Author: kib
Date: Fri Jun 17 17:34:28 2016
New Revision: 301997
URL: https://svnweb.freebsd.org/changeset/base/301997
Log:
Use vnlru_free(9) to implement dnlc_reduce_cache().
This apparently puts ARC back under the limits after the vnode pressure
rework in r291244, in particular due to the kmem exhaustion.
Based on patch by: mckusick
Reviewed by: avg, mckusick
Tested by: allanjude, madpilot
Sponsored by: The FreeBSD Foundation
Approved by: re (gjb)
Modified:
head/sys/cddl/compat/opensolaris/sys/dnlc.h
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
Modified: head/sys/cddl/compat/opensolaris/sys/dnlc.h
==============================================================================
--- head/sys/cddl/compat/opensolaris/sys/dnlc.h Fri Jun 17 17:33:25 2016
(r301996)
+++ head/sys/cddl/compat/opensolaris/sys/dnlc.h Fri Jun 17 17:34:28 2016
(r301997)
@@ -35,6 +35,6 @@
#define dnlc_update(dvp, name, vp) do { } while (0)
#define dnlc_remove(dvp, name) do { } while (0)
#define dnlc_purge_vfsp(vfsp, count) (0)
-#define dnlc_reduce_cache(percent) do { } while (0)
+void dnlc_reduce_cache(void *arg);
#endif /* !_OPENSOLARIS_SYS_DNLC_H_ */
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Fri Jun 17
17:33:25 2016 (r301996)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Fri Jun 17
17:34:28 2016 (r301997)
@@ -159,6 +159,10 @@ static kmutex_t arc_user_evicts_lock;
static kcondvar_t arc_user_evicts_cv;
static boolean_t arc_user_evicts_thread_exit;
+static kmutex_t arc_dnlc_evicts_lock;
+static kcondvar_t arc_dnlc_evicts_cv;
+static boolean_t arc_dnlc_evicts_thread_exit;
+
uint_t arc_reduce_dnlc_percent = 3;
/*
@@ -3749,6 +3753,57 @@ arc_user_evicts_thread(void *dummy __unu
thread_exit();
}
+static u_int arc_dnlc_evicts_arg;
+extern struct vfsops zfs_vfsops;
+
+static void
+arc_dnlc_evicts_thread(void *dummy __unused)
+{
+ callb_cpr_t cpr;
+ u_int percent;
+
+ CALLB_CPR_INIT(&cpr, &arc_dnlc_evicts_lock, callb_generic_cpr, FTAG);
+
+ mutex_enter(&arc_dnlc_evicts_lock);
+ while (!arc_dnlc_evicts_thread_exit) {
+ CALLB_CPR_SAFE_BEGIN(&cpr);
+ (void) cv_wait(&arc_dnlc_evicts_cv, &arc_dnlc_evicts_lock);
+ CALLB_CPR_SAFE_END(&cpr, &arc_dnlc_evicts_lock);
+ if (arc_dnlc_evicts_arg != 0) {
+ percent = arc_dnlc_evicts_arg;
+ mutex_exit(&arc_dnlc_evicts_lock);
+#ifdef _KERNEL
+ vnlru_free(desiredvnodes * percent / 100, &zfs_vfsops);
+#endif
+ mutex_enter(&arc_dnlc_evicts_lock);
+ /*
+ * Clear our token only after vnlru_free()
+ * pass is done, to avoid false queueing of
+ * the requests.
+ */
+ arc_dnlc_evicts_arg = 0;
+ }
+ }
+ arc_dnlc_evicts_thread_exit = FALSE;
+ cv_broadcast(&arc_dnlc_evicts_cv);
+ CALLB_CPR_EXIT(&cpr);
+ thread_exit();
+}
+
+void
+dnlc_reduce_cache(void *arg)
+{
+ u_int percent;
+
+ percent = (u_int)arg;
+ mutex_enter(&arc_dnlc_evicts_lock);
+ if (arc_dnlc_evicts_arg == 0) {
+ arc_dnlc_evicts_arg = percent;
+ cv_broadcast(&arc_dnlc_evicts_cv);
+ }
+ mutex_exit(&arc_dnlc_evicts_lock);
+}
+
/*
* Adapt arc info given the number of bytes we are trying to add and
* the state that we are comming from. This function is only called
@@ -5311,6 +5366,9 @@ arc_init(void)
mutex_init(&arc_user_evicts_lock, NULL, MUTEX_DEFAULT, NULL);
cv_init(&arc_user_evicts_cv, NULL, CV_DEFAULT, NULL);
+ mutex_init(&arc_dnlc_evicts_lock, NULL, MUTEX_DEFAULT, NULL);
+ cv_init(&arc_dnlc_evicts_cv, NULL, CV_DEFAULT, NULL);
+
/* Convert seconds to clock ticks */
arc_min_prefetch_lifespan = 1 * hz;
@@ -5463,6 +5521,7 @@ arc_init(void)
arc_reclaim_thread_exit = FALSE;
arc_user_evicts_thread_exit = FALSE;
+ arc_dnlc_evicts_thread_exit = FALSE;
arc_eviction_list = NULL;
bzero(&arc_eviction_hdr, sizeof (arc_buf_hdr_t));
@@ -5486,6 +5545,9 @@ arc_init(void)
(void) thread_create(NULL, 0, arc_user_evicts_thread, NULL, 0, &p0,
TS_RUN, minclsyspri);
+ (void) thread_create(NULL, 0, arc_dnlc_evicts_thread, NULL, 0, &p0,
+ TS_RUN, minclsyspri);
+
arc_dead = FALSE;
arc_warm = B_FALSE;
@@ -5568,6 +5630,18 @@ arc_fini(void)
}
mutex_exit(&arc_user_evicts_lock);
+ mutex_enter(&arc_dnlc_evicts_lock);
+ arc_dnlc_evicts_thread_exit = TRUE;
+ /*
+ * The user evicts thread will set arc_user_evicts_thread_exit
+ * to FALSE when it is finished exiting; we're waiting for that.
+ */
+ while (arc_dnlc_evicts_thread_exit) {
+ cv_signal(&arc_dnlc_evicts_cv);
+ cv_wait(&arc_dnlc_evicts_cv, &arc_dnlc_evicts_lock);
+ }
+ mutex_exit(&arc_dnlc_evicts_lock);
+
/* Use TRUE to ensure *all* buffers are evicted */
arc_flush(NULL, TRUE);
@@ -5585,6 +5659,9 @@ arc_fini(void)
mutex_destroy(&arc_user_evicts_lock);
cv_destroy(&arc_user_evicts_cv);
+ mutex_destroy(&arc_dnlc_evicts_lock);
+ cv_destroy(&arc_dnlc_evicts_cv);
+
refcount_destroy(&arc_anon->arcs_size);
refcount_destroy(&arc_mru->arcs_size);
refcount_destroy(&arc_mru_ghost->arcs_size);
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c Fri Jun
17 17:33:25 2016 (r301996)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c Fri Jun
17 17:34:28 2016 (r301997)
@@ -101,7 +101,7 @@ static int zfs_fhtovp(vfs_t *vfsp, fid_t
static void zfs_objset_close(zfsvfs_t *zfsvfs);
static void zfs_freevfs(vfs_t *vfsp);
-static struct vfsops zfs_vfsops = {
+struct vfsops zfs_vfsops = {
.vfs_mount = zfs_mount,
.vfs_unmount = zfs_umount,
.vfs_root = zfs_root,
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