Doug / smarc-fsl-linux-kernel

Download as
Browse Code ยป

Commit 39e2defe73106ca2e1c85e5286038a0a13f49513

Authored by Christoph Hellwig
Committed by Niv Sardi
1 parent d9424b3c4a
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

reduce l_icloglock roundtrips 

All but one caller of xlog_state_want_sync drop and re-acquire
l_icloglock around the call to it, just so that xlog_state_want_sync can
acquire and drop it.

Move all lock operation out of l_icloglock and assert that the lock is
held when it is called.

Note that it would make sense to extende this scheme to
xlog_state_release_iclog, but the locking in there is more complicated
and we'd like to keep the atomic_dec_and_lock optmization for those
callers not having l_icloglock yet.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>

Showing 1 changed file with 6 additions and 7 deletions Side-by-side Diff

... ... @@ -729,8 +729,8 @@
729 729 spin_lock(&log->l_icloglock);
730 730 iclog = log->l_iclog;
731 731 atomic_inc(&iclog->ic_refcnt);
732   - spin_unlock(&log->l_icloglock);
733 732 xlog_state_want_sync(log, iclog);
  733 + spin_unlock(&log->l_icloglock);
734 734 error = xlog_state_release_iclog(log, iclog);
735 735  
736 736 spin_lock(&log->l_icloglock);
737 737  
... ... @@ -767,9 +767,9 @@
767 767 spin_lock(&log->l_icloglock);
768 768 iclog = log->l_iclog;
769 769 atomic_inc(&iclog->ic_refcnt);
770   - spin_unlock(&log->l_icloglock);
771 770  
772 771 xlog_state_want_sync(log, iclog);
  772 + spin_unlock(&log->l_icloglock);
773 773 error = xlog_state_release_iclog(log, iclog);
774 774  
775 775 spin_lock(&log->l_icloglock);
776 776  
... ... @@ -1984,7 +1984,9 @@
1984 1984 if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
1985 1985 xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
1986 1986 record_cnt = data_cnt = 0;
  1987 + spin_lock(&log->l_icloglock);
1987 1988 xlog_state_want_sync(log, iclog);
  1989 + spin_unlock(&log->l_icloglock);
1988 1990 if (commit_iclog) {
1989 1991 ASSERT(flags & XLOG_COMMIT_TRANS);
1990 1992 *commit_iclog = iclog;
... ... @@ -3193,7 +3195,7 @@
3193 3195 STATIC void
3194 3196 xlog_state_want_sync(xlog_t *log, xlog_in_core_t *iclog)
3195 3197 {
3196   - spin_lock(&log->l_icloglock);
  3198 + ASSERT(spin_is_locked(&log->l_icloglock));
3197 3199  
3198 3200 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3199 3201 xlog_state_switch_iclogs(log, iclog, 0);
... ... @@ -3201,10 +3203,7 @@
3201 3203 ASSERT(iclog->ic_state &
3202 3204 (XLOG_STATE_WANT_SYNC|XLOG_STATE_IOERROR));
3203 3205 }
3204   -
3205   - spin_unlock(&log->l_icloglock);
3206   -} /* xlog_state_want_sync */
3207   -
  3206 +}
3208 3207  
3209 3208  
3210 3209 /*****************************************************************************