mirror_zfs/include/sys
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
..
crypto Drop unnecessary srcdir paths 2020-06-24 18:20:18 -07:00
fm Drop unnecessary srcdir paths 2020-06-24 18:20:18 -07:00
fs Drop unnecessary srcdir paths 2020-06-24 18:20:18 -07:00
lua Drop unnecessary srcdir paths 2020-06-24 18:20:18 -07:00
sysevent Drop unnecessary srcdir paths 2020-06-24 18:20:18 -07:00
abd_impl.h Removing ZERO_PAGE abd_alloc_zero_scatter 2020-06-10 17:54:11 -07:00
abd.h Add abd_cache_reap_now for abd_chunk_cache users 2020-06-17 21:44:13 -07:00
aggsum.h Reduce number of atomic_add() calls in aggsum 2020-02-06 13:21:06 -08:00
arc_impl.h ARC shrinking blocks reads/writes 2020-06-26 10:42:27 -07:00
arc.h Improve compatibility with C++ consumers 2020-06-06 12:54:04 -07:00
avl_impl.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
avl.h Restore avl_update() calls and related functions 2020-06-03 09:49:32 -07:00
bitops.h Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
blkptr.h OpenZFS 8067 - zdb should be able to dump literal embedded block pointer 2017-07-07 11:28:01 -07:00
bplist.h Fast Clone Deletion 2019-07-26 10:54:14 -07:00
bpobj.h Fast Clone Deletion 2019-07-26 10:54:14 -07:00
bptree.h Illumos 4914 - zfs on-disk bookmark structure should be named *_phys_t 2014-08-06 14:48:41 -07:00
bqueue.h Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
btree.h Fix typos 2020-06-09 21:24:09 -07:00
dataset_kstats.h port async unlinked drain from illumos-nexenta 2019-02-12 10:41:15 -08:00
dbuf.h Few microoptimizations to dbuf layer 2020-02-05 11:08:44 -08:00
ddt.h Fix gcc10.1 truncation error 2020-06-13 11:02:00 -07:00
dmu_impl.h Prevent race condition in dnode_dest (#10101) 2020-03-12 10:25:56 -07:00
dmu_objset.h File incorrectly zeroed when receiving incremental stream that toggles -L 2020-06-09 10:41:01 -07:00
dmu_recv.h remove unneeded member drc_err of dmu_recv_cookie_t 2020-05-14 12:10:29 -07:00
dmu_redact.h Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
dmu_send.h Add 'zfs send --saved' flag 2020-01-10 10:16:58 -08:00
dmu_traverse.h Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
dmu_tx.h Linux 4.19-rc3+ compat: Remove refcount_t compat 2018-09-26 10:29:26 -07:00
dmu_zfetch.h Replace zf_rwlock with a mutex 2019-07-25 11:57:58 -07:00
dmu.h File incorrectly zeroed when receiving incremental stream that toggles -L 2020-06-09 10:41:01 -07:00
dnode.h Prevent race condition in dnode_dest (#10101) 2020-03-12 10:25:56 -07:00
dsl_bookmark.h zcp: add zfs.sync.bookmark 2020-02-11 13:19:17 -08:00
dsl_crypt.h dmu_objset_from_ds must be called with dp_config_rwlock held 2020-03-12 10:55:02 -07:00
dsl_dataset.h Improve compatibility with C++ consumers 2020-06-06 12:54:04 -07:00
dsl_deadlist.h Add fast path for zfs_ioc_space_snaps() handling of empty_bpobj 2019-08-20 11:34:52 -07:00
dsl_deleg.h Remove code for zfs remap 2019-06-24 16:44:01 -07:00
dsl_destroy.h Fast Clone Deletion 2019-07-26 10:54:14 -07:00
dsl_dir.h Add 'zfs wait' command 2020-04-01 10:02:06 -07:00
dsl_pool.h Eliminate Linux specific inode usage from common code 2019-12-11 11:53:57 -08:00
dsl_prop.h Support inheriting properties in channel programs 2020-01-22 17:03:17 -08:00
dsl_scan.h Remove limit on number of async zio_frees of non-dedup blocks 2020-02-14 08:39:46 -08:00
dsl_synctask.h OpenZFS 9425 - channel programs can be interrupted 2019-06-22 16:51:46 -07:00
dsl_userhold.h Illumos #3740 2013-11-04 11:17:48 -08:00
edonr.h OpenZFS 4185 - add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R 2016-10-03 14:51:15 -07:00
efi_partition.h Fix typos in include/ 2019-08-30 09:53:15 -07:00
frame.h Suppress incorrect objtool warnings 2017-12-07 10:28:50 -08:00
hkdf.h Encryption patch follow-up 2017-10-11 16:54:48 -04:00
Makefile.am Drop unnecessary srcdir paths 2020-06-24 18:20:18 -07:00
metaslab_impl.h Use a struct to organize metaslab-group-allocator fields 2020-04-22 10:26:56 -07:00
metaslab.h Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
mmp.h Add zfs_multihost_interval tunable handler for FreeBSD 2020-06-23 13:32:42 -07:00
mntent.h Add FreeBSD required defines to mntent.h 2019-11-30 15:49:09 -08:00
mod.h Wrap Linux module macros 2019-11-01 10:41:03 -07:00
multilist.h Avoid extra taskq_dispatch() calls by DMU 2019-06-25 12:03:38 -07:00
note.h Update build system and packaging 2018-05-29 16:00:33 -07:00
nvpair_impl.h OpenZFS 9580 - Add a hash-table on top of nvlist to speed-up operations 2018-07-30 11:30:03 -07:00
nvpair.h Add new fnvlist_lookup_* functions 2018-10-03 15:30:55 -07:00
objlist.h Implement Redacted Send/Receive 2019-06-19 09:48:12 -07:00
pathname.h Disable unused pathname::pn_path* (unneeded in Linux) 2019-07-15 13:57:56 -07:00
qat.h QAT related bug fixes 2019-09-12 13:33:44 -07:00
range_tree.h Improve compatibility with C++ consumers 2020-06-06 12:54:04 -07:00
refcount.h Prevent race in blkptr_verify against device removal 2019-08-13 21:24:43 -06:00
rrwlock.h OpenZFS restructuring - zfs_ioctl 2019-09-27 10:46:28 -07:00
sa_impl.h Linux 4.19-rc3+ compat: Remove refcount_t compat 2018-09-26 10:29:26 -07:00
sa.h Fix typos in include/ 2019-08-30 09:53:15 -07:00
skein.h OpenZFS 4185 - add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R 2016-10-03 14:51:15 -07:00
spa_boot.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
spa_checkpoint.h Serialize ZTHR operations to eliminate races 2019-01-13 10:09:46 -08:00
spa_checksum.h Implementation of AVX2 optimized Fletcher-4 2016-06-02 14:30:51 -07:00
spa_impl.h Add separate field for indicating that spa is in middle of split 2020-04-09 09:59:31 -07:00
spa_log_spacemap.h Log Spacemap Project 2019-07-16 10:11:49 -07:00
spa.h Trim L2ARC 2020-06-09 10:15:08 -07:00
space_map.h Log Spacemap Project 2019-07-16 10:11:49 -07:00
space_reftree.h Reduce loaded range tree memory usage 2019-10-09 10:36:03 -07:00
sysevent.h OpenZFS 6939 - add sysevents to zfs core for commands 2017-07-12 21:28:13 -07:00
txg_impl.h Fix typos in include/ 2019-08-30 09:53:15 -07:00
txg.h OpenZFS 9425 - channel programs can be interrupted 2019-06-22 16:51:46 -07:00
u8_textprep_data.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
u8_textprep.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
uberblock_impl.h MMP interval and fail_intervals in uberblock 2019-03-21 12:47:57 -07:00
uberblock.h Multi-modifier protection (MMP) 2017-07-13 13:54:00 -04:00
uio_impl.h deadlock between mm_sem and tx assign in zfs_write() and page fault 2018-10-16 11:11:24 -07:00
unique.h Illumos #3742 2013-11-04 10:55:25 -08:00
uuid.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
vdev_disk.h Make struct vdev_disk_t be platform private 2020-06-16 11:43:33 -07:00
vdev_file.h Add zfs_file_* interface, remove vnodes 2019-11-21 09:32:57 -08:00
vdev_impl.h Trim L2ARC 2020-06-09 10:15:08 -07:00
vdev_indirect_births.h OpenZFS 7614, 9064 - zfs device evacuation/removal 2018-04-14 12:16:17 -07:00
vdev_indirect_mapping.h OpenZFS 7614, 9064 - zfs device evacuation/removal 2018-04-14 12:16:17 -07:00
vdev_initialize.h Add TRIM support 2019-03-29 09:13:20 -07:00
vdev_raidz_impl.h Add prototypes 2020-06-18 12:21:32 -07:00
vdev_raidz.h Linux 5.0 compat: SIMD compatibility 2019-07-12 09:31:20 -07:00
vdev_removal.h panic in removal_remap test on 4K devices 2019-06-13 13:12:39 -07:00
vdev_trim.h Trim L2ARC 2020-06-09 10:15:08 -07:00
vdev.h Improve compatibility with C++ consumers 2020-06-06 12:54:04 -07:00
xvattr.h Linux 4.18 compat: inode timespec -> timespec64 2018-06-19 21:51:18 -07:00
zap_impl.h OpenZFS 7793 - ztest fails assertion in dmu_tx_willuse_space 2017-03-07 09:51:59 -08:00
zap_leaf.h Fix ENOSPC in "Handle zap_add() failures in ..." 2018-04-18 14:19:50 -07:00
zap.h fat zap should prefetch when iterating 2019-06-12 13:13:09 -07:00
zcp_global.h OpenZFS 7431 - ZFS Channel Programs 2018-02-08 15:28:18 -08:00
zcp_iter.h OpenZFS 7431 - ZFS Channel Programs 2018-02-08 15:28:18 -08:00
zcp_prop.h OpenZFS 7431 - ZFS Channel Programs 2018-02-08 15:28:18 -08:00
zcp_set.h Support setting user properties in a channel program 2020-02-14 13:41:42 -08:00
zcp.h async zvol minor node creation interferes with receive 2020-02-03 09:33:14 -08:00
zfeature.h Revert "zhack: Add 'feature disable' command" 2016-05-17 11:52:07 -07:00
zfs_acl.h Return an error code from zfs_acl_chmod_setattr 2019-11-01 10:19:11 -07:00
zfs_context.h Remove dead code 2020-06-18 12:21:18 -07:00
zfs_debug.h Remove sdt.h 2019-10-25 13:38:37 -07:00
zfs_delay.h Update build system and packaging 2018-05-29 16:00:33 -07:00
zfs_file.h Re-share zfsdev_getminor and zfs_onexit_fd_hold 2020-02-28 14:50:32 -08:00
zfs_fuid.h Replace sprintf()->snprintf() and strcpy()->strlcpy() 2020-06-07 11:42:12 -07:00
zfs_ioctl_impl.h Restore support for in-kernel ZFS ioctls 2020-06-08 13:57:22 -07:00
zfs_ioctl.h drr_begin: can't forward declare untagged struct 2020-06-16 11:57:04 -07:00
zfs_onexit.h Remove deduplicated send/receive code 2020-04-23 10:06:57 -07:00
zfs_project.h Minor diff reduction with ZoF in include/sys 2019-11-27 11:11:03 -08:00
zfs_quota.h File incorrectly zeroed when receiving incremental stream that toggles -L 2020-06-09 10:41:01 -07:00
zfs_ratelimit.h Change checksum & IO delay ratelimit values 2018-03-04 17:34:51 -08:00
zfs_rlock.h Prefix struct rangelock 2019-11-01 10:37:33 -07:00
zfs_sa.h Project Quota on ZFS 2018-02-13 14:54:54 -08:00
zfs_stat.h Support custom build directories and move includes 2010-09-08 12:38:56 -07:00
zfs_sysfs.h Fix in-kernel sysfs entries 2018-09-06 21:44:52 -07:00
zfs_znode.h Fix typos 2020-06-09 21:24:09 -07:00
zil_impl.h make zil max block size tunable 2019-06-10 11:48:42 -07:00
zil.h Add prototypes 2020-06-18 12:21:32 -07:00
zio_checksum.h Remove dependency on linear ABD 2017-03-29 12:24:51 -07:00
zio_compress.h lz4_decompress_abd declared but not defined 2019-06-13 13:14:34 -07:00
zio_crypt.h Fix typos 2020-06-09 21:24:09 -07:00
zio_impl.h Fix typos in include/ 2019-08-30 09:53:15 -07:00
zio_priority.h Add TRIM support 2019-03-29 09:13:20 -07:00
zio.h Improve compatibility with C++ consumers 2020-06-06 12:54:04 -07:00
zrlock.h OpenZFS 6328 - Fix cstyle errors in zfs codebase 2017-01-12 09:42:11 -08:00
zthr.h Fast Clone Deletion 2019-07-26 10:54:14 -07:00
zvol_impl.h Connect dataset_kstats for FreeBSD 2020-06-05 17:17:02 -07:00
zvol.h async zvol minor node creation interferes with receive 2020-02-03 09:33:14 -08:00