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51daa88ebd
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Wu Fengguang 51daa88ebd readahead: remove sync/async readahead call dependency 
The readahead call scheme is error-prone in that it expects the call sites
to check for async readahead after doing a sync one.  I.e.

			if (!page)
				page_cache_sync_readahead();
			page = find_get_page();
			if (page && PageReadahead(page))
				page_cache_async_readahead();

This is because PG_readahead could be set by a sync readahead for the
_current_ newly faulted in page, and the readahead code simply expects one
more callback on the same page to start the async readahead.  If the
caller fails to do so, it will miss the PG_readahead bits and never able
to start an async readahead.

Eliminate this insane constraint by piggy-backing the async part into the
current readahead window.

Now if an async readahead should be started immediately after a sync one,
the readahead logic itself will do it.  So the following code becomes
valid: (the 'else' in particular)

			if (!page)
				page_cache_sync_readahead();
			else if (PageReadahead(page))
				page_cache_async_readahead();

Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:29 -07:00
..
allocpercpu.c percpu: __percpu_depopulate_mask can take a const mask 2009-04-06 13:44:15 -07:00
backing-dev.c block: change the request allocation/congestion logic to be sync/async based 2009-04-06 08:04:53 -07:00
bootmem.c bootmem: fix slab fallback on numa 2009-06-11 19:15:54 +03:00
bounce.c Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block 2009-06-11 11:10:35 -07:00
debug-pagealloc.c generic debug pagealloc 2009-04-01 08:59:13 -07:00
dmapool.c dmapool: enable debugging for CONFIG_SLUB_DEBUG_ON too 2008-04-28 08:58:20 -07:00
fadvise.c readahead: move max_sane_readahead() calls into force_page_cache_readahead() 2009-06-16 19:47:28 -07:00
failslab.c kmemtrace, mm: fix slab.h dependency problem in mm/failslab.c 2009-04-03 12:23:01 +02:00
filemap_xip.c mm: do_xip_mapping_read: fix length calculation 2009-04-02 19:04:49 -07:00
filemap.c readahead: move max_sane_readahead() calls into force_page_cache_readahead() 2009-06-16 19:47:28 -07:00
fremap.c Do not account for the address space used by hugetlbfs using VM_ACCOUNT 2009-02-10 10:48:42 -08:00
highmem.c mm: introduce debug_kmap_atomic 2009-04-01 08:59:14 -07:00
hugetlb.c mm: account for MAP_SHARED mappings using VM_MAYSHARE and not VM_SHARED in hugetlbfs 2009-05-29 08:40:03 -07:00
init-mm.c mm: consolidate init_mm definition 2009-06-16 19:47:28 -07:00
internal.h nommu: there is no mlock() for NOMMU, so don't provide the bits 2009-04-01 08:59:14 -07:00
Kconfig security: use mmap_min_addr indepedently of security models 2009-06-04 12:07:48 +10:00
Kconfig.debug generic debug pagealloc: build fix 2009-04-02 19:04:48 -07:00
kmemleak-test.c kmemleak: Simple testing module for kmemleak 2009-06-11 17:04:19 +01:00
kmemleak.c kmemleak: Add the base support 2009-06-11 17:03:28 +01:00
maccess.c [S390] maccess: add weak attribute to probe_kernel_write 2009-06-12 10:27:37 +02:00
madvise.c readahead: move max_sane_readahead() calls into force_page_cache_readahead() 2009-06-16 19:47:28 -07:00
Makefile mm: consolidate init_mm definition 2009-06-16 19:47:28 -07:00
memcontrol.c memcg: fix build warning and avoid checking for mem != null again and again 2009-05-29 08:40:03 -07:00
memory_hotplug.c mm: remove GFP_HIGHUSER_PAGECACHE 2009-01-06 15:59:01 -08:00
memory.c mm: close page_mkwrite races 2009-05-02 15:36:09 -07:00
mempolicy.c [CVE-2009-0029] System call wrappers part 28 2009-01-14 14:15:30 +01:00
mempool.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
migrate.c FS-Cache: Recruit a page flags for cache management 2009-04-03 16:42:36 +01:00
mincore.c [CVE-2009-0029] System call wrappers part 14 2009-01-14 14:15:24 +01:00
mlock.c x86, bts, mm: clean up buffer allocation 2009-04-24 10:18:52 +02:00
mm_init.c mm: mminit_loglevel cannot be __meminitdata anymore 2008-08-20 15:40:30 -07:00
mmap.c Merge branch 'perfcounters-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-11 14:01:07 -07:00
mmu_notifier.c mmu-notifiers: core 2008-07-28 16:30:21 -07:00
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 perf_counter: Add mmap event hooks to mprotect() 2009-06-08 23:10:43 +02:00
mremap.c [CVE-2009-0029] System call wrappers part 13 2009-01-14 14:15:23 +01:00
msync.c [CVE-2009-0029] System call wrappers part 13 2009-01-14 14:15:23 +01:00
nommu.c nommu: Provide mmap_min_addr definition. 2009-06-10 09:24:09 +10:00
oom_kill.c oom: fix possible oom_dump_tasks NULL pointer 2009-05-29 08:40:01 -07:00
page_alloc.c kmemleak: Add kmemleak_alloc callback from alloc_large_system_hash 2009-06-11 17:03:30 +01:00
page_cgroup.c memcg: fix page_cgroup fatal error in FLATMEM 2009-06-12 11:00:54 +03:00
page_io.c block: fix bad definition of BIO_RW_SYNC 2009-02-18 10:32:00 +01:00
page_isolation.c memory hotplug: fix page_zone() calculation in test_pages_isolated() 2008-11-06 15:41:19 -08:00
page-writeback.c page-writeback: fix the calculation of the oldest_jif in wb_kupdate() 2009-05-17 16:36:11 -07:00
pagewalk.c pagemap: pass mm into pagewalkers 2008-06-12 18:05:41 -07:00
pdflush.c Revert "mm: add /proc controls for pdflush threads" 2009-05-15 11:32:24 +02:00
percpu.c percpu: remove rbtree and use page->index instead 2009-04-08 18:31:31 +02:00
prio_tree.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
quicklist.c cpumask: replace node_to_cpumask with cpumask_of_node. 2009-03-13 14:49:46 +10:30
readahead.c readahead: remove sync/async readahead call dependency 2009-06-16 19:47:29 -07:00
rmap.c hugh: update email address 2009-05-21 13:14:32 -07:00
shmem_acl.c [PATCH] sanitize ->permission() prototype 2008-07-26 20:53:14 -04:00
shmem.c integrity: move ima_counts_get 2009-05-22 09:45:33 +10:00
slab.c slab: setup cpu caches later on when interrupts are enabled 2009-06-12 18:53:58 +03:00
slob.c kmemleak: Add the slob memory allocation/freeing hooks 2009-06-11 17:03:30 +01:00
slub.c slab,slub: don't enable interrupts during early boot 2009-06-12 18:53:33 +03:00
sparse-vmemmap.c vmemmap: warn about page_structs with remote distance 2008-11-06 15:41:19 -08:00
sparse.c mm: mminit_validate_memmodel_limits(): remove redundant test 2009-04-01 08:59:11 -07:00
swap_state.c memcg: fix deadlock between lock_page_cgroup and mapping tree_lock 2009-05-29 08:40:02 -07:00
swap.c mm: fix Committed_AS underflow on large NR_CPUS environment 2009-05-02 15:36:10 -07:00
swapfile.c PM/hibernate: fix "swap breaks after hibernation failures" 2009-02-21 14:17:17 -08:00
thrash.c Bug in mm/thrash.c function grab_swap_token() 2007-05-11 08:29:32 -07:00
truncate.c memcg: fix deadlock between lock_page_cgroup and mapping tree_lock 2009-05-29 08:40:02 -07:00
util.c Merge branch 'linus' into tracing/core 2009-05-07 11:17:34 +02:00
vmalloc.c Merge branch 'for-linus' of git://linux-arm.org/linux-2.6 2009-06-11 14:15:57 -07:00
vmscan.c PM/Suspend: Do not shrink memory before suspend 2009-06-12 21:32:32 +02:00
vmstat.c [ARM] Double check memmap is actually valid with a memmap has unexpected holes V2 2009-05-18 11:22:24 +01:00