mirror_zfs/module/zfs
Matthew Ahrens 67c0f0dedc
ARC shrinking blocks reads/writes
ZFS registers a memory hook, `__arc_shrinker_func`, which is supposed to
allow the ARC to shrink when the kernel experiences memory pressure.
The ARC shrinker changes `arc_c` via a call to
`arc_reduce_target_size()`.  Before commit 3ec34e5527, the ARC
shrinker would also evict data from the ARC to bring `arc_size` down to
the new `arc_c`.  However, that commit (seemingly inadvertently) made it
so that the ARC shrinker no longer evicts any data or waits for eviction
to complete.

Repeated calls to the ARC shrinker can reduce `arc_c` drastically, often
all the way to `arc_c_min`.  Since it doesn't wait for the actual
eviction of data from the ARC, this creates a situation where `arc_size`
is more than `arc_c` for the several seconds/minutes it takes for
`arc_adjust_zthr` to evict data from the ARC.  During this time,
arc_get_data_impl() will block, so ZFS can't process read/write requests
(e.g. from iSCSI, NFS, or read/write syscalls).

To ensure that `arc_c` doesn't shrink faster than the adjust thread can
keep up, this commit makes the ARC shrinker wait for the eviction to
complete, resulting in similar behavior to what we had before commit
3ec34e5527.

Note: commit 3ec34e5527 is `OpenZFS 9284 - arc_reclaim_thread
has 2 jobs` and was integrated in December 2018, and is part of ZoL
0.8.x but not 0.7.x.

Additionally, when the ARC size is reduced drastically, the
`arc_adjust_zthr` can be on-CPU for many seconds without blocking.  Any
threads that are bound to the same CPU that arc_adjust_zthr is running
on will not able to run for a long time.

To ensure that CPU-bound threads can make progress, this commit changes
`arc_evict_state_impl()` make a voluntary preemption call,
`cond_resched()`.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-70703
Closes #10496
2020-06-26 10:42:27 -07:00
..
abd.c Fix typos 2020-06-09 21:24:09 -07:00
aggsum.c Reduce number of atomic_add() calls in aggsum 2020-02-06 13:21:06 -08:00
arc.c ARC shrinking blocks reads/writes 2020-06-26 10:42:27 -07:00
blkptr.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
bplist.c Fast Clone Deletion 2019-07-26 10:54:14 -07:00
bpobj.c Add subcommand to wait for background zfs activity to complete 2019-09-13 18:09:06 -07:00
bptree.c Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
bqueue.c Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
btree.c Fix typos 2020-06-09 21:24:09 -07:00
dataset_kstats.c Fix panic on DilOS with kstat per dataset statistics 2019-09-03 12:12:31 -07:00
dbuf_stats.c Mark functions as static 2020-06-18 12:20:38 -07:00
dbuf.c Mark functions as static 2020-06-18 12:20:38 -07:00
ddt_zap.c Refactor dnode dirty context from dbuf_dirty 2020-02-26 16:09:17 -08:00
ddt.c Remove dead code 2020-06-18 12:21:18 -07:00
dmu_diff.c Mark write_record static 2019-12-03 09:51:44 -08:00
dmu_object.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
dmu_objset.c Mark functions as static 2020-06-18 12:20:38 -07:00
dmu_recv.c File incorrectly zeroed when receiving incremental stream that toggles -L 2020-06-09 10:41:01 -07:00
dmu_redact.c dmu_objset_from_ds must be called with dp_config_rwlock held 2020-03-12 10:55:02 -07:00
dmu_send.c Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-06-07 11:42:12 -07:00
dmu_traverse.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
dmu_tx.c Refactor dnode dirty context from dbuf_dirty 2020-02-26 16:09:17 -08:00
dmu_zfetch.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
dmu.c Mark functions as static 2020-06-18 12:20:38 -07:00
dnode_sync.c Convert dbuf dirty record record list to a list_t 2020-02-05 11:07:19 -08:00
dnode.c Prevent race condition in dnode_dest (#10101) 2020-03-12 10:25:56 -07:00
dsl_bookmark.c Fix typos 2020-06-09 21:24:09 -07:00
dsl_crypt.c Mark functions as static 2020-06-18 12:20:38 -07:00
dsl_dataset.c Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-06-07 11:42:12 -07:00
dsl_deadlist.c Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
dsl_deleg.c Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
dsl_destroy.c Memory leak in dsl_destroy_snapshots_nvl error case 2020-05-26 16:13:41 -07:00
dsl_dir.c Mark functions as static 2020-06-18 12:20:38 -07:00
dsl_pool.c Mark functions as static 2020-06-18 12:20:38 -07:00
dsl_prop.c Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-06-07 11:42:12 -07:00
dsl_scan.c Mark functions as static 2020-06-18 12:20:38 -07:00
dsl_synctask.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
dsl_userhold.c Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-06-07 11:42:12 -07:00
edonr_zfs.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
fm.c Enable zpool events tunables and tests on FreeBSD 2020-02-18 11:22:56 -08:00
gzip.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
hkdf.c Encryption patch follow-up 2017-10-11 16:54:48 -04:00
lz4.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
lzjb.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
Makefile.in Cleanup linux module kbuild files 2020-06-10 09:24:15 -07:00
metaslab.c Mark functions as static 2020-06-18 12:20:38 -07:00
mmp.c Add zfs_multihost_interval tunable handler for FreeBSD 2020-06-23 13:32:42 -07:00
multilist.c Enable use of DTRACE_PROBE* macros in "spl" module 2019-11-01 13:13:43 -07:00
objlist.c Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
pathname.c Disable unused pathname::pn_path* (unneeded in Linux) 2019-07-15 13:57:56 -07:00
range_tree.c Function name and comment updates 2019-10-11 10:13:21 -07:00
refcount.c Disable user space reference tracking 2020-04-13 10:51:44 -07:00
rrwlock.c Enable use of DTRACE_PROBE* macros in "spl" module 2019-11-01 13:13:43 -07:00
sa.c Mark functions as static 2020-06-18 12:20:38 -07:00
sha256.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
skein_zfs.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
spa_boot.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
spa_checkpoint.c Refactor dnode dirty context from dbuf_dirty 2020-02-26 16:09:17 -08:00
spa_config.c Add zfs_file_* interface, remove vnodes 2019-11-21 09:32:57 -08:00
spa_errlog.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
spa_history.c Make spa_history_zone platform-dependent in kernel 2020-03-02 09:43:30 -08:00
spa_log_spacemap.c Make module tunables cross platform 2019-09-05 14:49:49 -07:00
spa_misc.c Mark functions as static 2020-06-18 12:20:38 -07:00
spa.c Mark functions as static 2020-06-18 12:20:38 -07:00
space_map.c Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
space_reftree.c Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
THIRDPARTYLICENSE.cityhash OpenZFS 8484 - Implement aggregate sum and use for arc counters 2018-06-06 09:35:59 -07:00
THIRDPARTYLICENSE.cityhash.descrip OpenZFS 8484 - Implement aggregate sum and use for arc counters 2018-06-06 09:35:59 -07:00
txg.c Use boot_ncpus in place of max_ncpus in taskq_create 2020-05-20 10:07:21 -07:00
uberblock.c MMP interval and fail_intervals in uberblock 2019-03-21 12:47:57 -07:00
unique.c Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
vdev_cache.c Replace ASSERTV macro with compiler annotation 2019-12-05 12:37:00 -08:00
vdev_indirect_births.c Fixes: #8934 Large kmem_alloc 2019-07-10 15:54:49 -07:00
vdev_indirect_mapping.c Replace ASSERTV macro with compiler annotation 2019-12-05 12:37:00 -08:00
vdev_indirect.c Mark functions as static 2020-06-18 12:20:38 -07:00
vdev_initialize.c Upstream: add missing thread_exit() 2020-05-14 15:58:09 -07:00
vdev_label.c Mark functions as static 2020-06-18 12:20:38 -07:00
vdev_mirror.c Avoid some crashes when importing a pool with corrupt metadata 2019-12-26 10:57:05 -08:00
vdev_missing.c Update vdev_ops_t from illumos 2019-06-20 18:29:02 -07:00
vdev_queue.c Mark functions as static 2020-06-18 12:20:38 -07:00
vdev_raidz_math_aarch64_neon_common.h Minor performance fix for NEON RAID-Z 2019-12-17 19:34:52 -08:00
vdev_raidz_math_aarch64_neon.c Linux 5.0 compat: SIMD compatibility 2019-07-12 09:31:20 -07:00
vdev_raidz_math_aarch64_neonx2.c Linux 5.0 compat: SIMD compatibility 2019-07-12 09:31:20 -07:00
vdev_raidz_math_avx2.c OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -07:00
vdev_raidz_math_avx512bw.c OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -07:00
vdev_raidz_math_avx512f.c Make clang happy with vdev_raidz_ code 2019-10-10 09:45:37 -07:00
vdev_raidz_math_impl.h Fix const-correctness in raidz math 2020-02-03 10:52:41 -08:00
vdev_raidz_math_powerpc_altivec_common.h Add AltiVec RAID-Z 2020-01-23 11:01:24 -08:00
vdev_raidz_math_powerpc_altivec.c Fix typos 2020-06-09 21:24:09 -07:00
vdev_raidz_math_scalar.c Linux 5.3: Fix switch() fall though compiler errors 2019-08-21 09:29:23 -07:00
vdev_raidz_math_sse2.c Make clang happy with vdev_raidz_ code 2019-10-10 09:45:37 -07:00
vdev_raidz_math_ssse3.c OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -07:00
vdev_raidz_math.c Add prototypes 2020-06-18 12:21:32 -07:00
vdev_raidz.c Fix typos 2020-06-09 21:24:09 -07:00
vdev_removal.c Trim L2ARC 2020-06-09 10:15:08 -07:00
vdev_root.c Enable splitting mirrors with indirect vdevs 2020-05-06 10:32:28 -07:00
vdev_trim.c Trim L2ARC 2020-06-09 10:15:08 -07:00
vdev.c Mark functions as static 2020-06-18 12:20:38 -07:00
zap_leaf.c Refactor dnode dirty context from dbuf_dirty 2020-02-26 16:09:17 -08:00
zap_micro.c Mark functions as static 2020-06-18 12:20:38 -07:00
zap.c Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-06-07 11:42:12 -07:00
zcp_get.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
zcp_global.c OpenZFS 8600 - ZFS channel programs - snapshot 2018-02-08 15:29:24 -08:00
zcp_iter.c Fix typos in module/zfs/ 2019-09-02 17:56:41 -07:00
zcp_set.c Support setting user properties in a channel program 2020-02-14 13:41:42 -08:00
zcp_synctask.c Refactor dnode dirty context from dbuf_dirty 2020-02-26 16:09:17 -08:00
zcp.c Refactor dnode dirty context from dbuf_dirty 2020-02-26 16:09:17 -08:00
zfeature.c Replace ASSERTV macro with compiler annotation 2019-12-05 12:37:00 -08:00
zfs_byteswap.c Mark functions as static 2020-06-18 12:20:38 -07:00
zfs_fm.c Add zpool status -s (slow I/Os) and -p (parseable) 2018-11-08 16:47:24 -08:00
zfs_fuid.c Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-06-07 11:42:12 -07:00
zfs_ioctl.c Add prototypes 2020-06-18 12:21:32 -07:00
zfs_log.c Add prototypes 2020-06-18 12:21:32 -07:00
zfs_onexit.c Remove deduplicated send/receive code 2020-04-23 10:06:57 -07:00
zfs_quota.c File incorrectly zeroed when receiving incremental stream that toggles -L 2020-06-09 10:41:01 -07:00
zfs_ratelimit.c Change checksum & IO delay ratelimit values 2018-03-04 17:34:51 -08:00
zfs_replay.c Simplify FreeBSD's locking requirements in zfs_replay.c 2020-01-22 17:55:56 -08:00
zfs_rlock.c Move platform specific parts of zfs_znode.h to platform code 2019-11-06 10:54:25 -08:00
zfs_sa.c Add convenience wrappers for common uio usage 2020-06-14 10:09:55 -07:00
zil.c Mark functions as static 2020-06-18 12:20:38 -07:00
zio_checksum.c Mark functions as static 2020-06-18 12:20:38 -07:00
zio_compress.c zio_decompress_data always ASSERTs successful decompression 2019-12-10 15:51:58 -08:00
zio_inject.c Replace ASSERTV macro with compiler annotation 2019-12-05 12:37:00 -08:00
zio.c Mark functions as static 2020-06-18 12:20:38 -07:00
zle.c Add include files for prototypes 2020-06-18 12:21:25 -07:00
zrlock.c Remove dead code 2020-06-18 12:21:18 -07:00
zthr.c Fast Clone Deletion 2019-07-26 10:54:14 -07:00
zvol.c Fix typos 2020-06-09 21:24:09 -07:00