Fix zfs_txg_timeout module parameter

Allow the zfs_txg_timeout variable to be dynamically tuned at run time. By pulling it down out of the variable declaration it will be evaluted each time through the loop. The zfs_txg_timeout variable is now declared extern in a the common sys/txg.h header rather than locally in dsl_scan.c. This prevents potential type mismatches if the global variable needs to be used elsewhere. Move the module_param() code in to the same source file where zfs_txg_timeout is declared. This is the most logical location. Signed-off-by: Brian Behlendorf <[email protected]>
openzfs · Oct 11, 2012 · 87d98ef · 87d98ef
1 parent 7df05a4
commit 87d98ef
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Showing 3 changed files with 9 additions and 6 deletions.
diff --git a/include/sys/txg.h b/include/sys/txg.h
@@ -130,6 +130,9 @@ extern int txg_list_member(txg_list_t *tl, void *p, uint64_t txg);
 extern void *txg_list_head(txg_list_t *tl, uint64_t txg);
 extern void *txg_list_next(txg_list_t *tl, void *p, uint64_t txg);
 
+/* Global tuning */
+extern int zfs_txg_timeout;
+
 #ifdef	__cplusplus
 }
 #endif

diff --git a/module/zfs/dsl_scan.c b/module/zfs/dsl_scan.c
@@ -71,8 +71,6 @@ int dsl_scan_delay_completion = B_FALSE; /* set to delay scan completion */
 	((scn)->scn_phys.scn_func == POOL_SCAN_SCRUB || \
 	(scn)->scn_phys.scn_func == POOL_SCAN_RESILVER)
 
-extern int zfs_txg_timeout;
-
 /* the order has to match pool_scan_type */
 static scan_cb_t *scan_funcs[POOL_SCAN_FUNCS] = {
 	NULL,
@@ -1813,7 +1811,4 @@ MODULE_PARM_DESC(zfs_no_scrub_io, "Set to disable scrub I/O");
 
 module_param(zfs_no_scrub_prefetch, int, 0644);
 MODULE_PARM_DESC(zfs_no_scrub_prefetch, "Set to disable scrub prefetching");
-
-module_param(zfs_txg_timeout, int, 0644);
-MODULE_PARM_DESC(zfs_txg_timeout, "Max seconds worth of delta per txg");
 #endif
diff --git a/module/zfs/txg.c b/module/zfs/txg.c
@@ -395,9 +395,11 @@ txg_sync_thread(dsl_pool_t *dp)
 
 	start = delta = 0;
 	for (;;) {
-		uint64_t timer, timeout = zfs_txg_timeout * hz;
+		uint64_t timer, timeout;
 		uint64_t txg;
 
+		timeout = zfs_txg_timeout * hz;
+
 		/*
 		 * We sync when we're scanning, there's someone waiting
 		 * on us, or the quiesce thread has handed off a txg to
@@ -773,4 +775,7 @@ EXPORT_SYMBOL(txg_wait_open);
 EXPORT_SYMBOL(txg_wait_callbacks);
 EXPORT_SYMBOL(txg_stalled);
 EXPORT_SYMBOL(txg_sync_waiting);
+
+module_param(zfs_txg_timeout, int, 0644);
+MODULE_PARM_DESC(zfs_txg_timeout, "Max seconds worth of delta per txg");
 #endif