From 979e9b03fc8c85d3b78a14410c64cbb16d348095 Mon Sep 17 00:00:00 2001 From: Alberto Garcia Date: Wed, 28 Oct 2015 17:33:05 +0200 Subject: block: Compute minimum, maximum and average I/O latencies This patch keeps track of the minimum, maximum and average latencies of I/O operations during a certain interval of time. The values are exposed in the BlockDeviceTimedStats structure. An option to define the intervals to collect these statistics will be added in a separate patch. Signed-off-by: Alberto Garcia Message-id: c7382dc89622c64f918d09f32815827772628f8e.1446044837.git.berto@igalia.com Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/accounting.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'block/accounting.c') diff --git a/block/accounting.c b/block/accounting.c index 923aeaf5be..61de8ce9bc 100644 --- a/block/accounting.c +++ b/block/accounting.c @@ -35,6 +35,39 @@ void block_acct_init(BlockAcctStats *stats, bool account_invalid, stats->account_failed = account_failed; } +void block_acct_cleanup(BlockAcctStats *stats) +{ + BlockAcctTimedStats *s, *next; + QSLIST_FOREACH_SAFE(s, &stats->intervals, entries, next) { + g_free(s); + } +} + +void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length) +{ + BlockAcctTimedStats *s; + unsigned i; + + s = g_new0(BlockAcctTimedStats, 1); + s->interval_length = interval_length; + 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); + } +} + +BlockAcctTimedStats *block_acct_interval_next(BlockAcctStats *stats, + BlockAcctTimedStats *s) +{ + if (s == NULL) { + return QSLIST_FIRST(&stats->intervals); + } else { + return QSLIST_NEXT(s, entries); + } +} + void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie, int64_t bytes, enum BlockAcctType type) { @@ -47,6 +80,7 @@ void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie, void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie) { + BlockAcctTimedStats *s; int64_t time_ns = qemu_clock_get_ns(clock_type); int64_t latency_ns = time_ns - cookie->start_time_ns; @@ -56,6 +90,10 @@ void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie) stats->nr_ops[cookie->type]++; stats->total_time_ns[cookie->type] += latency_ns; stats->last_access_time_ns = time_ns; + + QSLIST_FOREACH(s, &stats->intervals, entries) { + timed_average_account(&s->latency[cookie->type], latency_ns); + } } void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie) @@ -65,11 +103,16 @@ void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie) stats->failed_ops[cookie->type]++; if (stats->account_failed) { + BlockAcctTimedStats *s; int64_t time_ns = qemu_clock_get_ns(clock_type); int64_t latency_ns = time_ns - cookie->start_time_ns; stats->total_time_ns[cookie->type] += latency_ns; stats->last_access_time_ns = time_ns; + + QSLIST_FOREACH(s, &stats->intervals, entries) { + timed_average_account(&s->latency[cookie->type], latency_ns); + } } } -- cgit v1.2.1