On Wed, Dec 16, 2015 at 12:13:16AM +0000, Adrian Chadd wrote:
> Author: adrian
> Date: Wed Dec 16 00:13:16 2015
> New Revision: 292299
> URL: https://svnweb.freebsd.org/changeset/base/292299
>
> Log:
> Don't call wakeup if we're just returning reserved space; just
> return the reservation and wait for more space to appear.
Issue which is supposedly fixed by the commit is not due to the possibly
excessive wakeups. bufspace_release() and bufspace_wakeup() clear
the needsbuffer variable, while the code flow in getnewbuf() calls
bufspace_wait() to wait for the condition, which prevented the buffer
allocation from succeeding, to pass.
>
> Submitted by: jeff
> Reviewed by: kib
>
> Modified:
> head/sys/kern/vfs_bio.c
>
> Modified: head/sys/kern/vfs_bio.c
> ==============================================================================
> --- head/sys/kern/vfs_bio.c Wed Dec 16 00:09:57 2015 (r292298)
> +++ head/sys/kern/vfs_bio.c Wed Dec 16 00:13:16 2015 (r292299)
> @@ -2909,7 +2909,7 @@ getnewbuf(struct vnode *vp, int slpflag,
> } while(buf_scan(false) == 0);
>
> if (reserved)
> - bufspace_release(maxsize);
> + atomic_subtract_long(&bufspace, maxsize);
> if (bp != NULL) {
> bp->b_flags |= B_INVAL;
> brelse(bp);
_______________________________________________
svn-src-head@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
