[PATCH 5/5] block: remove PSI accounting from the bio layer

[Christoph Hellwig]

PSI accounting is now done by the VM code, where it should have been
since the beginning.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Acked-by: Johannes Weiner <hannes at cmpxchg.org>
---
 block/bio.c               |  8 --------
 block/blk-core.c          | 17 -----------------
 fs/direct-io.c            |  2 --
 include/linux/blk_types.h |  1 -
 4 files changed, 28 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 3d3a2678fea25..d10c4e888cdcf 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1065,9 +1065,6 @@ 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);
 
@@ -1276,9 +1273,6 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
  * fit into the bio, or are requested in @iter, whatever is smaller. If
  * MM encounters an error pinning the requested pages, it stops. Error
  * is returned only if 0 pages could be pinned.
- *
- * It's intended for direct IO, so doesn't do PSI tracking, the caller is
- * responsible for setting BIO_WORKINGSET if necessary.
  */
 int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
 {
@@ -1294,8 +1288,6 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
 		ret = __bio_iov_iter_get_pages(bio, iter);
 	} while (!ret && iov_iter_count(iter) && !bio_full(bio, 0));
 
-	/* don't account direct I/O as memory stall */
-	bio_clear_flag(bio, BIO_WORKINGSET);
 	return bio->bi_vcnt ? 0 : ret;
 }
 EXPORT_SYMBOL_GPL(bio_iov_iter_get_pages);
diff --git a/block/blk-core.c b/block/blk-core.c
index a0d1104c5590c..9e19195af6f5b 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -37,7 +37,6 @@
 #include <linux/t10-pi.h>
 #include <linux/debugfs.h>
 #include <linux/bpf.h>
-#include <linux/psi.h>
 #include <linux/part_stat.h>
 #include <linux/sched/sysctl.h>
 #include <linux/blk-crypto.h>
@@ -829,22 +828,6 @@ void submit_bio(struct bio *bio)
 		count_vm_events(PGPGOUT, bio_sectors(bio));
 	}
 
-	/*
-	 * If we're reading data that is part of the userspace workingset, count
-	 * submission time as memory stall.  When the device is congested, or
-	 * the submitting cgroup IO-throttled, submission can be a significant
-	 * part of overall IO time.
-	 */
-	if (unlikely(bio_op(bio) == REQ_OP_READ &&
-	    bio_flagged(bio, BIO_WORKINGSET))) {
-		unsigned long pflags;
-
-		psi_memstall_enter(&pflags);
-		submit_bio_noacct(bio);
-		psi_memstall_leave(&pflags);
-		return;
-	}
-
 	submit_bio_noacct(bio);
 }
 EXPORT_SYMBOL(submit_bio);
diff --git a/fs/direct-io.c b/fs/direct-io.c
index f669163d5860f..03d381377ae10 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -421,8 +421,6 @@ static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
 	unsigned long flags;
 
 	bio->bi_private = dio;
-	/* don't account direct I/O as memory stall */
-	bio_clear_flag(bio, BIO_WORKINGSET);
 
 	spin_lock_irqsave(&dio->bio_lock, flags);
 	dio->refcount++;
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 1ef99790f6ed3..8b1858df21752 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -321,7 +321,6 @@ enum {
 	BIO_NO_PAGE_REF,	/* don't put release vec pages */
 	BIO_CLONED,		/* doesn't own data */
 	BIO_BOUNCED,		/* bio is a bounce bio */
-	BIO_WORKINGSET,		/* contains userspace workingset pages */
 	BIO_QUIET,		/* Make BIO Quiet */
 	BIO_CHAIN,		/* chained bio, ->bi_remaining in effect */
 	BIO_REFFED,		/* bio has elevated ->bi_cnt */
-- 
2.30.2