From 3ccab25205cc8836ceb79bbd164208021468233a Mon Sep 17 00:00:00 2001 From: Ned Bass Date: Thu, 27 Feb 2014 16:32:36 -0800 Subject: [PATCH] replace nreserved with ndirty in txgs kstat The nreserved column in the txgs kstat file always contains 0 following the write throttle restructuring of commit e8b96c6007bf97cdf34869c1ffbd0ce753873a3d. Prior to that commit, the nreserved column showed the number of bytes temporarily reserved in the pool by a transaction group at sync time. The new write throttle did away with temporary reservations and uses the amount of dirty data instead. To approximate the old output of the txgs kstat, the number of dirty bytes per-txg was passed in as the nreserved value to spa_txg_history_set_io(). This approach did not work as intended, because the per-txg dirty value is decremented as data is written out to disk, so it is zero by the time we call spa_txg_history_set_io(). To fix this, save the number of dirty bytes before calling spa_sync(), and pass this value in to spa_txg_history_set_io(). Also, since the name "nreserved" is now a misnomer, the column heading is now labeled "ndirty". Signed-off-by: Ned Bass Signed-off-by: Brian Behlendorf Issue #1696 --- include/sys/spa.h | 2 +- module/zfs/spa_stats.c | 10 +++++----- module/zfs/txg.c | 4 +++- 3 files changed, 9 insertions(+), 7 deletions(-) diff --git a/include/sys/spa.h b/include/sys/spa.h index e7cbff806d..d5a91c2d31 100644 --- a/include/sys/spa.h +++ b/include/sys/spa.h @@ -570,7 +570,7 @@ extern void spa_txg_history_add(spa_t *spa, uint64_t txg, hrtime_t birth_time); extern int spa_txg_history_set(spa_t *spa, uint64_t txg, txg_state_t completed_state, hrtime_t completed_time); extern int spa_txg_history_set_io(spa_t *spa, uint64_t txg, uint64_t nread, - uint64_t nwritten, uint64_t reads, uint64_t writes, uint64_t nreserved); + uint64_t nwritten, uint64_t reads, uint64_t writes, uint64_t ndirty); extern void spa_tx_assign_add_nsecs(spa_t *spa, uint64_t nsecs); /* Pool configuration locks */ diff --git a/module/zfs/spa_stats.c b/module/zfs/spa_stats.c index a35f5df656..dbc761e115 100644 --- a/module/zfs/spa_stats.c +++ b/module/zfs/spa_stats.c @@ -248,7 +248,7 @@ typedef struct spa_txg_history { uint64_t nwritten; /* number of bytes written */ uint64_t reads; /* number of read operations */ uint64_t writes; /* number of write operations */ - uint64_t nreserved; /* number of bytes reserved */ + uint64_t ndirty; /* number of dirty bytes */ hrtime_t times[TXG_STATE_COMMITTED]; /* completion times */ list_node_t sth_link; } spa_txg_history_t; @@ -258,7 +258,7 @@ spa_txg_history_headers(char *buf, size_t size) { size = snprintf(buf, size - 1, "%-8s %-16s %-5s %-12s %-12s %-12s " "%-8s %-8s %-12s %-12s %-12s %-12s\n", "txg", "birth", "state", - "nreserved", "nread", "nwritten", "reads", "writes", + "ndirty", "nread", "nwritten", "reads", "writes", "otime", "qtime", "wtime", "stime"); buf[size] = '\0'; @@ -301,7 +301,7 @@ spa_txg_history_data(char *buf, size_t size, void *data) size = snprintf(buf, size - 1, "%-8llu %-16llu %-5c %-12llu " "%-12llu %-12llu %-8llu %-8llu %-12llu %-12llu %-12llu %-12llu\n", (longlong_t)sth->txg, sth->times[TXG_STATE_BIRTH], state, - (u_longlong_t)sth->nreserved, + (u_longlong_t)sth->ndirty, (u_longlong_t)sth->nread, (u_longlong_t)sth->nwritten, (u_longlong_t)sth->reads, (u_longlong_t)sth->writes, (u_longlong_t)open, (u_longlong_t)quiesce, (u_longlong_t)wait, @@ -482,7 +482,7 @@ spa_txg_history_set(spa_t *spa, uint64_t txg, txg_state_t completed_state, */ int spa_txg_history_set_io(spa_t *spa, uint64_t txg, uint64_t nread, - uint64_t nwritten, uint64_t reads, uint64_t writes, uint64_t nreserved) + uint64_t nwritten, uint64_t reads, uint64_t writes, uint64_t ndirty) { spa_stats_history_t *ssh = &spa->spa_stats.txg_history; spa_txg_history_t *sth; @@ -499,7 +499,7 @@ spa_txg_history_set_io(spa_t *spa, uint64_t txg, uint64_t nread, sth->nwritten = nwritten; sth->reads = reads; sth->writes = writes; - sth->nreserved = nreserved; + sth->ndirty = ndirty; error = 0; break; } diff --git a/module/zfs/txg.c b/module/zfs/txg.c index 9e9db9989f..524fe8e843 100644 --- a/module/zfs/txg.c +++ b/module/zfs/txg.c @@ -500,6 +500,7 @@ txg_sync_thread(dsl_pool_t *dp) for (;;) { uint64_t timer, timeout; uint64_t txg; + uint64_t ndirty; timeout = zfs_txg_timeout * hz; @@ -557,6 +558,7 @@ txg_sync_thread(dsl_pool_t *dp) spa_txg_history_set(spa, txg, TXG_STATE_WAIT_FOR_SYNC, gethrtime()); + ndirty = dp->dp_dirty_pertxg[txg & TXG_MASK]; start = ddi_get_lbolt(); spa_sync(spa, txg); @@ -579,7 +581,7 @@ txg_sync_thread(dsl_pool_t *dp) vs2->vs_bytes[ZIO_TYPE_WRITE]-vs1->vs_bytes[ZIO_TYPE_WRITE], vs2->vs_ops[ZIO_TYPE_READ]-vs1->vs_ops[ZIO_TYPE_READ], vs2->vs_ops[ZIO_TYPE_WRITE]-vs1->vs_ops[ZIO_TYPE_WRITE], - dp->dp_dirty_pertxg[txg & TXG_MASK]); + ndirty); spa_txg_history_set(spa, txg, TXG_STATE_SYNCED, gethrtime()); } }