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authorChristoph Hellwig <hch@lst.de>2022-09-15 12:41:58 +0300
committerJens Axboe <axboe@kernel.dk>2022-09-20 17:24:38 +0300
commit4088a47e78f95a5fea683cf67e0be006b13831fd (patch)
tree08246485b7e6b1e1847ad759f7986625dca24f78
parent527eb453bbfe65e5a55a90edfb1f30b477e36b8c (diff)
downloadlinux-4088a47e78f95a5fea683cf67e0be006b13831fd.tar.xz
btrfs: add manual PSI accounting for compressed reads
btrfs compressed reads try to always read the entire compressed chunk, even if only a subset is requested. Currently this is covered by the magic PSI accounting underneath submit_bio, but that is about to go away. Instead add manual psi_memstall_{enter,leave} annotations. Note that for readahead this really should be using readahead_expand, but the additionals reads are also done for plain ->read_folio where readahead_expand can't work, so this overall logic is left as-is for now. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David Sterba <dsterba@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20220915094200.139713-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--fs/btrfs/compression.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index e84d22c5c6a8..370788b9b124 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -15,6 +15,7 @@
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/writeback.h>
+#include <linux/psi.h>
#include <linux/slab.h>
#include <linux/sched/mm.h>
#include <linux/log2.h>
@@ -519,7 +520,8 @@ static u64 bio_end_offset(struct bio *bio)
*/
static noinline int add_ra_bio_pages(struct inode *inode,
u64 compressed_end,
- struct compressed_bio *cb)
+ struct compressed_bio *cb,
+ unsigned long *pflags)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
unsigned long end_index;
@@ -588,6 +590,9 @@ static noinline int add_ra_bio_pages(struct inode *inode,
continue;
}
+ if (PageWorkingset(page))
+ psi_memstall_enter(pflags);
+
ret = set_page_extent_mapped(page);
if (ret < 0) {
unlock_page(page);
@@ -674,6 +679,8 @@ void btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
u64 em_len;
u64 em_start;
struct extent_map *em;
+ /* Initialize to 1 to make skip psi_memstall_leave unless needed */
+ unsigned long pflags = 1;
blk_status_t ret;
int ret2;
int i;
@@ -729,7 +736,7 @@ void btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
goto fail;
}
- add_ra_bio_pages(inode, em_start + em_len, cb);
+ add_ra_bio_pages(inode, em_start + em_len, cb, &pflags);
/* include any pages we added in add_ra-bio_pages */
cb->len = bio->bi_iter.bi_size;
@@ -810,6 +817,9 @@ void btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
}
}
+ if (!pflags)
+ psi_memstall_leave(&pflags);
+
if (refcount_dec_and_test(&cb->pending_ios))
finish_compressed_bio_read(cb);
return;