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xfs: use alloc_pages_bulk_array() for buffers

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Because it's more efficient than allocating pages one at a time in a
loop.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
This commit is contained in:
Dave Chinner 2021-06-01 13:40:36 +10:00 committed by Dave Chinner
parent 07b5c5add4
commit c9fa563072
1 changed files with 24 additions and 38 deletions
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62
fs/xfs/xfs_buf.c
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@ -386,10 +386,7 @@ xfs_buf_alloc_pages(
xfs_buf_flags_t flags)
{
gfp_t gfp_mask = xb_to_gfp(flags);
size_t size;
size_t offset;
size_t nbytes;
int i;
long filled = 0;
int error;
/* Assure zeroed buffer for non-read cases. */
@ -400,50 +397,39 @@ xfs_buf_alloc_pages(
if (unlikely(error))
return error;
offset = bp->b_offset;
bp->b_flags |= _XBF_PAGES;
for (i = 0; i < bp->b_page_count; i++) {
struct page *page;
uint retries = 0;
retry:
page = alloc_page(gfp_mask);
if (unlikely(page == NULL)) {
if (flags & XBF_READ_AHEAD) {
bp->b_page_count = i;
error = -ENOMEM;
goto out_free_pages;
}
/*
* Bulk filling of pages can take multiple calls. Not filling the entire
* array is not an allocation failure, so don't back off if we get at
* least one extra page.
*/
for (;;) {
long last = filled;
/*
* This could deadlock.
*
* But until all the XFS lowlevel code is revamped to
* handle buffer allocation failures we can't do much.
*/
if (!(++retries % 100))
xfs_err(NULL,
"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
current->comm, current->pid,
__func__, gfp_mask);
XFS_STATS_INC(bp->b_mount, xb_page_retries);
congestion_wait(BLK_RW_ASYNC, HZ/50);
goto retry;
filled = alloc_pages_bulk_array(gfp_mask, bp->b_page_count,
bp->b_pages);
if (filled == bp->b_page_count) {
XFS_STATS_INC(bp->b_mount, xb_page_found);
break;
}
XFS_STATS_INC(bp->b_mount, xb_page_found);
if (filled != last)
continue;
nbytes = min_t(size_t, size, PAGE_SIZE - offset);
size -= nbytes;
bp->b_pages[i] = page;
offset = 0;
if (flags & XBF_READ_AHEAD) {
error = -ENOMEM;
goto out_free_pages;
}
XFS_STATS_INC(bp->b_mount, xb_page_retries);
congestion_wait(BLK_RW_ASYNC, HZ / 50);
}
return 0;
out_free_pages:
for (i = 0; i < bp->b_page_count; i++)
__free_page(bp->b_pages[i]);
while (--filled >= 0)
__free_page(bp->b_pages[filled]);
bp->b_flags &= ~_XBF_PAGES;
return error;
}