svn commit: r302265 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs
Steven Hartland
smh at FreeBSD.org
Wed Jun 29 07:55:46 UTC 2016
Author: smh
Date: Wed Jun 29 07:55:45 2016
New Revision: 302265
URL: https://svnweb.freebsd.org/changeset/base/302265
Log:
Allow ZFS ARC min / max to be tuned at runtime
Prior to this change ZFS ARC min / max could only be changed using
boot time tunables, this allows the values to be tuned at runtime
using the sysctls:
* vfs.zfs.arc_max
* vfs.zfs.arc_min
When adjusting ZFS ARC minimum the memory used will only reduce
to the new minimum given memory pressure.
Reviewed by: allanjude
Approved by: re (gjb)
MFC after: 2 weeks
Relnotes: yes
Sponsored by: Multiplay
Differential Revision: https://reviews.freebsd.org/D5907
Modified:
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_pool.c
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Wed Jun 29 07:00:15 2016 (r302264)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Wed Jun 29 07:55:45 2016 (r302265)
@@ -238,10 +238,15 @@ int zfs_disable_dup_eviction = 0;
uint64_t zfs_arc_average_blocksize = 8 * 1024; /* 8KB */
u_int zfs_arc_free_target = 0;
+/* Absolute min for arc min / max is 16MB. */
+static uint64_t arc_abs_min = 16 << 20;
+
static int sysctl_vfs_zfs_arc_free_target(SYSCTL_HANDLER_ARGS);
static int sysctl_vfs_zfs_arc_meta_limit(SYSCTL_HANDLER_ARGS);
+static int sysctl_vfs_zfs_arc_max(SYSCTL_HANDLER_ARGS);
+static int sysctl_vfs_zfs_arc_min(SYSCTL_HANDLER_ARGS);
-#ifdef _KERNEL
+#if defined(__FreeBSD__) && defined(_KERNEL)
static void
arc_free_target_init(void *unused __unused)
{
@@ -255,10 +260,10 @@ TUNABLE_QUAD("vfs.zfs.arc_meta_limit", &
TUNABLE_QUAD("vfs.zfs.arc_meta_min", &zfs_arc_meta_min);
TUNABLE_INT("vfs.zfs.arc_shrink_shift", &zfs_arc_shrink_shift);
SYSCTL_DECL(_vfs_zfs);
-SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, arc_max, CTLFLAG_RDTUN, &zfs_arc_max, 0,
- "Maximum ARC size");
-SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, arc_min, CTLFLAG_RDTUN, &zfs_arc_min, 0,
- "Minimum ARC size");
+SYSCTL_PROC(_vfs_zfs, OID_AUTO, arc_max, CTLTYPE_U64 | CTLFLAG_RWTUN,
+ 0, sizeof(uint64_t), sysctl_vfs_zfs_arc_max, "QU", "Maximum ARC size");
+SYSCTL_PROC(_vfs_zfs, OID_AUTO, arc_min, CTLTYPE_U64 | CTLFLAG_RWTUN,
+ 0, sizeof(uint64_t), sysctl_vfs_zfs_arc_min, "QU", "Minimum ARC size");
SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, arc_average_blocksize, CTLFLAG_RDTUN,
&zfs_arc_average_blocksize, 0,
"ARC average blocksize");
@@ -884,7 +889,7 @@ struct arc_buf_hdr {
l1arc_buf_hdr_t b_l1hdr;
};
-#ifdef _KERNEL
+#if defined(__FreeBSD__) && defined(_KERNEL)
static int
sysctl_vfs_zfs_arc_meta_limit(SYSCTL_HANDLER_ARGS)
{
@@ -902,6 +907,70 @@ sysctl_vfs_zfs_arc_meta_limit(SYSCTL_HAN
arc_meta_limit = val;
return (0);
}
+
+static int
+sysctl_vfs_zfs_arc_max(SYSCTL_HANDLER_ARGS)
+{
+ uint64_t val;
+ int err;
+
+ val = zfs_arc_max;
+ err = sysctl_handle_64(oidp, &val, 0, req);
+ if (err != 0 || req->newptr == NULL)
+ return (err);
+
+ if (val < arc_abs_min || val > kmem_size())
+ return (EINVAL);
+ if (val < arc_c_min)
+ return (EINVAL);
+ if (zfs_arc_meta_limit > 0 && val < zfs_arc_meta_limit)
+ return (EINVAL);
+
+ arc_c_max = val;
+
+ arc_c = arc_c_max;
+ arc_p = (arc_c >> 1);
+
+ if (zfs_arc_meta_limit == 0) {
+ /* limit meta-data to 1/4 of the arc capacity */
+ arc_meta_limit = arc_c_max / 4;
+ }
+
+ /* if kmem_flags are set, lets try to use less memory */
+ if (kmem_debugging())
+ arc_c = arc_c / 2;
+
+ zfs_arc_max = arc_c;
+
+ return (0);
+}
+
+static int
+sysctl_vfs_zfs_arc_min(SYSCTL_HANDLER_ARGS)
+{
+ uint64_t val;
+ int err;
+
+ val = zfs_arc_min;
+ err = sysctl_handle_64(oidp, &val, 0, req);
+ if (err != 0 || req->newptr == NULL)
+ return (err);
+
+ if (val < arc_abs_min || val > arc_c_max)
+ return (EINVAL);
+
+ arc_c_min = val;
+
+ if (zfs_arc_meta_min == 0)
+ arc_meta_min = arc_c_min / 2;
+
+ if (arc_c < arc_c_min)
+ arc_c = arc_c_min;
+
+ zfs_arc_min = arc_c_min;
+
+ return (0);
+}
#endif
static arc_buf_t *arc_eviction_list;
@@ -5385,8 +5454,8 @@ arc_init(void)
arc_c = MIN(arc_c, vmem_size(heap_arena, VMEM_ALLOC | VMEM_FREE) / 8);
#endif
#endif /* illumos */
- /* set min cache to 1/32 of all memory, or 16MB, whichever is more */
- arc_c_min = MAX(arc_c / 4, 16 << 20);
+ /* set min cache to 1/32 of all memory, or arc_abs_min, whichever is more */
+ arc_c_min = MAX(arc_c / 4, arc_abs_min);
/* set max to 1/2 of all memory, or all but 1GB, whichever is more */
if (arc_c * 8 >= 1 << 30)
arc_c_max = (arc_c * 8) - (1 << 30);
@@ -5407,11 +5476,11 @@ arc_init(void)
#ifdef _KERNEL
/*
* Allow the tunables to override our calculations if they are
- * reasonable (ie. over 16MB)
+ * reasonable.
*/
- if (zfs_arc_max > 16 << 20 && zfs_arc_max < kmem_size())
+ if (zfs_arc_max > arc_abs_min && zfs_arc_max < kmem_size())
arc_c_max = zfs_arc_max;
- if (zfs_arc_min > 16 << 20 && zfs_arc_min <= arc_c_max)
+ if (zfs_arc_min > arc_abs_min && zfs_arc_min <= arc_c_max)
arc_c_min = zfs_arc_min;
#endif
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_pool.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_pool.c Wed Jun 29 07:00:15 2016 (r302264)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_pool.c Wed Jun 29 07:55:45 2016 (r302265)
@@ -49,8 +49,8 @@
#include <sys/dsl_userhold.h>
#if defined(__FreeBSD__) && defined(_KERNEL)
-#include <sys/sysctl.h>
#include <sys/types.h>
+#include <sys/sysctl.h>
#endif
/*
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