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authorDavid Teigland <teigland@redhat.com>2011-03-28 14:17:26 -0500
committerDavid Teigland <teigland@redhat.com>2011-04-01 14:19:06 -0500
commitc6ff669bac5c409f4cb74366248f51b73f7d6feb (patch)
tree14c4b7dc943a7dde8fd6d80bc9d149dadc0d59b8 /fs/dlm/lock.c
parent4bcad6c1ef53a9a0224f4654ceb3b9030d0769ec (diff)
downloadlinux-linaro-stable-c6ff669bac5c409f4cb74366248f51b73f7d6feb.tar.gz
dlm: delayed reply message warning
Add an option (disabled by default) to print a warning message when a lock has been waiting a configurable amount of time for a reply message from another node. This is mainly for debugging. Signed-off-by: David Teigland <teigland@redhat.com>
Diffstat (limited to 'fs/dlm/lock.c')
-rw-r--r--fs/dlm/lock.c100
1 files changed, 93 insertions, 7 deletions
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 04b8c449303f..e3c864120371 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -799,10 +799,84 @@ static int msg_reply_type(int mstype)
return -1;
}
+static int nodeid_warned(int nodeid, int num_nodes, int *warned)
+{
+ int i;
+
+ for (i = 0; i < num_nodes; i++) {
+ if (!warned[i]) {
+ warned[i] = nodeid;
+ return 0;
+ }
+ if (warned[i] == nodeid)
+ return 1;
+ }
+ return 0;
+}
+
+void dlm_scan_waiters(struct dlm_ls *ls)
+{
+ struct dlm_lkb *lkb;
+ ktime_t zero = ktime_set(0, 0);
+ s64 us;
+ s64 debug_maxus = 0;
+ u32 debug_scanned = 0;
+ u32 debug_expired = 0;
+ int num_nodes = 0;
+ int *warned = NULL;
+
+ if (!dlm_config.ci_waitwarn_us)
+ return;
+
+ mutex_lock(&ls->ls_waiters_mutex);
+
+ list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
+ if (ktime_equal(lkb->lkb_wait_time, zero))
+ continue;
+
+ debug_scanned++;
+
+ us = ktime_to_us(ktime_sub(ktime_get(), lkb->lkb_wait_time));
+
+ if (us < dlm_config.ci_waitwarn_us)
+ continue;
+
+ lkb->lkb_wait_time = zero;
+
+ debug_expired++;
+ if (us > debug_maxus)
+ debug_maxus = us;
+
+ if (!num_nodes) {
+ num_nodes = ls->ls_num_nodes;
+ warned = kmalloc(GFP_KERNEL, num_nodes * sizeof(int));
+ if (warned)
+ memset(warned, 0, num_nodes * sizeof(int));
+ }
+ if (!warned)
+ continue;
+ if (nodeid_warned(lkb->lkb_wait_nodeid, num_nodes, warned))
+ continue;
+
+ log_error(ls, "waitwarn %x %lld %d us check connection to "
+ "node %d", lkb->lkb_id, (long long)us,
+ dlm_config.ci_waitwarn_us, lkb->lkb_wait_nodeid);
+ }
+ mutex_unlock(&ls->ls_waiters_mutex);
+
+ if (warned)
+ kfree(warned);
+
+ if (debug_expired)
+ log_debug(ls, "scan_waiters %u warn %u over %d us max %lld us",
+ debug_scanned, debug_expired,
+ dlm_config.ci_waitwarn_us, (long long)debug_maxus);
+}
+
/* add/remove lkb from global waiters list of lkb's waiting for
a reply from a remote node */
-static int add_to_waiters(struct dlm_lkb *lkb, int mstype)
+static int add_to_waiters(struct dlm_lkb *lkb, int mstype, int to_nodeid)
{
struct dlm_ls *ls = lkb->lkb_resource->res_ls;
int error = 0;
@@ -842,6 +916,8 @@ static int add_to_waiters(struct dlm_lkb *lkb, int mstype)
lkb->lkb_wait_count++;
lkb->lkb_wait_type = mstype;
+ lkb->lkb_wait_time = ktime_get();
+ lkb->lkb_wait_nodeid = to_nodeid; /* for debugging */
hold_lkb(lkb);
list_add(&lkb->lkb_wait_reply, &ls->ls_waiters);
out:
@@ -1157,6 +1233,16 @@ void dlm_adjust_timeouts(struct dlm_ls *ls)
list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list)
lkb->lkb_timestamp = ktime_add_us(lkb->lkb_timestamp, adj_us);
mutex_unlock(&ls->ls_timeout_mutex);
+
+ if (!dlm_config.ci_waitwarn_us)
+ return;
+
+ mutex_lock(&ls->ls_waiters_mutex);
+ list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
+ if (ktime_to_us(lkb->lkb_wait_time))
+ lkb->lkb_wait_time = ktime_get();
+ }
+ mutex_unlock(&ls->ls_waiters_mutex);
}
/* lkb is master or local copy */
@@ -2844,12 +2930,12 @@ static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype)
struct dlm_mhandle *mh;
int to_nodeid, error;
- error = add_to_waiters(lkb, mstype);
+ to_nodeid = r->res_nodeid;
+
+ error = add_to_waiters(lkb, mstype, to_nodeid);
if (error)
return error;
- to_nodeid = r->res_nodeid;
-
error = create_message(r, lkb, to_nodeid, mstype, &ms, &mh);
if (error)
goto fail;
@@ -2951,12 +3037,12 @@ static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb)
struct dlm_mhandle *mh;
int to_nodeid, error;
- error = add_to_waiters(lkb, DLM_MSG_LOOKUP);
+ to_nodeid = dlm_dir_nodeid(r);
+
+ error = add_to_waiters(lkb, DLM_MSG_LOOKUP, to_nodeid);
if (error)
return error;
- to_nodeid = dlm_dir_nodeid(r);
-
error = create_message(r, NULL, to_nodeid, DLM_MSG_LOOKUP, &ms, &mh);
if (error)
goto fail;