Author: smh
Date: Fri Oct 10 00:12:16 2014
New Revision: 272875
URL: https://svnweb.freebsd.org/changeset/base/272875
Log:
MFC r270759:
Refactor ZFS ARC reclaim logic to be more VM cooperative
MFC r270861:
Ensure that ZFS ARC free memory checks include cached pages
MFC r272483:
Refactor ZFS ARC reclaim checks and limits
Sponsored by: Multiplay
Modified:
stable/10/sys/cddl/compat/opensolaris/kern/opensolaris_kmem.c
stable/10/sys/cddl/compat/opensolaris/sys/kmem.h
stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
stable/10/sys/vm/vm_pageout.c
Directory Properties:
stable/10/ (props changed)
Modified: stable/10/sys/cddl/compat/opensolaris/kern/opensolaris_kmem.c
==============================================================================
--- stable/10/sys/cddl/compat/opensolaris/kern/opensolaris_kmem.c Thu Oct
9 23:52:33 2014 (r272874)
+++ stable/10/sys/cddl/compat/opensolaris/kern/opensolaris_kmem.c Fri Oct
10 00:12:16 2014 (r272875)
@@ -133,13 +133,6 @@ kmem_size(void)
return (kmem_size_val);
}
-uint64_t
-kmem_used(void)
-{
-
- return (vmem_size(kmem_arena, VMEM_ALLOC));
-}
-
static int
kmem_std_constructor(void *mem, int size __unused, void *private, int flags)
{
Modified: stable/10/sys/cddl/compat/opensolaris/sys/kmem.h
==============================================================================
--- stable/10/sys/cddl/compat/opensolaris/sys/kmem.h Thu Oct 9 23:52:33
2014 (r272874)
+++ stable/10/sys/cddl/compat/opensolaris/sys/kmem.h Fri Oct 10 00:12:16
2014 (r272875)
@@ -66,7 +66,6 @@ typedef struct kmem_cache {
void *zfs_kmem_alloc(size_t size, int kmflags);
void zfs_kmem_free(void *buf, size_t size);
uint64_t kmem_size(void);
-uint64_t kmem_used(void);
kmem_cache_t *kmem_cache_create(char *name, size_t bufsize, size_t align,
int (*constructor)(void *, void *, int), void (*destructor)(void *, void
*),
void (*reclaim)(void *) __unused, void *private, vmem_t *vmp, int cflags);
@@ -78,6 +77,9 @@ void kmem_reap(void);
int kmem_debugging(void);
void *calloc(size_t n, size_t s);
+#define freemem (cnt.v_free_count +
cnt.v_cache_count)
+#define minfree cnt.v_free_min
+#define heap_arena kmem_arena
#define kmem_alloc(size, kmflags) zfs_kmem_alloc((size),
(kmflags))
#define kmem_zalloc(size, kmflags) zfs_kmem_alloc((size),
(kmflags) | M_ZERO)
#define kmem_free(buf, size) zfs_kmem_free((buf), (size))
Modified: stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
==============================================================================
--- stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Thu Oct
9 23:52:33 2014 (r272874)
+++ stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Fri Oct
10 00:12:16 2014 (r272875)
@@ -138,6 +138,7 @@
#include <sys/sdt.h>
#include <vm/vm_pageout.h>
+#include <machine/vmparam.h>
#ifdef illumos
#ifndef _KERNEL
@@ -193,9 +194,6 @@ extern int zfs_prefetch_disable;
*/
static boolean_t arc_warm;
-/*
- * These tunables are for performance analysis.
- */
uint64_t zfs_arc_max;
uint64_t zfs_arc_min;
uint64_t zfs_arc_meta_limit = 0;
@@ -204,6 +202,19 @@ int zfs_arc_shrink_shift = 0;
int zfs_arc_p_min_shift = 0;
int zfs_disable_dup_eviction = 0;
uint64_t zfs_arc_average_blocksize = 8 * 1024; /* 8KB */
+u_int zfs_arc_free_target = 0;
+
+static int sysctl_vfs_zfs_arc_free_target(SYSCTL_HANDLER_ARGS);
+
+#ifdef _KERNEL
+static void
+arc_free_target_init(void *unused __unused)
+{
+
+ zfs_arc_free_target = vm_pageout_wakeup_thresh;
+}
+SYSINIT(arc_free_target_init, SI_SUB_KTHREAD_PAGE, SI_ORDER_ANY,
+ arc_free_target_init, NULL);
TUNABLE_QUAD("vfs.zfs.arc_max", &zfs_arc_max);
TUNABLE_QUAD("vfs.zfs.arc_min", &zfs_arc_min);
@@ -217,6 +228,36 @@ SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, arc_min
SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, arc_average_blocksize, CTLFLAG_RDTUN,
&zfs_arc_average_blocksize, 0,
"ARC average blocksize");
+/*
+ * We don't have a tunable for arc_free_target due to the dependency on
+ * pagedaemon initialisation.
+ */
+SYSCTL_PROC(_vfs_zfs, OID_AUTO, arc_free_target,
+ CTLTYPE_UINT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, sizeof(u_int),
+ sysctl_vfs_zfs_arc_free_target, "IU",
+ "Desired number of free pages below which ARC triggers reclaim");
+
+static int
+sysctl_vfs_zfs_arc_free_target(SYSCTL_HANDLER_ARGS)
+{
+ u_int val;
+ int err;
+
+ val = zfs_arc_free_target;
+ err = sysctl_handle_int(oidp, &val, 0, req);
+ if (err != 0 || req->newptr == NULL)
+ return (err);
+
+ if (val < minfree)
+ return (EINVAL);
+ if (val > cnt.v_page_count)
+ return (EINVAL);
+
+ zfs_arc_free_target = val;
+
+ return (0);
+}
+#endif
/*
* Note that buffers can be in one of 6 states:
@@ -2421,9 +2462,12 @@ arc_flush(spa_t *spa)
void
arc_shrink(void)
{
+
if (arc_c > arc_c_min) {
uint64_t to_free;
+ DTRACE_PROBE4(arc__shrink, uint64_t, arc_c, uint64_t,
+ arc_c_min, uint64_t, arc_p, uint64_t, to_free);
#ifdef _KERNEL
to_free = arc_c >> arc_shrink_shift;
#else
@@ -2439,12 +2483,19 @@ arc_shrink(void)
arc_c = MAX(arc_size, arc_c_min);
if (arc_p > arc_c)
arc_p = (arc_c >> 1);
+
+ DTRACE_PROBE2(arc__shrunk, uint64_t, arc_c, uint64_t,
+ arc_p);
+
ASSERT(arc_c >= arc_c_min);
ASSERT((int64_t)arc_p >= 0);
}
- if (arc_size > arc_c)
+ if (arc_size > arc_c) {
+ DTRACE_PROBE2(arc__shrink_adjust, uint64_t, arc_size,
+ uint64_t, arc_c);
arc_adjust();
+ }
}
static int needfree = 0;
@@ -2455,15 +2506,20 @@ arc_reclaim_needed(void)
#ifdef _KERNEL
- if (needfree)
+ if (needfree) {
+ DTRACE_PROBE(arc__reclaim_needfree);
return (1);
+ }
/*
* Cooperate with pagedaemon when it's time for it to scan
* and reclaim some pages.
*/
- if (vm_paging_needed())
+ if (freemem < zfs_arc_free_target) {
+ DTRACE_PROBE2(arc__reclaim_freemem, uint64_t,
+ freemem, uint64_t, zfs_arc_free_target);
return (1);
+ }
#ifdef sun
/*
@@ -2491,7 +2547,18 @@ arc_reclaim_needed(void)
if (availrmem < swapfs_minfree + swapfs_reserve + extra)
return (1);
-#if defined(__i386)
+ /*
+ * Check that we have enough availrmem that memory locking (e.g., via
+ * mlock(3C) or memcntl(2)) can still succeed. (pages_pp_maximum
+ * stores the number of pages that cannot be locked; when availrmem
+ * drops below pages_pp_maximum, page locking mechanisms such as
+ * page_pp_lock() will fail.)
+ */
+ if (availrmem <= pages_pp_maximum)
+ return (1);
+
+#endif /* sun */
+#if defined(__i386) || !defined(UMA_MD_SMALL_ALLOC)
/*
* If we're on an i386 platform, it's possible that we'll exhaust the
* kernel heap space before we ever run out of available physical
@@ -2503,32 +2570,49 @@ arc_reclaim_needed(void)
* heap is allocated. (Or, in the calculation, if less than 1/4th is
* free)
*/
- if (btop(vmem_size(heap_arena, VMEM_FREE)) <
- (btop(vmem_size(heap_arena, VMEM_FREE | VMEM_ALLOC)) >> 2))
+ if (vmem_size(heap_arena, VMEM_FREE) <
+ (vmem_size(heap_arena, VMEM_FREE | VMEM_ALLOC) >> 2)) {
+ DTRACE_PROBE2(arc__reclaim_used, uint64_t,
+ vmem_size(heap_arena, VMEM_FREE), uint64_t,
+ (vmem_size(heap_arena, VMEM_FREE | VMEM_ALLOC)) >> 2);
return (1);
+ }
#endif
-#else /* !sun */
- if (kmem_used() > (kmem_size() * 3) / 4)
+#ifdef sun
+ /*
+ * If zio data pages are being allocated out of a separate heap segment,
+ * then enforce that the size of available vmem for this arena remains
+ * above about 1/16th free.
+ *
+ * Note: The 1/16th arena free requirement was put in place
+ * to aggressively evict memory from the arc in order to avoid
+ * memory fragmentation issues.
+ */
+ if (zio_arena != NULL &&
+ vmem_size(zio_arena, VMEM_FREE) <
+ (vmem_size(zio_arena, VMEM_ALLOC) >> 4))
return (1);
#endif /* sun */
-
-#else
+#else /* _KERNEL */
if (spa_get_random(100) == 0)
return (1);
-#endif
+#endif /* _KERNEL */
+ DTRACE_PROBE(arc__reclaim_no);
+
return (0);
}
extern kmem_cache_t *zio_buf_cache[];
extern kmem_cache_t *zio_data_buf_cache[];
-static void
+static void __noinline
arc_kmem_reap_now(arc_reclaim_strategy_t strat)
{
size_t i;
kmem_cache_t *prev_cache = NULL;
kmem_cache_t *prev_data_cache = NULL;
+ DTRACE_PROBE(arc__kmem_reap_start);
#ifdef _KERNEL
if (arc_meta_used >= arc_meta_limit) {
/*
@@ -2564,6 +2648,16 @@ arc_kmem_reap_now(arc_reclaim_strategy_t
}
kmem_cache_reap_now(buf_cache);
kmem_cache_reap_now(hdr_cache);
+
+#ifdef sun
+ /*
+ * Ask the vmem arena to reclaim unused memory from its
+ * quantum caches.
+ */
+ if (zio_arena != NULL && strat == ARC_RECLAIM_AGGR)
+ vmem_qcache_reap(zio_arena);
+#endif
+ DTRACE_PROBE(arc__kmem_reap_end);
}
static void
@@ -2581,6 +2675,7 @@ arc_reclaim_thread(void *dummy __unused)
if (arc_no_grow) {
if (last_reclaim == ARC_RECLAIM_CONS) {
+ DTRACE_PROBE(arc__reclaim_aggr_no_grow);
last_reclaim = ARC_RECLAIM_AGGR;
} else {
last_reclaim = ARC_RECLAIM_CONS;
@@ -2588,6 +2683,7 @@ arc_reclaim_thread(void *dummy __unused)
} else {
arc_no_grow = TRUE;
last_reclaim = ARC_RECLAIM_AGGR;
+ DTRACE_PROBE(arc__reclaim_aggr);
membar_producer();
}
@@ -2692,6 +2788,7 @@ arc_adapt(int bytes, arc_state_t *state)
* cache size, increment the target cache size
*/
if (arc_size > arc_c - (2ULL << SPA_MAXBLOCKSHIFT)) {
+ DTRACE_PROBE1(arc__inc_adapt, int, bytes);
atomic_add_64(&arc_c, (int64_t)bytes);
if (arc_c > arc_c_max)
arc_c = arc_c_max;
@@ -2713,20 +2810,6 @@ arc_evict_needed(arc_buf_contents_t type
if (type == ARC_BUFC_METADATA && arc_meta_used >= arc_meta_limit)
return (1);
-#ifdef sun
-#ifdef _KERNEL
- /*
- * If zio data pages are being allocated out of a separate heap segment,
- * then enforce that the size of available vmem for this area remains
- * above about 1/32nd free.
- */
- if (type == ARC_BUFC_DATA && zio_arena != NULL &&
- vmem_size(zio_arena, VMEM_FREE) <
- (vmem_size(zio_arena, VMEM_ALLOC) >> 5))
- return (1);
-#endif
-#endif /* sun */
-
if (arc_reclaim_needed())
return (1);
@@ -3885,20 +3968,16 @@ static int
arc_memory_throttle(uint64_t reserve, uint64_t txg)
{
#ifdef _KERNEL
- uint64_t available_memory =
- ptoa((uintmax_t)cnt.v_free_count + cnt.v_cache_count);
+ uint64_t available_memory = ptob(freemem);
static uint64_t page_load = 0;
static uint64_t last_txg = 0;
-#ifdef sun
-#if defined(__i386)
+#if defined(__i386) || !defined(UMA_MD_SMALL_ALLOC)
available_memory =
- MIN(available_memory, vmem_size(heap_arena, VMEM_FREE));
+ MIN(available_memory, ptob(vmem_size(heap_arena, VMEM_FREE)));
#endif
-#endif /* sun */
- if (cnt.v_free_count + cnt.v_cache_count >
- (uint64_t)physmem * arc_lotsfree_percent / 100)
+ if (freemem > (uint64_t)physmem * arc_lotsfree_percent / 100)
return (0);
if (txg > last_txg) {
@@ -3911,7 +3990,7 @@ arc_memory_throttle(uint64_t reserve, ui
* continue to let page writes occur as quickly as possible.
*/
if (curproc == pageproc) {
- if (page_load > available_memory / 4)
+ if (page_load > MAX(ptob(minfree), available_memory) / 4)
return (SET_ERROR(ERESTART));
/* Note: reserve is inflated, so we deflate */
page_load += reserve / 8;
@@ -3939,8 +4018,10 @@ arc_tempreserve_space(uint64_t reserve,
int error;
uint64_t anon_size;
- if (reserve > arc_c/4 && !arc_no_grow)
+ if (reserve > arc_c/4 && !arc_no_grow) {
arc_c = MIN(arc_c_max, reserve * 4);
+ DTRACE_PROBE1(arc__set_reserve, uint64_t, arc_c);
+ }
if (reserve > arc_c)
return (SET_ERROR(ENOMEM));
@@ -3994,6 +4075,7 @@ arc_lowmem(void *arg __unused, int howto
mutex_enter(&arc_lowmem_lock);
mutex_enter(&arc_reclaim_thr_lock);
needfree = 1;
+ DTRACE_PROBE(arc__needfree);
cv_signal(&arc_reclaim_thr_cv);
/*
Modified: stable/10/sys/vm/vm_pageout.c
==============================================================================
--- stable/10/sys/vm/vm_pageout.c Thu Oct 9 23:52:33 2014
(r272874)
+++ stable/10/sys/vm/vm_pageout.c Fri Oct 10 00:12:16 2014
(r272875)
@@ -76,6 +76,7 @@
__FBSDID("$FreeBSD$");
#include "opt_vm.h"
+#include "opt_kdtrace.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
@@ -89,6 +90,7 @@ __FBSDID("$FreeBSD$");
#include <sys/racct.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
+#include <sys/sdt.h>
#include <sys/signalvar.h>
#include <sys/smp.h>
#include <sys/vnode.h>
@@ -115,10 +117,14 @@ __FBSDID("$FreeBSD$");
/* the kernel process "vm_pageout"*/
static void vm_pageout(void);
+static void vm_pageout_init(void);
static int vm_pageout_clean(vm_page_t);
static void vm_pageout_scan(struct vm_domain *vmd, int pass);
static void vm_pageout_mightbe_oom(struct vm_domain *vmd, int pass);
+SYSINIT(pagedaemon_init, SI_SUB_KTHREAD_PAGE, SI_ORDER_FIRST, vm_pageout_init,
+ NULL);
+
struct proc *pageproc;
static struct kproc_desc page_kp = {
@@ -126,9 +132,13 @@ static struct kproc_desc page_kp = {
vm_pageout,
&pageproc
};
-SYSINIT(pagedaemon, SI_SUB_KTHREAD_PAGE, SI_ORDER_FIRST, kproc_start,
+SYSINIT(pagedaemon, SI_SUB_KTHREAD_PAGE, SI_ORDER_SECOND, kproc_start,
&page_kp);
+SDT_PROVIDER_DEFINE(vm);
+SDT_PROBE_DEFINE(vm, , , vm__lowmem_cache);
+SDT_PROBE_DEFINE(vm, , , vm__lowmem_scan);
+
#if !defined(NO_SWAPPING)
/* the kernel process "vm_daemon"*/
static void vm_daemon(void);
@@ -663,6 +673,7 @@ vm_pageout_grow_cache(int tries, vm_padd
* may acquire locks and/or sleep, so they can only be invoked
* when "tries" is greater than zero.
*/
+ SDT_PROBE0(vm, , , vm__lowmem_cache);
EVENTHANDLER_INVOKE(vm_lowmem, 0);
/*
@@ -925,6 +936,7 @@ vm_pageout_scan(struct vm_domain *vmd, i
/*
* Decrease registered cache sizes.
*/
+ SDT_PROBE0(vm, , , vm__lowmem_scan);
EVENTHANDLER_INVOKE(vm_lowmem, 0);
/*
* We do this explicitly after the caches have been
@@ -1650,15 +1662,11 @@ vm_pageout_worker(void *arg)
}
/*
- * vm_pageout is the high level pageout daemon.
+ * vm_pageout_init initialises basic pageout daemon settings.
*/
static void
-vm_pageout(void)
+vm_pageout_init(void)
{
-#if MAXMEMDOM > 1
- int error, i;
-#endif
-
/*
* Initialize some paging parameters.
*/
@@ -1704,6 +1712,17 @@ vm_pageout(void)
/* XXX does not really belong here */
if (vm_page_max_wired == 0)
vm_page_max_wired = cnt.v_free_count / 3;
+}
+
+/*
+ * vm_pageout is the high level pageout daemon.
+ */
+static void
+vm_pageout(void)
+{
+#if MAXMEMDOM > 1
+ int error, i;
+#endif
swap_pager_swap_init();
#if MAXMEMDOM > 1
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