X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Farc.c;h=eb5304a82a8cfb592758fcb585ef78ef87c8a77d;hb=da88a7fbe8876437c25f1006f91ca5595659b8d2;hp=9ca8ad17d75d37d4a4d11f138ac9cc0b99133ebd;hpb=7cb67b45f33fd7a61af24c675c7347eb5264b38c;p=zfs.git

diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index 9ca8ad1..eb5304a 100644
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -180,6 +180,7 @@ unsigned long zfs_arc_meta_limit = 0;
 int zfs_arc_grow_retry = 0;
 int zfs_arc_shrink_shift = 0;
 int zfs_arc_p_min_shift = 0;
+int zfs_arc_reduce_dnlc_percent = 0;
 
 /*
  * Note that buffers can be in one of 6 states:
@@ -2084,14 +2085,16 @@ arc_kmem_reap_now(arc_reclaim_strategy_t strat)
 	kmem_cache_t		*prev_data_cache = NULL;
 	extern kmem_cache_t	*zio_buf_cache[];
 	extern kmem_cache_t	*zio_data_buf_cache[];
-
 #ifdef _KERNEL
-	if (arc_meta_used >= arc_meta_limit) {
+	int			retry = 0;
+
+	while ((arc_meta_used >= arc_meta_limit) && (retry < 10)) {
 		/*
 		 * We are exceeding our meta-data cache limit.
 		 * Purge some DNLC entries to release holds on meta-data.
 		 */
 		dnlc_reduce_cache((void *)(uintptr_t)arc_reduce_dnlc_percent);
+		retry++;
 	}
 #if defined(__i386)
 	/*
@@ -2157,6 +2160,10 @@ arc_reclaim_thread(void)
 			arc_no_grow = FALSE;
 		}
 
+		/* Keep meta data usage within limits */
+		if (arc_meta_used >= arc_meta_limit)
+			arc_kmem_reap_now(ARC_RECLAIM_CONS);
+
 		arc_adjust();
 
 		if (arc_eviction_list != NULL)
@@ -2189,15 +2196,20 @@ SPL_SHRINKER_CALLBACK_PROTO(arc_shrinker_func, cb, nr_to_scan, gfp_mask)
 	arc_reclaim_strategy_t strategy;
 	int arc_reclaim;
 
-	/* Not allowed to perform filesystem reclaim */
-	if (!(gfp_mask & __GFP_FS))
-		return (-1);
-
 	/* Return number of reclaimable pages based on arc_shrink_shift */
-	arc_reclaim = btop((arc_size - arc_c_min)) >> arc_shrink_shift;
+	arc_reclaim = MAX(btop(((int64_t)arc_size - (int64_t)arc_c_min))
+	    >> arc_shrink_shift, 0);
 	if (nr_to_scan == 0)
 		return (arc_reclaim);
 
+	/* Prevent reclaim below arc_c_min */
+	if (arc_reclaim <= 0)
+		return (-1);
+
+	/* Not allowed to perform filesystem reclaim */
+	if (!(gfp_mask & __GFP_FS))
+		return (-1);
+
 	/* Reclaim in progress */
 	if (mutex_tryenter(&arc_reclaim_thr_lock) == 0)
 		return (-1);
@@ -2211,7 +2223,8 @@ SPL_SHRINKER_CALLBACK_PROTO(arc_shrinker_func, cb, nr_to_scan, gfp_mask)
 	}
 
 	arc_kmem_reap_now(strategy);
-	arc_reclaim = btop((arc_size - arc_c_min)) >> arc_shrink_shift;
+	arc_reclaim = MAX(btop(((int64_t)arc_size - (int64_t)arc_c_min))
+	    >> arc_shrink_shift, 0);
 	mutex_exit(&arc_reclaim_thr_lock);
 
 	return (arc_reclaim);
@@ -3583,6 +3596,9 @@ arc_init(void)
 	if (zfs_arc_p_min_shift > 0)
 		arc_p_min_shift = zfs_arc_p_min_shift;
 
+	if (zfs_arc_reduce_dnlc_percent > 0)
+		arc_reduce_dnlc_percent = zfs_arc_reduce_dnlc_percent;
+
 	/* if kmem_flags are set, lets try to use less memory */
 	if (kmem_debugging())
 		arc_c = arc_c / 2;
@@ -4757,12 +4773,25 @@ EXPORT_SYMBOL(arc_read);
 EXPORT_SYMBOL(arc_buf_remove_ref);
 EXPORT_SYMBOL(arc_getbuf_func);
 
-module_param(zfs_arc_min, ulong, 0644);
-MODULE_PARM_DESC(zfs_arc_min, "Minimum arc size");
+module_param(zfs_arc_min, ulong, 0444);
+MODULE_PARM_DESC(zfs_arc_min, "Min arc size");
 
-module_param(zfs_arc_max, ulong, 0644);
-MODULE_PARM_DESC(zfs_arc_max, "Maximum arc size");
+module_param(zfs_arc_max, ulong, 0444);
+MODULE_PARM_DESC(zfs_arc_max, "Max arc size");
 
-module_param(zfs_arc_meta_limit, ulong, 0644);
+module_param(zfs_arc_meta_limit, ulong, 0444);
 MODULE_PARM_DESC(zfs_arc_meta_limit, "Meta limit for arc size");
+
+module_param(zfs_arc_reduce_dnlc_percent, int, 0444);
+MODULE_PARM_DESC(zfs_arc_reduce_dnlc_percent, "Meta reclaim percentage");
+
+module_param(zfs_arc_grow_retry, int, 0444);
+MODULE_PARM_DESC(zfs_arc_grow_retry, "Seconds before growing arc size");
+
+module_param(zfs_arc_shrink_shift, int, 0444);
+MODULE_PARM_DESC(zfs_arc_shrink_shift, "log2(fraction of arc to reclaim)");
+
+module_param(zfs_arc_p_min_shift, int, 0444);
+MODULE_PARM_DESC(zfs_arc_p_min_shift, "arc_c shift to calc min/max arc_p");
+
 #endif