Author: avg Date: Tue Feb 21 21:09:21 2017 New Revision: 314058 URL: https://svnweb.freebsd.org/changeset/base/314058
Log: zfs: lower priority of zio_write_issue threads by four The difference of one was insignificant because zio_write_issue threads ended up on the same run queues as other zio threads. See sys/priority.h and sys/runq.h for more details. Add a comment describing FreeBSD priority considerations and restore the illumos variant of the code for comparison. Obtained from: Panzura MFC after: 2 weeks Sponsored by: Panzura Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c Tue Feb 21 21:06:12 2017 (r314057) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c Tue Feb 21 21:09:21 2017 (r314058) @@ -922,9 +922,17 @@ spa_taskqs_init(spa_t *spa, zio_type_t t * The write issue taskq can be extremely CPU * intensive. Run it at slightly lower priority * than the other taskqs. + * FreeBSD notes: + * - numerically higher priorities are lower priorities; + * - if priorities divided by four (RQ_PPQ) are equal + * then a difference between them is insignificant. */ if (t == ZIO_TYPE_WRITE && q == ZIO_TASKQ_ISSUE) - pri++; +#ifdef illumos + pri--; +#else + pri += 4; +#endif tq = taskq_create_proc(name, value, pri, 50, INT_MAX, spa->spa_proc, flags); _______________________________________________ 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"