Date: Sun, 5 Jan 2014 23:00:38 +0000 (UTC) From: Alexander Motin <mav@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r260354 - stable/10/sys/kern Message-ID: <201401052300.s05N0cPs020617@svn.freebsd.org>
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Author: mav Date: Sun Jan 5 23:00:38 2014 New Revision: 260354 URL: http://svnweb.freebsd.org/changeset/base/260354 Log: MFC r256614: - Take BIO lock in biodone() only when there is no completion callback set and so we should wake up thread waiting in biowait(). - Remove msleep() timeout from biowait(). It was added 11 years ago, when there was no locks used, and it should not be needed any more. Modified: stable/10/sys/kern/vfs_bio.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/kern/vfs_bio.c ============================================================================== --- stable/10/sys/kern/vfs_bio.c Sun Jan 5 22:55:21 2014 (r260353) +++ stable/10/sys/kern/vfs_bio.c Sun Jan 5 23:00:38 2014 (r260354) @@ -3559,9 +3559,6 @@ biodone(struct bio *bp) vm_offset_t start, end; int transient; - mtxp = mtx_pool_find(mtxpool_sleep, bp); - mtx_lock(mtxp); - bp->bio_flags |= BIO_DONE; if ((bp->bio_flags & BIO_TRANSIENT_MAPPING) != 0) { start = trunc_page((vm_offset_t)bp->bio_data); end = round_page((vm_offset_t)bp->bio_data + bp->bio_length); @@ -3571,11 +3568,16 @@ biodone(struct bio *bp) start = end = 0; } done = bp->bio_done; - if (done == NULL) + if (done == NULL) { + mtxp = mtx_pool_find(mtxpool_sleep, bp); + mtx_lock(mtxp); + bp->bio_flags |= BIO_DONE; wakeup(bp); - mtx_unlock(mtxp); - if (done != NULL) + mtx_unlock(mtxp); + } else { + bp->bio_flags |= BIO_DONE; done(bp); + } if (transient) { pmap_qremove(start, OFF_TO_IDX(end - start)); vmem_free(transient_arena, start, end - start); @@ -3585,9 +3587,6 @@ biodone(struct bio *bp) /* * Wait for a BIO to finish. - * - * XXX: resort to a timeout for now. The optimal locking (if any) for this - * case is not yet clear. */ int biowait(struct bio *bp, const char *wchan) @@ -3597,7 +3596,7 @@ biowait(struct bio *bp, const char *wcha mtxp = mtx_pool_find(mtxpool_sleep, bp); mtx_lock(mtxp); while ((bp->bio_flags & BIO_DONE) == 0) - msleep(bp, mtxp, PRIBIO, wchan, hz / 10); + msleep(bp, mtxp, PRIBIO, wchan, 0); mtx_unlock(mtxp); if (bp->bio_error != 0) return (bp->bio_error);
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