svn commit: r275549 - vendor-sys/illumos/dist/uts/common/fs/zfs
Xin LI
delphij at FreeBSD.org
Sat Dec 6 00:45:28 UTC 2014
Author: delphij
Date: Sat Dec 6 00:45:27 2014
New Revision: 275549
URL: https://svnweb.freebsd.org/changeset/base/275549
Log:
5368 ARC should cache more metadata
Reviewed by: Alex Reece <alex.reece at delphix.com>
Reviewed by: Christopher Siden <christopher.siden at delphix.com>
Reviewed by: George Wilson <george.wilson at delphix.com>
Reviewed by: Richard Elling <richard.elling at richardelling.com>
Approved by: Dan McDonald <danmcd at omniti.com>
Author: Matthew Ahrens <mahrens at delphix.com>
illumos/illumos-gate at 3a5286a1cffceafcd8cf79c4156fad605129bf50
Modified:
vendor-sys/illumos/dist/uts/common/fs/zfs/arc.c
Modified: vendor-sys/illumos/dist/uts/common/fs/zfs/arc.c
==============================================================================
--- vendor-sys/illumos/dist/uts/common/fs/zfs/arc.c Sat Dec 6 00:42:30 2014 (r275548)
+++ vendor-sys/illumos/dist/uts/common/fs/zfs/arc.c Sat Dec 6 00:45:27 2014 (r275549)
@@ -196,6 +196,7 @@ static boolean_t arc_warm;
uint64_t zfs_arc_max;
uint64_t zfs_arc_min;
uint64_t zfs_arc_meta_limit = 0;
+uint64_t zfs_arc_meta_min = 0;
int zfs_arc_grow_retry = 0;
int zfs_arc_shrink_shift = 0;
int zfs_arc_p_min_shift = 0;
@@ -324,6 +325,7 @@ typedef struct arc_stats {
kstat_named_t arcstat_meta_used;
kstat_named_t arcstat_meta_limit;
kstat_named_t arcstat_meta_max;
+ kstat_named_t arcstat_meta_min;
} arc_stats_t;
static arc_stats_t arc_stats = {
@@ -389,7 +391,8 @@ static arc_stats_t arc_stats = {
{ "duplicate_reads", KSTAT_DATA_UINT64 },
{ "arc_meta_used", KSTAT_DATA_UINT64 },
{ "arc_meta_limit", KSTAT_DATA_UINT64 },
- { "arc_meta_max", KSTAT_DATA_UINT64 }
+ { "arc_meta_max", KSTAT_DATA_UINT64 },
+ { "arc_meta_min", KSTAT_DATA_UINT64 }
};
#define ARCSTAT(stat) (arc_stats.stat.value.ui64)
@@ -452,6 +455,7 @@ static arc_state_t *arc_l2c_only;
#define arc_c_min ARCSTAT(arcstat_c_min) /* min target cache size */
#define arc_c_max ARCSTAT(arcstat_c_max) /* max target cache size */
#define arc_meta_limit ARCSTAT(arcstat_meta_limit) /* max size for metadata */
+#define arc_meta_min ARCSTAT(arcstat_meta_min) /* min size for metadata */
#define arc_meta_used ARCSTAT(arcstat_meta_used) /* size of metadata */
#define arc_meta_max ARCSTAT(arcstat_meta_max) /* max size of metadata */
@@ -1779,7 +1783,6 @@ arc_evict(arc_state_t *state, uint64_t s
arc_state_t *evicted_state;
uint64_t bytes_evicted = 0, skipped = 0, missed = 0;
arc_buf_hdr_t *ab, *ab_prev = NULL;
- list_t *list = &state->arcs_list[type];
kmutex_t *hash_lock;
boolean_t have_lock;
void *stolen = NULL;
@@ -1793,6 +1796,50 @@ arc_evict(arc_state_t *state, uint64_t s
mutex_enter(&state->arcs_mtx);
mutex_enter(&evicted_state->arcs_mtx);
+ /*
+ * Decide which "type" (data vs metadata) to recycle from.
+ *
+ * If we are over the metadata limit, recycle from metadata.
+ * If we are under the metadata minimum, recycle from data.
+ * Otherwise, recycle from whichever type has the oldest (least
+ * recently accessed) header.
+ */
+ if (recycle) {
+ arc_buf_hdr_t *data_hdr =
+ list_tail(&state->arcs_list[ARC_BUFC_DATA]);
+ arc_buf_hdr_t *metadata_hdr =
+ list_tail(&state->arcs_list[ARC_BUFC_METADATA]);
+ arc_buf_contents_t realtype;
+ if (data_hdr == NULL) {
+ realtype = ARC_BUFC_METADATA;
+ } else if (metadata_hdr == NULL) {
+ realtype = ARC_BUFC_DATA;
+ } else if (arc_meta_used >= arc_meta_limit) {
+ realtype = ARC_BUFC_METADATA;
+ } else if (arc_meta_used <= arc_meta_min) {
+ realtype = ARC_BUFC_DATA;
+ } else {
+ if (data_hdr->b_arc_access <
+ metadata_hdr->b_arc_access) {
+ realtype = ARC_BUFC_DATA;
+ } else {
+ realtype = ARC_BUFC_METADATA;
+ }
+ }
+ if (realtype != type) {
+ /*
+ * If we want to evict from a different list,
+ * we can not recycle, because DATA vs METADATA
+ * buffers are segregated into different kmem
+ * caches (and vmem arenas).
+ */
+ type = realtype;
+ recycle = B_FALSE;
+ }
+ }
+
+ list_t *list = &state->arcs_list[type];
+
for (ab = list_tail(list); ab; ab = ab_prev) {
ab_prev = list_prev(list, ab);
/* prefetch buffers have a minimum lifespan */
@@ -3755,6 +3802,12 @@ arc_init(void)
if (arc_c_min < arc_meta_limit / 2 && zfs_arc_min == 0)
arc_c_min = arc_meta_limit / 2;
+ if (zfs_arc_meta_min > 0) {
+ arc_meta_min = zfs_arc_meta_min;
+ } else {
+ arc_meta_min = arc_c_min / 2;
+ }
+
if (zfs_arc_grow_retry > 0)
arc_grow_retry = zfs_arc_grow_retry;
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