linux/mm
Artem Bityutskiy 080dcec417 writeback: simplify bdi code a little
This patch simplifies bdi code a little by removing the 'pending_list' which is
redundant. Indeed, currently the forker thread ('bdi_forker_thread()') is
working like this:

1. In a loop, fetch all bdi's which have works but have no writeback thread and
   move them to the 'pending_list'.
2. If the list is empty, sleep for 5 sec.
3. Otherwise, take one bdi from the list, fork the writeback thread for this
   bdi, and repeat the loop.

IOW, it first moves everything to the 'pending_list', then process only one
element, and so on. This patch simplifies the algorithm, which is now as
follows.

1. Find the first bdi which has a work and remove it from the global list of
   bdi's (bdi_list).
2. If there was not such bdi, sleep 5 sec.
3. Fork the writeback thread for this bdi and repeat the loop.

IOW, now we find the first bdi to process, process it, and so on. This is
simpler and involves less lists.

The bonus now is that we can get rid of a couple of functions, as well as
remove complications which involve 'rcu_call()' and 'bdi->rcu_head'.

This patch also makes sure we use 'list_add_tail_rcu()', instead of plain
'list_add_tail()', but this piece of code is going to be removed in the next
patch anyway.

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: simplify bdi code a little 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
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
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
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
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