From b81a3ddc3207dd832bd236f2ff20d409a0aee0b4 Mon Sep 17 00:00:00 2001 From: Tim Chase Date: Tue, 31 Jan 2017 16:19:08 -0600 Subject: Update deadman operation to better align with upstream OpenZFS The deadman in ZoL didn't behave quite as it did in upstream OpenZFS. In addition to the 2 purposes for which OpenZFS used the zfs_deadman_synctime_ms parameter, ZoL also used it to determine how frequently the deadman would fire once it has been triggered. This patch adds the zfs_deadman_checktime_ms parameter to control how frequently the subsequent checks are performed. The deadman is now disabled for suspended pools. As had been the case, unlike upstream OpenZFS, ZoL will not panic when a hung IO is detected. The module parameter documentation has been upated to include the new parameter and to better describe the operation of the deadmen. Reviewed-by: Brian Behlendorf Reviewed-by: George Melikov Signed-off-by: Tim Chase Closes #5695 --- module/zfs/spa_misc.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'module/zfs') diff --git a/module/zfs/spa_misc.c b/module/zfs/spa_misc.c index fa9bdd7b8..c39c137e6 100644 --- a/module/zfs/spa_misc.c +++ b/module/zfs/spa_misc.c @@ -297,6 +297,12 @@ int zfs_free_leak_on_eio = B_FALSE; */ unsigned long zfs_deadman_synctime_ms = 1000000ULL; +/* + * Check time in milliseconds. This defines the frequency at which we check + * for hung I/O. + */ +unsigned long zfs_deadman_checktime_ms = 5000ULL; + /* * By default the deadman is enabled. */ @@ -524,6 +530,10 @@ spa_deadman(void *arg) { spa_t *spa = arg; + /* Disable the deadman if the pool is suspended. */ + if (spa_suspended(spa)) + return; + zfs_dbgmsg("slow spa_sync: started %llu seconds ago, calls %llu", (gethrtime() - spa->spa_sync_starttime) / NANOSEC, ++spa->spa_deadman_calls); @@ -532,7 +542,7 @@ spa_deadman(void *arg) spa->spa_deadman_tqid = taskq_dispatch_delay(system_delay_taskq, spa_deadman, spa, TQ_SLEEP, ddi_get_lbolt() + - NSEC_TO_TICK(spa->spa_deadman_synctime)); + MSEC_TO_TICK(zfs_deadman_checktime_ms)); } /* @@ -2114,6 +2124,10 @@ MODULE_PARM_DESC(zfs_free_leak_on_eio, module_param(zfs_deadman_synctime_ms, ulong, 0644); MODULE_PARM_DESC(zfs_deadman_synctime_ms, "Expiration time in milliseconds"); +module_param(zfs_deadman_checktime_ms, ulong, 0644); +MODULE_PARM_DESC(zfs_deadman_checktime_ms, + "Dead I/O check interval in milliseconds"); + module_param(zfs_deadman_enabled, int, 0644); MODULE_PARM_DESC(zfs_deadman_enabled, "Enable deadman timer"); -- cgit v1.2.3