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authorKotresh HR <khiremat@redhat.com>2016-05-09 16:54:00 +0530
committerJeff Darcy <jdarcy@redhat.com>2016-06-16 09:03:15 -0700
commit650459c4178eff6fba82351d044c995ab7d046b1 (patch)
treef8c1f3516fdb1c923ef8e8af29513f7287d7a860
parentdca4de364cd948ec7dade4416425ea1353911066 (diff)
features/changelog: Change barrier notification mechanism
Backport of http://review.gluster.org/14272 The barrier notification mechanism was fd based and 'select' was being used. 'select' breaks when number of fds opened by brick process exceeds 1024. To avoid this and also the maintainance of pipe between notify and 'changelog_rollover', the pipe has been replaced with pthread condition signal and timed wait mechanism. Change-Id: I530ea90d9a06953f8b23b4e12d122872ee1925de BUG: 1341952 Signed-off-by: Kotresh HR <khiremat@redhat.com> Reviewed-on: http://review.gluster.org/14615 Smoke: Gluster Build System <jenkins@build.gluster.org> NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org> CentOS-regression: Gluster Build System <jenkins@build.gluster.org> Reviewed-by: Raghavendra Bhat <raghavendra@redhat.com> Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
-rw-r--r--xlators/features/changelog/src/changelog-helpers.c81
-rw-r--r--xlators/features/changelog/src/changelog-helpers.h8
-rw-r--r--xlators/features/changelog/src/changelog.c53
3 files changed, 67 insertions, 75 deletions
diff --git a/xlators/features/changelog/src/changelog-helpers.c b/xlators/features/changelog/src/changelog-helpers.c
index ba98021..dd7fbbe 100644
--- a/xlators/features/changelog/src/changelog-helpers.c
+++ b/xlators/features/changelog/src/changelog-helpers.c
@@ -1210,15 +1210,10 @@ changelog_rollover (void *data)
{
int ret = 0;
xlator_t *this = NULL;
- struct timeval tv = {0,};
+ struct timespec tv = {0,};
changelog_log_data_t cld = {0,};
changelog_time_slice_t *slice = NULL;
changelog_priv_t *priv = data;
- int max_fd = 0;
- char buf[1] = {0};
- int len = 0;
-
- fd_set rset;
this = priv->cr.this;
slice = &priv->slice;
@@ -1226,44 +1221,41 @@ changelog_rollover (void *data)
while (1) {
(void) pthread_testcancel();
- tv.tv_sec = priv->rollover_time;
- tv.tv_usec = 0;
- FD_ZERO(&rset);
- FD_SET(priv->cr.rfd, &rset);
- max_fd = priv->cr.rfd;
- max_fd = max_fd + 1;
-
- /* It seems there is a race between actual rollover and explicit
- * rollover. But it is handled. If actual rollover is being
- * done and the explicit rollover event comes, the event is
- * not missed. The next select will immediately wakeup to
- * handle explicit wakeup.
+ tv.tv_sec = time (NULL) + priv->rollover_time;
+ tv.tv_nsec = 0;
+ ret = 0; /* Reset ret to zero */
+
+ /* The race between actual rollover and explicit rollover is
+ * handled. If actual rollover is being done and the
+ * explicit rollover event comes, the event is not missed.
+ * Since explicit rollover sets 'cr.notify' to true, this
+ * thread doesn't wait on 'pthread_cond_timedwait'.
*/
+ pthread_cleanup_push (changelog_cleanup_free_mutex,
+ &priv->cr.lock);
+ pthread_mutex_lock (&priv->cr.lock);
+ {
+ while (ret == 0 && !priv->cr.notify)
+ ret = pthread_cond_timedwait (&priv->cr.cond,
+ &priv->cr.lock,
+ &tv);
+ if (ret == 0)
+ priv->cr.notify = _gf_false;
+ }
+ pthread_mutex_unlock (&priv->cr.lock);
+ pthread_cleanup_pop (0);
- ret = select (max_fd, &rset, NULL, NULL, &tv);
- if (ret == -1) {
- gf_log (this->name, GF_LOG_ERROR,
- "select failed: %s", strerror(errno));
- continue;
- } else if (ret && FD_ISSET(priv->cr.rfd, &rset)) {
+ if (ret == 0) {
gf_log (this->name, GF_LOG_INFO,
- "Explicit wakeup of select on barrier notify");
- len = read(priv->cr.rfd, buf, 1);
- if (len == 0) {
- gf_log (this->name, GF_LOG_ERROR, "BUG: Got EOF"
- " from reconfigure notification pipe");
- continue;
- }
- if (len < 0) {
- gf_log (this->name, GF_LOG_ERROR,
- "Failed to read wakeup data");
- continue;
- }
- /* Lock is not required as same thread is modifying.*/
+ "Explicit wakeup on barrier notify");
priv->explicit_rollover = _gf_true;
- } else {
- gf_log (this->name, GF_LOG_DEBUG,
- "select wokeup on timeout");
+ } else if (ret && ret != ETIMEDOUT) {
+ gf_log (this->name, GF_LOG_ERROR,
+ "pthread_cond_timedwait failed: %s",
+ strerror (errno));
+ continue;
+ } else if (ret && ret == ETIMEDOUT) {
+ gf_log (this->name, GF_LOG_DEBUG, "Wokeup on timeout");
}
/* Reading curent_color without lock is fine here
@@ -1724,9 +1716,12 @@ changelog_barrier_notify (changelog_priv_t *priv, char *buf)
{
int ret = 0;
- LOCK(&priv->lock);
- ret = changelog_write (priv->cr_wfd, buf, 1);
- UNLOCK(&priv->lock);
+ pthread_mutex_lock (&priv->cr.lock);
+ {
+ ret = pthread_cond_signal (&priv->cr.cond);
+ priv->cr.notify = _gf_true;
+ }
+ pthread_mutex_unlock (&priv->cr.lock);
return ret;
}
diff --git a/xlators/features/changelog/src/changelog-helpers.h b/xlators/features/changelog/src/changelog-helpers.h
index 1d548ca..3f77ed5 100644
--- a/xlators/features/changelog/src/changelog-helpers.h
+++ b/xlators/features/changelog/src/changelog-helpers.h
@@ -115,8 +115,9 @@ typedef struct changelog_rollover {
xlator_t *this;
- /* read end of pipe used as event from barrier on snapshot */
- int rfd;
+ pthread_mutex_t lock;
+ pthread_cond_t cond;
+ gf_boolean_t notify;
} changelog_rollover_t;
typedef struct changelog_fsync {
@@ -264,9 +265,6 @@ struct changelog_priv {
/* Represents the active color. Initially by default black */
chlog_fop_color_t current_color;
- /* write end of pipe to do explicit rollover on barrier during snap */
- int cr_wfd;
-
/* flag to determine explicit rollover is triggered */
gf_boolean_t explicit_rollover;
diff --git a/xlators/features/changelog/src/changelog.c b/xlators/features/changelog/src/changelog.c
index 8898d51..6c38293 100644
--- a/xlators/features/changelog/src/changelog.c
+++ b/xlators/features/changelog/src/changelog.c
@@ -2028,11 +2028,6 @@ changelog_cleanup_helper_threads (xlator_t *this, changelog_priv_t *priv)
if (priv->cr.rollover_th) {
(void) changelog_thread_cleanup (this, priv->cr.rollover_th);
priv->cr.rollover_th = 0;
- ret = close (priv->cr_wfd);
- if (ret)
- gf_log (this->name, GF_LOG_ERROR,
- "error closing write end of rollover pipe"
- " (reason: %s)", strerror (errno));
}
if (priv->cf.fsync_th) {
@@ -2047,7 +2042,6 @@ changelog_spawn_helper_threads (xlator_t *this, changelog_priv_t *priv)
{
int ret = 0;
int flags = 0;
- int pipe_fd[2] = {0, 0};
/* Geo-Rep snapshot dependency:
*
@@ -2061,27 +2055,7 @@ changelog_spawn_helper_threads (xlator_t *this, changelog_priv_t *priv)
* the write end of the pipe in 'reconfigure'.
*/
- ret = pipe (pipe_fd);
- if (ret == -1) {
- gf_log (this->name, GF_LOG_ERROR,
- "Cannot create pipe (reason: %s)", strerror (errno));
- goto out;
- }
-
- /* writer is non-blocking */
- flags = fcntl (pipe_fd[1], F_GETFL);
- flags |= O_NONBLOCK;
-
- ret = fcntl (pipe_fd[1], F_SETFL, flags);
- if (ret) {
- gf_log (this->name, GF_LOG_ERROR,
- "failed to set O_NONBLOCK flag");
- goto out;
- }
-
- priv->cr_wfd = pipe_fd[1];
- priv->cr.rfd = pipe_fd[0];
-
+ priv->cr.notify = _gf_false;
priv->cr.this = this;
ret = gf_thread_create (&priv->cr.rollover_th,
NULL, changelog_rollover, priv);
@@ -2384,6 +2358,8 @@ changelog_barrier_pthread_init (xlator_t *this, changelog_priv_t *priv)
gf_boolean_t dm_cond_black_init = _gf_false;
gf_boolean_t dm_mutex_white_init = _gf_false;
gf_boolean_t dm_cond_white_init = _gf_false;
+ gf_boolean_t cr_mutex_init = _gf_false;
+ gf_boolean_t cr_cond_init = _gf_false;
int ret = 0;
if ((ret = pthread_mutex_init(&priv->bn.bnotify_mutex, NULL)) != 0) {
@@ -2435,6 +2411,22 @@ changelog_barrier_pthread_init (xlator_t *this, changelog_priv_t *priv)
goto out;
}
dm_cond_white_init = _gf_true;
+
+ if ((pthread_mutex_init(&priv->cr.lock, NULL)) != 0) {
+ gf_log (this->name, GF_LOG_ERROR,
+ "changelog_rollover lock init failed (%d)", ret);
+ ret = -1;
+ goto out;
+ }
+ cr_mutex_init = _gf_true;
+
+ if ((pthread_cond_init(&priv->cr.cond, NULL)) != 0) {
+ gf_log (this->name, GF_LOG_ERROR,
+ "changelog_rollover cond init failed (%d)", ret);
+ ret = -1;
+ goto out;
+ }
+ cr_cond_init = _gf_true;
out:
if (ret) {
if (bn_mutex_init)
@@ -2449,6 +2441,10 @@ changelog_barrier_pthread_init (xlator_t *this, changelog_priv_t *priv)
pthread_mutex_destroy(&priv->dm.drain_white_mutex);
if (dm_cond_white_init)
pthread_cond_destroy (&priv->dm.drain_white_cond);
+ if (cr_mutex_init)
+ pthread_mutex_destroy(&priv->cr.lock);
+ if (cr_cond_init)
+ pthread_cond_destroy (&priv->cr.cond);
}
return ret;
}
@@ -2463,6 +2459,8 @@ changelog_barrier_pthread_destroy (changelog_priv_t *priv)
pthread_cond_destroy (&priv->dm.drain_black_cond);
pthread_mutex_destroy (&priv->dm.drain_white_mutex);
pthread_cond_destroy (&priv->dm.drain_white_cond);
+ pthread_mutex_destroy(&priv->cr.lock);
+ pthread_cond_destroy (&priv->cr.cond);
LOCK_DESTROY (&priv->bflags.lock);
}
@@ -2786,6 +2784,7 @@ init (xlator_t *this)
priv->current_color = FOP_COLOR_BLACK;
priv->explicit_rollover = _gf_false;
+ priv->cr.notify = _gf_false;
/* Mutex is not needed as threads are not spawned yet */
priv->bn.bnotify = _gf_false;
priv->bn.bnotify_error = _gf_false;