X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Ftxg.c;h=1cb3cb61c43abbc7cde92383d444303b66d5d7a8;hb=9e11c7eee232b73600c2590c8c3326b2725daba5;hp=5afb139ddfb0b87710bd2805326acf06ad0943a8;hpb=54a179e7b80413bd48cd2cd259110fb493d0215e;p=zfs.git

diff --git a/module/zfs/txg.c b/module/zfs/txg.c
index 5afb139..1cb3cb6 100644
--- a/module/zfs/txg.c
+++ b/module/zfs/txg.c
@@ -166,10 +166,10 @@ txg_thread_wait(tx_state_t *tx, callb_cpr_t *cpr, kcondvar_t *cv, uint64_t time)
 	CALLB_CPR_SAFE_BEGIN(cpr);
 
 	if (time)
-		(void) cv_timedwait(cv, &tx->tx_sync_lock,
+		(void) cv_timedwait_interruptible(cv, &tx->tx_sync_lock,
 		    ddi_get_lbolt() + time);
 	else
-		cv_wait(cv, &tx->tx_sync_lock);
+		cv_wait_interruptible(cv, &tx->tx_sync_lock);
 
 	CALLB_CPR_SAFE_END(cpr, &tx->tx_sync_lock);
 }
@@ -218,9 +218,19 @@ uint64_t
 txg_hold_open(dsl_pool_t *dp, txg_handle_t *th)
 {
 	tx_state_t *tx = &dp->dp_tx;
-	tx_cpu_t *tc = &tx->tx_cpu[CPU_SEQID];
+	tx_cpu_t *tc;
 	uint64_t txg;
 
+	/*
+	 * It appears the processor id is simply used as a "random"
+	 * number to index into the array, and there isn't any other
+	 * significance to the chosen tx_cpu. Because.. Why not use
+	 * the current cpu to index into the array?
+	 */
+	kpreempt_disable();
+	tc = &tx->tx_cpu[CPU_SEQID];
+	kpreempt_enable();
+
 	mutex_enter(&tc->tc_lock);
 
 	txg = tx->tx_open_txg;
@@ -372,6 +382,19 @@ txg_sync_thread(dsl_pool_t *dp)
 	callb_cpr_t cpr;
 	uint64_t start, delta;
 
+#ifdef _KERNEL
+	/*
+	 * Disable the normal reclaim path for the txg_sync thread.  This
+	 * ensures the thread will never enter dmu_tx_assign() which can
+	 * otherwise occur due to direct reclaim.  If this is allowed to
+	 * happen the system can deadlock.  Direct reclaim call path:
+	 *
+	 *   ->shrink_icache_memory->prune_icache->dispose_list->
+	 *   clear_inode->zpl_clear_inode->zfs_inactive->dmu_tx_assign
+	 */
+	current->flags |= PF_MEMALLOC;
+#endif /* _KERNEL */
+
 	txg_thread_enter(tx, &cpr);
 
 	start = delta = 0;
@@ -493,7 +516,7 @@ void
 txg_delay(dsl_pool_t *dp, uint64_t txg, int ticks)
 {
 	tx_state_t *tx = &dp->dp_tx;
-	int timeout = ddi_get_lbolt() + ticks;
+	clock_t timeout = ddi_get_lbolt() + ticks;
 
 	/* don't delay if this txg could transition to quiesing immediately */
 	if (tx->tx_open_txg > txg ||
@@ -511,6 +534,8 @@ txg_delay(dsl_pool_t *dp, uint64_t txg, int ticks)
 		(void) cv_timedwait(&tx->tx_quiesce_more_cv, &tx->tx_sync_lock,
 		    timeout);
 
+	DMU_TX_STAT_BUMP(dmu_tx_delay);
+
 	mutex_exit(&tx->tx_sync_lock);
 }