From ec5857bf07639a03d32b8ecb346df634925f8bc2 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Mon, 16 Oct 2023 10:45:46 -0700 Subject: xfs: limit maxlen based on available space in xfs_rtallocate_extent_near() xfs_rtallocate_extent_near() calls xfs_rtallocate_extent_block() with the minlen and maxlen that were passed to it. xfs_rtallocate_extent_block() then scans the bitmap block looking for a free range of size maxlen. If there is none, it has to scan the whole bitmap block before returning the largest range of at least size minlen. For a fragmented realtime device and a large allocation request, it's almost certain that this will have to search the whole bitmap block, leading to high CPU usage. However, the realtime summary tells us the maximum size available in the bitmap block. We can limit the search in xfs_rtallocate_extent_block() to that size and often stop before scanning the whole bitmap block. Signed-off-by: Omar Sandoval Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_rtalloc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'fs/xfs/xfs_rtalloc.c') diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c index c774a4ccdd15..3aa9634a9e76 100644 --- a/fs/xfs/xfs_rtalloc.c +++ b/fs/xfs/xfs_rtalloc.c @@ -497,6 +497,9 @@ xfs_rtallocate_extent_near( * allocating one. */ if (maxlog >= 0) { + xfs_extlen_t maxavail = + min_t(xfs_rtblock_t, maxlen, + (1ULL << (maxlog + 1)) - 1); /* * On the positive side of the starting location. */ @@ -506,7 +509,7 @@ xfs_rtallocate_extent_near( * this block. */ error = xfs_rtallocate_extent_block(args, - bbno + i, minlen, maxlen, len, + bbno + i, minlen, maxavail, len, &n, prod, &r); if (error) { return error; @@ -553,7 +556,7 @@ xfs_rtallocate_extent_near( continue; error = xfs_rtallocate_extent_block(args, bbno + j, minlen, - maxlen, len, &n, prod, + maxavail, len, &n, prod, &r); if (error) { return error; @@ -575,7 +578,7 @@ xfs_rtallocate_extent_near( * that we found. */ error = xfs_rtallocate_extent_block(args, - bbno + i, minlen, maxlen, len, + bbno + i, minlen, maxavail, len, &n, prod, &r); if (error) { return error; -- cgit