From b8e24a9300b0836a9d39f6b20746766b3b81f1bd Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 8 Aug 2019 15:03:00 -0400 Subject: block: annotate refault stalls from IO submission psi tracks the time tasks wait for refaulting pages to become uptodate, but it does not track the time spent submitting the IO. The submission part can be significant if backing storage is contended or when cgroup throttling (io.latency) is in effect - a lot of time is spent in submit_bio(). In that case, we underreport memory pressure. Annotate submit_bio() to account submission time as memory stall when the bio is reading userspace workingset pages. Tested-by: Suren Baghdasaryan Signed-off-by: Johannes Weiner Signed-off-by: Jens Axboe --- block/bio.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'block/bio.c') diff --git a/block/bio.c b/block/bio.c index 24a496f5d2e2..54769659a434 100644 --- a/block/bio.c +++ b/block/bio.c @@ -806,6 +806,9 @@ void __bio_add_page(struct bio *bio, struct page *page, bio->bi_iter.bi_size += len; bio->bi_vcnt++; + + if (!bio_flagged(bio, BIO_WORKINGSET) && unlikely(PageWorkingset(page))) + bio_set_flag(bio, BIO_WORKINGSET); } EXPORT_SYMBOL_GPL(__bio_add_page); -- cgit v1.2.3