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[Qemu-devel] [PATCH 18/18] block: make accounting thread-safe
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 18/18] block: make accounting thread-safe |
Date: |
Thu, 25 May 2017 18:32:25 +0200 |
I'm not trying too hard yet. Later, with multiqueue support,
this may cause mutex contention or cacheline bouncing.
Reviewed-by: Alberto Garcia <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
block/accounting.c | 16 ++++++++++++++++
include/block/accounting.h | 8 ++++++--
2 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/block/accounting.c b/block/accounting.c
index a279e0b..72bcb0d 100644
--- a/block/accounting.c
+++ b/block/accounting.c
@@ -35,6 +35,7 @@ static const int qtest_latency_ns = NANOSECONDS_PER_SECOND /
1000;
void block_acct_init(BlockAcctStats *stats, bool account_invalid,
bool account_failed)
{
+ qemu_mutex_init(&stats->lock);
stats->account_invalid = account_invalid;
stats->account_failed = account_failed;
@@ -49,6 +50,7 @@ void block_acct_cleanup(BlockAcctStats *stats)
QSLIST_FOREACH_SAFE(s, &stats->intervals, entries, next) {
g_free(s);
}
+ qemu_mutex_destroy(&stats->lock);
}
void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length)
@@ -58,12 +60,15 @@ void block_acct_add_interval(BlockAcctStats *stats,
unsigned interval_length)
s = g_new0(BlockAcctTimedStats, 1);
s->interval_length = interval_length;
+ s->stats = stats;
+ qemu_mutex_lock(&stats->lock);
QSLIST_INSERT_HEAD(&stats->intervals, s, entries);
for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
timed_average_init(&s->latency[i], clock_type,
(uint64_t) interval_length *
NANOSECONDS_PER_SECOND);
}
+ qemu_mutex_unlock(&stats->lock);
}
BlockAcctTimedStats *block_acct_interval_next(BlockAcctStats *stats,
@@ -99,6 +104,8 @@ static void block_account_one_io(BlockAcctStats *stats,
BlockAcctCookie *cookie,
assert(cookie->type < BLOCK_MAX_IOTYPE);
+ qemu_mutex_lock(&stats->lock);
+
if (failed) {
stats->failed_ops[cookie->type]++;
} else {
@@ -114,6 +121,8 @@ static void block_account_one_io(BlockAcctStats *stats,
BlockAcctCookie *cookie,
timed_average_account(&s->latency[cookie->type], latency_ns);
}
}
+
+ qemu_mutex_unlock(&stats->lock);
}
void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
@@ -134,18 +143,23 @@ void block_acct_invalid(BlockAcctStats *stats, enum
BlockAcctType type)
* not. The reason is that invalid requests are accounted during their
* submission, therefore there's no actual I/O involved.
*/
+ qemu_mutex_lock(&stats->lock);
stats->invalid_ops[type]++;
if (stats->account_invalid) {
stats->last_access_time_ns = qemu_clock_get_ns(clock_type);
}
+ qemu_mutex_unlock(&stats->lock);
}
void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
int num_requests)
{
assert(type < BLOCK_MAX_IOTYPE);
+
+ qemu_mutex_lock(&stats->lock);
stats->merged[type] += num_requests;
+ qemu_mutex_unlock(&stats->lock);
}
int64_t block_acct_idle_time_ns(BlockAcctStats *stats)
@@ -160,7 +174,9 @@ double block_acct_queue_depth(BlockAcctTimedStats *stats,
assert(type < BLOCK_MAX_IOTYPE);
+ qemu_mutex_lock(&stats->stats->lock);
sum = timed_average_sum(&stats->latency[type], &elapsed);
+ qemu_mutex_unlock(&stats->stats->lock);
return (double) sum / elapsed;
}
diff --git a/include/block/accounting.h b/include/block/accounting.h
index 2089163..eb69091 100644
--- a/include/block/accounting.h
+++ b/include/block/accounting.h
@@ -26,8 +26,10 @@
#define BLOCK_ACCOUNTING_H
#include "qemu/timed-average.h"
+#include "qemu/thread.h"
typedef struct BlockAcctTimedStats BlockAcctTimedStats;
+typedef struct BlockAcctStats BlockAcctStats;
enum BlockAcctType {
BLOCK_ACCT_READ,
@@ -37,12 +39,14 @@ enum BlockAcctType {
};
struct BlockAcctTimedStats {
+ BlockAcctStats *stats;
TimedAverage latency[BLOCK_MAX_IOTYPE];
unsigned interval_length; /* in seconds */
QSLIST_ENTRY(BlockAcctTimedStats) entries;
};
-typedef struct BlockAcctStats {
+struct BlockAcctStats {
+ QemuMutex lock;
uint64_t nr_bytes[BLOCK_MAX_IOTYPE];
uint64_t nr_ops[BLOCK_MAX_IOTYPE];
uint64_t invalid_ops[BLOCK_MAX_IOTYPE];
@@ -53,7 +57,7 @@ typedef struct BlockAcctStats {
QSLIST_HEAD(, BlockAcctTimedStats) intervals;
bool account_invalid;
bool account_failed;
-} BlockAcctStats;
+};
typedef struct BlockAcctCookie {
int64_t bytes;
--
1.8.3.1
- [Qemu-devel] [PATCH 09/18] throttle-groups: protect throttled requests with a CoMutex, (continued)
- [Qemu-devel] [PATCH 09/18] throttle-groups: protect throttled requests with a CoMutex, Paolo Bonzini, 2017/05/25
- [Qemu-devel] [PATCH 06/18] block: access io_plugged with atomic ops, Paolo Bonzini, 2017/05/25
- [Qemu-devel] [PATCH 07/18] throttle-groups: only start one coroutine from drained_begin, Paolo Bonzini, 2017/05/25
- [Qemu-devel] [PATCH 08/18] throttle-groups: do not use qemu_co_enter_next, Paolo Bonzini, 2017/05/25
- [Qemu-devel] [PATCH 11/18] block: use Stat64 for wr_highest_offset, Paolo Bonzini, 2017/05/25
- [Qemu-devel] [PATCH 10/18] util: add stats64 module, Paolo Bonzini, 2017/05/25
- [Qemu-devel] [PATCH 12/18] block: access write_gen with atomics, Paolo Bonzini, 2017/05/25
- [Qemu-devel] [PATCH 13/18] block: protect tracked_requests and flush_queue with reqs_lock, Paolo Bonzini, 2017/05/25
- [Qemu-devel] [PATCH 15/18] migration/block: reset dirty bitmap before reading, Paolo Bonzini, 2017/05/25
- [Qemu-devel] [PATCH 17/18] block: introduce block_account_one_io, Paolo Bonzini, 2017/05/25
- [Qemu-devel] [PATCH 18/18] block: make accounting thread-safe,
Paolo Bonzini <=
- [Qemu-devel] [PATCH 16/18] block: protect modification of dirty bitmaps with a mutex, Paolo Bonzini, 2017/05/25
- [Qemu-devel] [PATCH 14/18] block: introduce dirty_bitmap_mutex, Paolo Bonzini, 2017/05/25
- Re: [Qemu-devel] [PATCH v3 00/18] Block layer thread safety, part 1, no-reply, 2017/05/25
- Re: [Qemu-devel] [PATCH v3 00/18] Block layer thread safety, part 1, Fam Zheng, 2017/05/25