From 5e943194067b1da56717bc57f75be17cc00ee87f Mon Sep 17 00:00:00 2001 From: Wang Shilong Date: Fri, 20 Jun 2014 19:09:07 +0800 Subject: Btrfs-progs: fsck: reduce memory usage for extents check Steps to reproduce: # mkfs.btrfs -f /dev/sda9 -b 2g # mount /dev/sda9 /mnt # dd if=/dev/zero of=/mnt/data bs=4k oflag=direct # btrfs file df /mnt Data, single: total=1.66GiB, used=1.66GiB System, single: total=4.00MiB, used=16.00KiB Metadata, single: total=200.00MiB, used=67.88MiB For a filesystem without snapshots, 70M metadata, extent checking eats max memory about 110M, this is a nightmare for some system with low memory. It is very likely that extent record can be freed quickly for a filesystem without snapshots, improve this by trying if it can free memory after adding data/tree backrefs. This patch reduces max memory cost from 110M to 40M for extents checking for the above case. Signed-off-by: Wang Shilong Signed-off-by: David Sterba --- cmds-check.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'cmds-check.c') diff --git a/cmds-check.c b/cmds-check.c index df4af9a1..b2e69672 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -2829,6 +2829,7 @@ static int add_tree_backref(struct cache_tree *extent_cache, u64 bytenr, } back->node.found_extent_tree = 1; } + maybe_free_extent_rec(extent_cache, rec); return 0; } @@ -2895,6 +2896,7 @@ static int add_data_backref(struct cache_tree *extent_cache, u64 bytenr, back->num_refs = num_refs; back->node.found_extent_tree = 1; } + maybe_free_extent_rec(extent_cache, rec); return 0; } -- cgit v1.2.3