diff options
| author | Matthew Wilcox <willy@linux.intel.com> | 2008-05-19 16:34:27 +1000 |
|---|---|---|
| committer | Niv Sardi <xaiki@debian.org> | 2008-07-28 16:58:12 +1000 |
| commit | d748c62367eb630cc30b91d561a5362f597a0892 (patch) | |
| tree | 551fc30d6237517822edc6729456349e1bd0ab28 /fs | |
| parent | d729eae8933cb3eb8edf1446532c178b66b293a9 (diff) | |
| download | linux-d748c62367eb630cc30b91d561a5362f597a0892.tar.bz2 | |
[XFS] Convert l_flushsema to a sv_t
The l_flushsema doesn't exactly have completion semantics, nor mutex
semantics. It's used as a list of tasks which are waiting to be notified
that a flush has completed. It was also being used in a way that was
potentially racy, depending on the semaphore implementation.
By using a sv_t instead of a semaphore we avoid the need for a separate
counter, since we know we just need to wake everything on the queue.
Original waitqueue implementation from Matthew Wilcox. Cleanup and
conversion to sv_t by Christoph Hellwig.
SGI-PV: 981507
SGI-Modid: xfs-linux-melb:xfs-kern:31059a
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/xfs/xfs_log.c | 29 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_priv.h | 6 |
2 files changed, 15 insertions, 20 deletions
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 6195cc880101..91b00a5686cd 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1232,7 +1232,7 @@ xlog_alloc_log(xfs_mount_t *mp, spin_lock_init(&log->l_icloglock); spin_lock_init(&log->l_grant_lock); - initnsema(&log->l_flushsema, 0, "ic-flush"); + sv_init(&log->l_flush_wait, 0, "flush_wait"); /* log record size must be multiple of BBSIZE; see xlog_rec_header_t */ ASSERT((XFS_BUF_SIZE(bp) & BBMASK) == 0); @@ -1577,7 +1577,6 @@ xlog_dealloc_log(xlog_t *log) kmem_free(iclog); iclog = next_iclog; } - freesema(&log->l_flushsema); spinlock_destroy(&log->l_icloglock); spinlock_destroy(&log->l_grant_lock); @@ -2101,6 +2100,7 @@ xlog_state_do_callback( int funcdidcallbacks; /* flag: function did callbacks */ int repeats; /* for issuing console warnings if * looping too many times */ + int wake = 0; spin_lock(&log->l_icloglock); first_iclog = iclog = log->l_iclog; @@ -2282,15 +2282,13 @@ xlog_state_do_callback( } #endif - flushcnt = 0; - if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR)) { - flushcnt = log->l_flushcnt; - log->l_flushcnt = 0; - } + if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR)) + wake = 1; spin_unlock(&log->l_icloglock); - while (flushcnt--) - vsema(&log->l_flushsema); -} /* xlog_state_do_callback */ + + if (wake) + sv_broadcast(&log->l_flush_wait); +} /* @@ -2388,16 +2386,15 @@ restart: } iclog = log->l_iclog; - if (! (iclog->ic_state == XLOG_STATE_ACTIVE)) { - log->l_flushcnt++; - spin_unlock(&log->l_icloglock); + if (iclog->ic_state != XLOG_STATE_ACTIVE) { xlog_trace_iclog(iclog, XLOG_TRACE_SLEEP_FLUSH); XFS_STATS_INC(xs_log_noiclogs); - /* Ensure that log writes happen */ - psema(&log->l_flushsema, PINOD); + + /* Wait for log writes to have flushed */ + sv_wait(&log->l_flush_wait, 0, &log->l_icloglock, 0); goto restart; } - ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE); + head = &iclog->ic_header; atomic_inc(&iclog->ic_refcnt); /* prevents sync */ diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index 8952a392b5f3..6245913196b4 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -423,10 +423,8 @@ typedef struct log { int l_logBBsize; /* size of log in BB chunks */ /* The following block of fields are changed while holding icloglock */ - sema_t l_flushsema ____cacheline_aligned_in_smp; - /* iclog flushing semaphore */ - int l_flushcnt; /* # of procs waiting on this - * sema */ + sv_t l_flush_wait ____cacheline_aligned_in_smp; + /* waiting for iclog flush */ int l_covered_state;/* state of "covering disk * log entries" */ xlog_in_core_t *l_iclog; /* head log queue */ |