freebsd-nq/include/sys/trace_multilist.h
Prakash Surya ca0bf58d65 Illumos 5497 - lock contention on arcs_mtx
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Dan McDonald <danmcd@omniti.com>

Porting notes and other significant code changes:

The illumos 5368 patch (ARC should cache more metadata), which
was never picked up by ZoL, is mostly reverted by this patch.

Since ZoL relies on the kernel asynchronously calling the shrinker to
actually reap memory, the shrinker wakes up arc_reclaim_waiters_cv every
time it runs.

The arc_adapt_thread() function no longer calls arc_do_user_evicts()
since the newly-added arc_user_evicts_thread() calls it periodically.

Notable conflicting ZoL commits which conflicted with this patch or
whose effects are either duplicated or un-done by this patch:

    302f753 - Integrate ARC more tightly with Linux
    39e055c - Adjust arc_p based on "bytes" in arc_shrink
    f521ce1 - Allow "arc_p" to drop to zero or grow to "arc_c"
    77765b5 - Remove "arc_meta_used" from arc_adjust calculation
    94520ca - Prune metadata from ghost lists in arc_adjust_meta

Trace support for multilist_insert() and multilist_remove() has been
added and produces the following output:

    fio-12498 [077] .... 112936.448324: zfs_multilist__insert: ml { offset 240 numsublists 80 sublistidx 63 }
    fio-12498 [077] .... 112936.448347: zfs_multilist__remove: ml { offset 240 numsublists 80 sublistidx 29 }

The following arcstats have been removed:

    recycle_miss - Used by arcstat.py and arc_summary.py, both of which
    have been updated appropriately.

    l2_writes_hdr_miss

The following arcstats have been added:

    evict_not_enough - Number of times arc_evict_state() was unable to
    evict enough buffers to reach its target amount.

    evict_l2_skip - Number of times arc_evict_hdr() skipped eviction
    because it was being written to the l2arc.

    l2_writes_lock_retry - Replaces l2_writes_hdr_miss.  Number of times
    l2arc_write_done() failed to acquire hash_lock (and re-tries).

    arc_meta_min - Shows the value of the zfs_arc_meta_min module
    parameter (see below).

The "index" column of the "dbuf" kstat has been removed since it doesn't
have a direct analog in the new multilist scheme.  Additional multilist-
related stats could be added in the future but would likely require
extensions to the mulilist API.

The following module parameters have been added:

    zfs_arc_evict_batch_limit - Number of ARC headers to free per sub-list
    before moving on to the next sub-list.

    zfs_arc_meta_min - Enforce a floor on the amount of metadata in
    the ARC.

    zfs_arc_num_sublists_per_state - Number of multilist sub-lists per
    ARC state.

    zfs_arc_overflow_shift - Controls amount by which the ARC must exceed
    the target size to be considered "overflowing".

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov
2015-06-11 10:27:25 -07:00

77 lines
2.3 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
#if defined(_KERNEL) && defined(HAVE_DECLARE_EVENT_CLASS)
#undef TRACE_SYSTEM
#define TRACE_SYSTEM zfs
#if !defined(_TRACE_MULTILIST_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_MULTILIST_H
#include <linux/tracepoint.h>
#include <sys/types.h>
/*
* Generic support for three argument tracepoints of the form:
*
* DTRACE_PROBE3(...,
* multilist_t *, ...,
* unsigned int, ...,
* void *, ...);
*/
DECLARE_EVENT_CLASS(zfs_multilist_insert_remove_class,
TP_PROTO(multilist_t *ml, unsigned sublist_idx, void *obj),
TP_ARGS(ml, sublist_idx, obj),
TP_STRUCT__entry(
__field(size_t, ml_offset)
__field(uint64_t, ml_num_sublists)
__field(unsigned int, sublist_idx)
),
TP_fast_assign(
__entry->ml_offset = ml->ml_offset;
__entry->ml_num_sublists = ml->ml_num_sublists;
__entry->sublist_idx = sublist_idx;
),
TP_printk("ml { offset %ld numsublists %llu sublistidx %u } ",
__entry->ml_offset, __entry->ml_num_sublists, __entry->sublist_idx)
);
#define DEFINE_MULTILIST_INSERT_REMOVE_EVENT(name) \
DEFINE_EVENT(zfs_multilist_insert_remove_class, name, \
TP_PROTO(multilist_t *ml, unsigned int sublist_idx, void *obj), \
TP_ARGS(ml, sublist_idx, obj))
DEFINE_MULTILIST_INSERT_REMOVE_EVENT(zfs_multilist__insert);
DEFINE_MULTILIST_INSERT_REMOVE_EVENT(zfs_multilist__remove);
#endif /* _TRACE_MULTILIST_H */
#undef TRACE_INCLUDE_PATH
#undef TRACE_INCLUDE_FILE
#define TRACE_INCLUDE_PATH sys
#define TRACE_INCLUDE_FILE trace_multilist
#include <trace/define_trace.h>
#endif /* _KERNEL && HAVE_DECLARE_EVENT_CLASS */