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5817 change type of arcs_size from uint64_t to refcount_t
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Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <paul.dagnelie@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Garrett D'Amore <garrett@damore.org>
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@prakashsurya @ahrens
prakashsurya authored and ahrens committed Apr 11, 2015
1 parent 34e8ace commit 2fd872a
Showing 1 changed file with 108 additions and 25 deletions.
133 changes: 108 additions & 25 deletions usr/src/uts/common/fs/zfs/arc.c
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Expand Up @@ -21,7 +21,7 @@
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, Joyent, Inc. All rights reserved.
* Copyright (c) 2011, 2014 by Delphix. All rights reserved.
* Copyright (c) 2011, 2015 by Delphix. All rights reserved.
* Copyright (c) 2014 by Saso Kiselkov. All rights reserved.
* Copyright 2014 Nexenta Systems, Inc. All rights reserved.
*/
Expand Down Expand Up @@ -273,7 +273,7 @@ typedef struct arc_state {
* total amount of data in this state; this includes: evictable,
* non-evictable, ARC_BUFC_DATA, and ARC_BUFC_METADATA.
*/
uint64_t arcs_size;
refcount_t arcs_size;
} arc_state_t;

/* The 6 states: */
Expand Down Expand Up @@ -1649,12 +1649,73 @@ arc_change_state(arc_state_t *new_state, arc_buf_hdr_t *hdr,
buf_hash_remove(hdr);

/* adjust state sizes (ignore arc_l2c_only) */
if (to_delta && new_state != arc_l2c_only)
atomic_add_64(&new_state->arcs_size, to_delta);

if (to_delta && new_state != arc_l2c_only) {
ASSERT(HDR_HAS_L1HDR(hdr));
if (GHOST_STATE(new_state)) {
ASSERT0(datacnt);

/*
* We moving a header to a ghost state, we first
* remove all arc buffers. Thus, we'll have a
* datacnt of zero, and no arc buffer to use for
* the reference. As a result, we use the arc
* header pointer for the reference.
*/
(void) refcount_add_many(&new_state->arcs_size,
hdr->b_size, hdr);
} else {
ASSERT3U(datacnt, !=, 0);

/*
* Each individual buffer holds a unique reference,
* thus we must remove each of these references one
* at a time.
*/
for (arc_buf_t *buf = hdr->b_l1hdr.b_buf; buf != NULL;
buf = buf->b_next) {
(void) refcount_add_many(&new_state->arcs_size,
hdr->b_size, buf);
}
}
}

if (from_delta && old_state != arc_l2c_only) {
ASSERT3U(old_state->arcs_size, >=, from_delta);
atomic_add_64(&old_state->arcs_size, -from_delta);
ASSERT(HDR_HAS_L1HDR(hdr));
if (GHOST_STATE(old_state)) {
/*
* When moving a header off of a ghost state,
* there's the possibility for datacnt to be
* non-zero. This is because we first add the
* arc buffer to the header prior to changing
* the header's state. Since we used the header
* for the reference when putting the header on
* the ghost state, we must balance that and use
* the header when removing off the ghost state
* (even though datacnt is non zero).
*/

IMPLY(datacnt == 0, new_state == arc_anon ||
new_state == arc_l2c_only);

(void) refcount_remove_many(&old_state->arcs_size,
hdr->b_size, hdr);
} else {
ASSERT3P(datacnt, !=, 0);

/*
* Each individual buffer holds a unique reference,
* thus we must remove each of these references one
* at a time.
*/
for (arc_buf_t *buf = hdr->b_l1hdr.b_buf; buf != NULL;
buf = buf->b_next) {
(void) refcount_remove_many(
&old_state->arcs_size, hdr->b_size, buf);
}
}
}

if (HDR_HAS_L1HDR(hdr))
hdr->b_l1hdr.b_state = new_state;

Expand Down Expand Up @@ -2011,8 +2072,8 @@ arc_buf_destroy(arc_buf_t *buf, boolean_t remove)
ASSERT3U(*cnt, >=, size);
atomic_add_64(cnt, -size);
}
ASSERT3U(state->arcs_size, >=, size);
atomic_add_64(&state->arcs_size, -size);

(void) refcount_remove_many(&state->arcs_size, size, buf);
buf->b_data = NULL;

/*
Expand Down Expand Up @@ -2684,7 +2745,8 @@ arc_adjust_meta(void)
* evict some from the MRU here, and some from the MFU below.
*/
target = MIN((int64_t)(arc_meta_used - arc_meta_limit),
(int64_t)(arc_anon->arcs_size + arc_mru->arcs_size - arc_p));
(int64_t)(refcount_count(&arc_anon->arcs_size) +
refcount_count(&arc_mru->arcs_size) - arc_p));

total_evicted += arc_adjust_impl(arc_mru, 0, target, ARC_BUFC_METADATA);

Expand All @@ -2694,7 +2756,7 @@ arc_adjust_meta(void)
* space alloted to the MFU (which is defined as arc_c - arc_p).
*/
target = MIN((int64_t)(arc_meta_used - arc_meta_limit),
(int64_t)(arc_mfu->arcs_size - (arc_c - arc_p)));
(int64_t)(refcount_count(&arc_mfu->arcs_size) - (arc_c - arc_p)));

total_evicted += arc_adjust_impl(arc_mfu, 0, target, ARC_BUFC_METADATA);

Expand Down Expand Up @@ -2803,8 +2865,8 @@ arc_adjust(void)
* arc_p here, and then evict more from the MFU below.
*/
target = MIN((int64_t)(arc_size - arc_c),
(int64_t)(arc_anon->arcs_size + arc_mru->arcs_size + arc_meta_used -
arc_p));
(int64_t)(refcount_count(&arc_anon->arcs_size) +
refcount_count(&arc_mru->arcs_size) + arc_meta_used - arc_p));

/*
* If we're below arc_meta_min, always prefer to evict data.
Expand Down Expand Up @@ -2888,7 +2950,8 @@ arc_adjust(void)
* cache. The following logic enforces these limits on the ghost
* caches, and evicts from them as needed.
*/
target = arc_mru->arcs_size + arc_mru_ghost->arcs_size - arc_c;
target = refcount_count(&arc_mru->arcs_size) +
refcount_count(&arc_mru_ghost->arcs_size) - arc_c;

bytes = arc_adjust_impl(arc_mru_ghost, 0, target, ARC_BUFC_DATA);
total_evicted += bytes;
Expand All @@ -2906,7 +2969,8 @@ arc_adjust(void)
* mru + mfu + mru ghost + mfu ghost <= 2 * arc_c
* mru ghost + mfu ghost <= arc_c
*/
target = arc_mru_ghost->arcs_size + arc_mfu_ghost->arcs_size - arc_c;
target = refcount_count(&arc_mru_ghost->arcs_size) +
refcount_count(&arc_mfu_ghost->arcs_size) - arc_c;

bytes = arc_adjust_impl(arc_mfu_ghost, 0, target, ARC_BUFC_DATA);
total_evicted += bytes;
Expand Down Expand Up @@ -3351,6 +3415,8 @@ arc_adapt(int bytes, arc_state_t *state)
{
int mult;
uint64_t arc_p_min = (arc_c >> arc_p_min_shift);
int64_t mrug_size = refcount_count(&arc_mru_ghost->arcs_size);
int64_t mfug_size = refcount_count(&arc_mfu_ghost->arcs_size);

if (state == arc_l2c_only)
return;
Expand All @@ -3365,16 +3431,14 @@ arc_adapt(int bytes, arc_state_t *state)
* target size of the MRU list.
*/
if (state == arc_mru_ghost) {
mult = ((arc_mru_ghost->arcs_size >= arc_mfu_ghost->arcs_size) ?
1 : (arc_mfu_ghost->arcs_size/arc_mru_ghost->arcs_size));
mult = (mrug_size >= mfug_size) ? 1 : (mfug_size / mrug_size);
mult = MIN(mult, 10); /* avoid wild arc_p adjustment */

arc_p = MIN(arc_c - arc_p_min, arc_p + bytes * mult);
} else if (state == arc_mfu_ghost) {
uint64_t delta;

mult = ((arc_mfu_ghost->arcs_size >= arc_mru_ghost->arcs_size) ?
1 : (arc_mru_ghost->arcs_size/arc_mfu_ghost->arcs_size));
mult = (mfug_size >= mrug_size) ? 1 : (mrug_size / mfug_size);
mult = MIN(mult, 10);

delta = MIN(bytes * mult, arc_p);
Expand Down Expand Up @@ -3490,8 +3554,9 @@ arc_get_data_buf(arc_buf_t *buf)
*/
if (!GHOST_STATE(buf->b_hdr->b_l1hdr.b_state)) {
arc_buf_hdr_t *hdr = buf->b_hdr;
arc_state_t *state = hdr->b_l1hdr.b_state;

atomic_add_64(&hdr->b_l1hdr.b_state->arcs_size, size);
(void) refcount_add_many(&state->arcs_size, size, buf);

/*
* If this is reached via arc_read, the link is
Expand All @@ -3512,7 +3577,8 @@ arc_get_data_buf(arc_buf_t *buf)
* data, and we have outgrown arc_p, update arc_p
*/
if (arc_size < arc_c && hdr->b_l1hdr.b_state == arc_anon &&
arc_anon->arcs_size + arc_mru->arcs_size > arc_p)
(refcount_count(&arc_anon->arcs_size) +
refcount_count(&arc_mru->arcs_size) > arc_p))
arc_p = MIN(arc_c, arc_p + size);
}
}
Expand Down Expand Up @@ -4360,8 +4426,10 @@ arc_release(arc_buf_t *buf, void *tag)
buf->b_next = NULL;

ASSERT3P(state, !=, arc_l2c_only);
ASSERT3U(state->arcs_size, >=, hdr->b_size);
atomic_add_64(&state->arcs_size, -hdr->b_size);

(void) refcount_remove_many(
&state->arcs_size, hdr->b_size, buf);

if (refcount_is_zero(&hdr->b_l1hdr.b_refcnt)) {
ASSERT3P(state, !=, arc_l2c_only);
uint64_t *size = &state->arcs_lsize[type];
Expand Down Expand Up @@ -4402,7 +4470,7 @@ arc_release(arc_buf_t *buf, void *tag)
(void) refcount_add(&nhdr->b_l1hdr.b_refcnt, tag);
buf->b_hdr = nhdr;
mutex_exit(&buf->b_evict_lock);
atomic_add_64(&arc_anon->arcs_size, blksz);
(void) refcount_add_many(&arc_anon->arcs_size, blksz, buf);
} else {
mutex_exit(&buf->b_evict_lock);
ASSERT(refcount_count(&hdr->b_l1hdr.b_refcnt) == 1);
Expand Down Expand Up @@ -4667,7 +4735,8 @@ arc_tempreserve_space(uint64_t reserve, uint64_t txg)
* network delays from blocking transactions that are ready to be
* assigned to a txg.
*/
anon_size = MAX((int64_t)(arc_anon->arcs_size - arc_loaned_bytes), 0);
anon_size = MAX((int64_t)(refcount_count(&arc_anon->arcs_size) -
arc_loaned_bytes), 0);

/*
* Writes will, almost always, require additional memory allocations
Expand Down Expand Up @@ -4704,7 +4773,7 @@ static void
arc_kstat_update_state(arc_state_t *state, kstat_named_t *size,
kstat_named_t *evict_data, kstat_named_t *evict_metadata)
{
size->value.ui64 = state->arcs_size;
size->value.ui64 = refcount_count(&state->arcs_size);
evict_data->value.ui64 = state->arcs_lsize[ARC_BUFC_DATA];
evict_metadata->value.ui64 = state->arcs_lsize[ARC_BUFC_METADATA];
}
Expand Down Expand Up @@ -4921,6 +4990,13 @@ arc_init(void)
offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node),
zfs_arc_num_sublists_per_state, arc_state_multilist_index_func);

refcount_create(&arc_anon->arcs_size);
refcount_create(&arc_mru->arcs_size);
refcount_create(&arc_mru_ghost->arcs_size);
refcount_create(&arc_mfu->arcs_size);
refcount_create(&arc_mfu_ghost->arcs_size);
refcount_create(&arc_l2c_only->arcs_size);

buf_init();

arc_reclaim_thread_exit = FALSE;
Expand Down Expand Up @@ -5006,6 +5082,13 @@ arc_fini(void)
mutex_destroy(&arc_user_evicts_lock);
cv_destroy(&arc_user_evicts_cv);

refcount_destroy(&arc_anon->arcs_size);
refcount_destroy(&arc_mru->arcs_size);
refcount_destroy(&arc_mru_ghost->arcs_size);
refcount_destroy(&arc_mfu->arcs_size);
refcount_destroy(&arc_mfu_ghost->arcs_size);
refcount_destroy(&arc_l2c_only->arcs_size);

multilist_destroy(&arc_mru->arcs_list[ARC_BUFC_METADATA]);
multilist_destroy(&arc_mru_ghost->arcs_list[ARC_BUFC_METADATA]);
multilist_destroy(&arc_mfu->arcs_list[ARC_BUFC_METADATA]);
Expand Down

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