linux/mm
Christoph Hellwig bd5fe6c5eb fs: kill i_alloc_sem
i_alloc_sem is a rather special rw_semaphore.  It's the last one that may
be released by a non-owner, and it's write side is always mirrored by
real exclusion.  It's intended use it to wait for all pending direct I/O
requests to finish before starting a truncate.

Replace it with a hand-grown construct:

 - exclusion for truncates is already guaranteed by i_mutex, so it can
   simply fall way
 - the reader side is replaced by an i_dio_count member in struct inode
   that counts the number of pending direct I/O requests.  Truncate can't
   proceed as long as it's non-zero
 - when i_dio_count reaches non-zero we wake up a pending truncate using
   wake_up_bit on a new bit in i_flags
 - new references to i_dio_count can't appear while we are waiting for
   it to read zero because the direct I/O count always needs i_mutex
   (or an equivalent like XFS's i_iolock) for starting a new operation.

This scheme is much simpler, and saves the space of a spinlock_t and a
struct list_head in struct inode (typically 160 bits on a non-debug 64-bit
system).

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:46 -04:00
..
backing-dev.c backing-dev: Kill set but not used var in bdi_debug_stats_show() 2011-05-20 21:23:37 +02:00
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: abort compaction if too many pages are isolated and caller is asynchronous V2 2011-06-15 20:04:02 -07:00
debug-pagealloc.c
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 fs: kill i_alloc_sem 2011-07-20 20:47:46 -04:00
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: remove khugepaged double thp vmstat update with CONFIG_NUMA=n 2011-06-15 20:03:58 -07:00
hugetlb.c mm: fix negative commitlimit when gigantic hugepages are allocated 2011-06-15 20:04:01 -07:00
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 ksm: fix NULL pointer dereference in scan_get_next_rmap_item() 2011-06-15 20:04:02 -07:00
maccess.c maccess,probe_kernel: Make write/read src const void * 2011-05-25 19:56:23 -04:00
madvise.c fs: kill i_alloc_sem 2011-07-20 20:47:46 -04:00
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: fix numa scan information update to be triggered by memory event 2011-07-08 21:14:44 -07:00
memory_hotplug.c mm, hotplug: protect zonelist building with zonelists_mutex 2011-06-22 21:06:48 -07:00
memory-failure.c mm/memory-failure.c: fix spinlock vs mutex order 2011-06-27 18:00:13 -07:00
memory.c mm: __tlb_remove_page() check the correct batch 2011-07-08 21:14:43 -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 migrate: don't account swapcache as shmem 2011-06-16 15:01:24 -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: get rid of the most spurious find_vma_prev() users 2011-06-16 00:35:09 -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 mm/nommu.c: fix remap_pfn_range() 2011-07-08 21:14:44 -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: fix init_page_cgroup nid with sparsemem 2011-06-15 20:04:01 -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 Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
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 fs: kill i_alloc_sem 2011-07-20 20:47:46 -04:00
shmem.c tmpfs: add shmem_read_mapping_page_gfp 2011-06-27 18:00:12 -07:00
slab.c SLAB: Record actual last user of freed objects. 2011-06-03 19:33:50 +03:00
slob.c mm: Remove support for kmem_cache_name() 2011-01-23 21:00:05 +02:00
slub.c slub: always align cpu_slab to honor cmpxchg_double requirement 2011-06-03 19:33:49 +03:00
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 mm: move shmem prototypes to shmem_fs.h 2011-06-27 18:00:12 -07:00
thrash.c vmscan: implement swap token priority aging 2011-06-15 20:03:59 -07:00
truncate.c fs: kill i_alloc_sem 2011-07-20 20:47:46 -04:00
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 vmscan: add customisable shrinker batch size 2011-07-20 01:44:32 -04:00
vmstat.c mm, mem-hotplug: update pcp->stat_threshold when memory hotplug occur 2011-05-25 08:39:09 -07:00