From 3f54b74af40b22333965b536b8a9aad1dba482e9 Mon Sep 17 00:00:00 2001 From: delphij Date: Mon, 6 Oct 2014 07:03:17 +0000 Subject: [PATCH] MFV r272585: Split the godfather zio into CPU number's to reduce lock contention. Illumos issue: 5176 lock contention on godfather zio MFC after: 2 weeks --- cddl/contrib/opensolaris/cmd/zdb/zdb.c | 10 +++++---- .../opensolaris/uts/common/fs/zfs/spa.c | 22 ++++++++++++++----- .../uts/common/fs/zfs/sys/spa_impl.h | 3 ++- .../opensolaris/uts/common/fs/zfs/zio.c | 2 +- 4 files changed, 26 insertions(+), 11 deletions(-) diff --git a/cddl/contrib/opensolaris/cmd/zdb/zdb.c b/cddl/contrib/opensolaris/cmd/zdb/zdb.c index 04970fc70bd4..f7cacaa997f3 100644 --- a/cddl/contrib/opensolaris/cmd/zdb/zdb.c +++ b/cddl/contrib/opensolaris/cmd/zdb/zdb.c @@ -2594,10 +2594,12 @@ dump_block_stats(spa_t *spa) * all async I/Os to complete. */ if (dump_opt['c']) { - (void) zio_wait(spa->spa_async_zio_root); - spa->spa_async_zio_root = zio_root(spa, NULL, NULL, - ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | - ZIO_FLAG_GODFATHER); + for (int i = 0; i < max_ncpus; i++) { + (void) zio_wait(spa->spa_async_zio_root[i]); + spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL, + ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | + ZIO_FLAG_GODFATHER); + } } if (zcb.zcb_haderrors) { diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c index 0100206645f9..2cdfeb0f2442 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c @@ -1277,7 +1277,9 @@ spa_unload(spa_t *spa) * Wait for any outstanding async I/O to complete. */ if (spa->spa_async_zio_root != NULL) { - (void) zio_wait(spa->spa_async_zio_root); + for (int i = 0; i < max_ncpus; i++) + (void) zio_wait(spa->spa_async_zio_root[i]); + kmem_free(spa->spa_async_zio_root, max_ncpus * sizeof (void *)); spa->spa_async_zio_root = NULL; } @@ -2213,8 +2215,13 @@ spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config, /* * Create "The Godfather" zio to hold all async IOs */ - spa->spa_async_zio_root = zio_root(spa, NULL, NULL, - ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER); + spa->spa_async_zio_root = kmem_alloc(max_ncpus * sizeof (void *), + KM_SLEEP); + for (int i = 0; i < max_ncpus; i++) { + spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL, + ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | + ZIO_FLAG_GODFATHER); + } /* * Parse the configuration into a vdev tree. We explicitly set the @@ -3567,8 +3574,13 @@ spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props, /* * Create "The Godfather" zio to hold all async IOs */ - spa->spa_async_zio_root = zio_root(spa, NULL, NULL, - ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER); + spa->spa_async_zio_root = kmem_alloc(max_ncpus * sizeof (void *), + KM_SLEEP); + for (int i = 0; i < max_ncpus; i++) { + spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL, + ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | + ZIO_FLAG_GODFATHER); + } /* * Create the root vdev. diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/spa_impl.h b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/spa_impl.h index a1943e72b038..40f5b06f1e3d 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/spa_impl.h +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/spa_impl.h @@ -206,7 +206,8 @@ struct spa { uint64_t spa_failmode; /* failure mode for the pool */ uint64_t spa_delegation; /* delegation on/off */ list_t spa_config_list; /* previous cache file(s) */ - zio_t *spa_async_zio_root; /* root of all async I/O */ + /* per-CPU array of root of async I/O: */ + zio_t **spa_async_zio_root; zio_t *spa_suspend_zio_root; /* root of all suspended I/O */ kmutex_t spa_suspend_lock; /* protects suspend_zio_root */ kcondvar_t spa_suspend_cv; /* notification of resume */ diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c index 895b0cecf2c6..3586f8723bd7 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c @@ -1457,7 +1457,7 @@ zio_nowait(zio_t *zio) */ spa_t *spa = zio->io_spa; - zio_add_child(spa->spa_async_zio_root, zio); + zio_add_child(spa->spa_async_zio_root[CPU_SEQID], zio); } zio_execute(zio);