From: Dave Chinner <dchinner@xxxxxxxxxx>
Because it's more efficient than allocating pages one at a time in a
loop.
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
fs/xfs/xfs_buf.c | 62 +++++++++++++++++++-----------------------------
1 file changed, 24 insertions(+), 38 deletions(-)
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index b1610115d401..8ca4add138c5 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -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;
}
--
2.31.1
