Patchwork [3/3] ext4: Do no use yield() in ext4 code

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Submitter Lukas Czerner
Date March 8, 2013, 8:23 a.m.
Message ID <1362730998-3263-3-git-send-email-lczerner@redhat.com>
Download mbox | patch
Permalink /patch/226039/
State Accepted
Headers show

Comments

Lukas Czerner - March 8, 2013, 8:23 a.m.
Using yield() is strongly discouraged (see sched/core.c) especially
since we can just use cond_resched().

Replace all use of yield() with cond_resched().

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
---
 fs/ext4/inode.c   |    2 +-
 fs/ext4/mballoc.c |    8 ++------
 2 files changed, 3 insertions(+), 7 deletions(-)
Theodore Ts'o - March 11, 2013, 2:41 a.m.
On Fri, Mar 08, 2013 at 09:23:18AM +0100, Lukas Czerner wrote:
> Using yield() is strongly discouraged (see sched/core.c) especially
> since we can just use cond_resched().
> 
> Replace all use of yield() with cond_resched().
> 
> Signed-off-by: Lukas Czerner <lczerner@redhat.com>

Thanks, applied.

						- Ted
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Patch

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9ea0cde..ab28090 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1263,7 +1263,7 @@  repeat:
 		ei->i_da_metadata_calc_last_lblock = save_last_lblock;
 		spin_unlock(&ei->i_block_reservation_lock);
 		if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
-			yield();
+			cond_resched();
 			goto repeat;
 		}
 		dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 0a493a1..d2ec0d8 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3692,11 +3692,7 @@  repeat:
 	if (free < needed && busy) {
 		busy = 0;
 		ext4_unlock_group(sb, group);
-		/*
-		 * Yield the CPU here so that we don't get soft lockup
-		 * in non preempt case.
-		 */
-		yield();
+		cond_resched();
 		goto repeat;
 	}
 
@@ -4246,7 +4242,7 @@  ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
 			ext4_claim_free_clusters(sbi, ar->len, ar->flags)) {
 
 			/* let others to free the space */
-			yield();
+			cond_resched();
 			ar->len = ar->len >> 1;
 		}
 		if (!ar->len) {