linux/mm
Christoph Lameter eebd2aa355 Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user
Simplify page cache zeroing of segments of pages through 3 functions

zero_user_segments(page, start1, end1, start2, end2)

        Zeros two segments of the page. It takes the position where to
        start and end the zeroing which avoids length calculations and
	makes code clearer.

zero_user_segment(page, start, end)

        Same for a single segment.

zero_user(page, start, length)

        Length variant for the case where we know the length.

We remove the zero_user_page macro. Issues:

1. Its a macro. Inline functions are preferable.

2. The KM_USER0 macro is only defined for HIGHMEM.

   Having to treat this special case everywhere makes the
   code needlessly complex. The parameter for zeroing is always
   KM_USER0 except in one single case that we open code.

Avoiding KM_USER0 makes a lot of code not having to be dealing
with the special casing for HIGHMEM anymore. Dealing with
kmap is only necessary for HIGHMEM configurations. In those
configurations we use KM_USER0 like we do for a series of other
functions defined in highmem.h.

Since KM_USER0 is depends on HIGHMEM the existing zero_user_page
function could not be a macro. zero_user_* functions introduced
here can be be inline because that constant is not used when these
functions are called.

Also extract the flushing of the caches to be outside of the kmap.

[akpm@linux-foundation.org: fix nfs and ntfs build]
[akpm@linux-foundation.org: fix ntfs build some more]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:13 -08:00
..
allocpercpu.c Slab allocators: Replace explicit zeroing with __GFP_ZERO 2007-07-17 10:23:02 -07:00
backing-dev.c mm/backing-dev.c: fix percpu_counter_destroy call bug in bdi_init 2007-12-05 09:21:18 -08:00
bootmem.c [PATCH] remove EXPORT_UNUSED_SYMBOL'ed symbols 2006-12-07 08:39:44 -08:00
bounce.c block: Initial support for data-less (or empty) barrier support 2007-10-16 11:03:56 +02:00
fadvise.c [PATCH] mm: change uses of f_{dentry,vfsmnt} to use f_path 2006-12-08 08:28:43 -08:00
filemap_xip.c Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
filemap.c fix writev regression: pan hanging unkillable and un-straceable 2008-02-03 07:55:39 +11:00
fremap.c sys_remap_file_pages: fix ->vm_file accounting 2008-02-05 09:44:07 -08:00
highmem.c Create the ZONE_MOVABLE zone 2007-07-17 10:22:59 -07:00
hugetlb.c fix hugepages leak due to pagetable page sharing 2008-01-24 08:07:27 -08:00
internal.h Breakout page_order() to internal.h to avoid special knowledge of the buddy allocator 2007-10-16 09:43:01 -07:00
Kconfig sh: Bump number of quicklists for SH-5. 2008-01-28 13:18:55 +09:00
madvise.c speed up madvise_need_mmap_write() usage 2007-07-16 09:05:36 -07:00
Makefile memory unplug: page isolation 2007-10-16 09:43:02 -07:00
memory_hotplug.c Add IORESOUCE_BUSY flag for System RAM 2007-11-14 18:45:39 -08:00
memory.c x86: print which shared library/executable faulted in segfault etc. messages v3 2008-01-30 13:33:18 +01:00
mempolicy.c Migration: find correct vma in new_vma_page() 2007-11-14 18:45:38 -08:00
mempool.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
migrate.c Typo fixes retrun -> return 2007-10-20 02:13:26 +02:00
mincore.c [PATCH] mincore: vma crossing fix 2007-02-15 09:57:03 -08:00
mlock.c do not limit locked memory when RLIMIT_MEMLOCK is RLIM_INFINITY 2007-07-16 09:05:37 -07:00
mmap.c vm audit: add VM_DONTEXPAND to mmap for drivers that need it 2008-02-04 07:55:38 -08:00
mmzone.c [PATCH] remove EXPORT_UNUSED_SYMBOL'ed symbols 2006-12-07 08:39:44 -08:00
mprotect.c fix mprotect vma_wants_writenotify prot 2007-10-23 08:32:06 -07:00
mremap.c sparse pointer use of zero as null 2007-10-18 14:37:31 -07:00
msync.c Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
nommu.c Security: round mmap hint address above mmap_min_addr 2007-12-06 00:25:10 +11:00
oom_kill.c sched: sched_rt_entity 2008-01-25 21:08:27 +01:00
page_alloc.c mm: fix section mismatch warning in page_alloc.c 2008-01-17 15:38:58 -08:00
page_io.c Drop 'size' argument from bio_endio and bi_end_io 2007-10-10 09:25:57 +02:00
page_isolation.c memory hotremove: unset migrate type "ISOLATE" after removal 2007-11-14 18:45:38 -08:00
page-writeback.c Revert "writeback: introduce writeback_control.more_io to indicate more io" 2008-01-14 21:21:29 -08:00
pdflush.c Freezer: make kernel threads nonfreezable by default 2007-07-17 10:23:02 -07:00
prio_tree.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
quicklist.c quicklists: Only consider memory that can be used with GFP_KERNEL 2008-01-14 08:52:22 -08:00
readahead.c mm: bdi init hooks 2007-10-17 08:42:45 -07:00
rmap.c [S390] Optimize storage key handling for anonymous pages 2007-11-20 11:13:46 +01:00
shmem_acl.c [PATCH] Fix typos in mm/shmem_acl.c 2006-10-11 11:14:23 -07:00
shmem.c tmpfs: restore missing clear_highpage 2007-11-28 11:04:28 -08:00
slab.c cpu-hotplug: replace per-subsystem mutexes with get_online_cpus() 2008-01-25 21:08:02 +01:00
slob.c Avoid double memclear() in SLOB/SLUB 2007-12-09 10:17:52 -08:00
slub.c SLUB: Do not upset lockdep 2008-02-04 10:56:02 -08:00
sparse-vmemmap.c memory hotplug fix: fix section mismatch in vmammap_allock_block() 2007-11-29 09:24:54 -08:00
sparse.c mm/sparse.c: improve the error handling for sparse_add_one_section() 2007-12-17 19:28:16 -08:00
swap_state.c mm: clarify __add_to_swap_cache locking 2007-10-16 09:42:53 -07:00
swap.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
swapfile.c Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION 2007-07-29 16:45:38 -07:00
thrash.c Bug in mm/thrash.c function grab_swap_token() 2007-05-11 08:29:32 -07:00
tiny-shmem.c r/o bind mounts: filesystem helpers for custom 'struct file's 2007-10-17 08:43:04 -07:00
truncate.c Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
util.c fix mm/util.c:krealloc() 2007-11-14 18:45:41 -08:00
vmalloc.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
vmscan.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
vmstat.c vmstat: fix section mismatch warning 2007-11-14 18:45:42 -08:00