio_tree.c
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.c: fix comment 2010-05-25 08:07:00 -07:00
rmap.c mm: migration: avoid race between shift_arg_pages() and rmap_walk() during migration by not migrating temporary stacks 2010-05-25 08:06:59 -07:00
shmem.c fix truncate inode time modification breakage 2010-06-04 17:16:30 -04:00
slab.c numa: slab: use numa_mem_id() for slab local memory node 2010-05-27 09:12:57 -07:00
slob.c mm: Move ARCH_SLAB_MINALIGN and ARCH_KMALLOC_MINALIGN to <linux/slob_def.h> 2010-05-19 22:03:13 +03:00
slub.c Merge branch 'slub/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 2010-05-30 12:46:17 -07:00
sparse-vmemmap.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
sparse.c sparsemem: on no vmemmap path put mem_map on node high too 2010-05-25 08:06:56 -07:00
swap_state.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
swap.c mm: export lru_cache_add_*() to modules 2010-05-25 15:06:06 +02:00
swapfile.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6 2010-05-21 15:26:46 -07:00
thrash.c mm: pass mm to grab_swap_token 2009-06-23 12:50:05 -07:00
truncate.c fs: introduce new truncate sequence 2010-05-27 22:15:33 -04:00
util.c slab: Generify kernel pointer validation 2010-04-09 10:09:50 -07:00
vmalloc.c mm: purge fragmented percpu vmap blocks 2010-02-02 12:50:47 -08:00
vmscan.c mm/vmscan.c: fix mapping use after free 2010-07-20 16:25:40 -07:00
vmstat.c mm: compaction: direct compact when a high-order allocation fails 2010-05-25 08:06:59 -07:00