mirror_zfs/module/os/freebsd/zfs
Shaan Nobee 411f4a018d
Speed up WB_SYNC_NONE when a WB_SYNC_ALL occurs simultaneously
Page writebacks with WB_SYNC_NONE can take several seconds to complete 
since they wait for the transaction group to close before being 
committed. This is usually not a problem since the caller does not 
need to wait. However, if we're simultaneously doing a writeback 
with WB_SYNC_ALL (e.g via msync), the latter can block for several 
seconds (up to zfs_txg_timeout) due to the active WB_SYNC_NONE 
writeback since it needs to wait for the transaction to complete 
and the PG_writeback bit to be cleared.

This commit deals with 2 cases:

- No page writeback is active. A WB_SYNC_ALL page writeback starts 
  and even completes. But when it's about to check if the PG_writeback 
  bit has been cleared, another writeback with WB_SYNC_NONE starts. 
  The sync page writeback ends up waiting for the non-sync page 
  writeback to complete.

- A page writeback with WB_SYNC_NONE is already active when a 
  WB_SYNC_ALL writeback starts. The WB_SYNC_ALL writeback ends up 
  waiting for the WB_SYNC_NONE writeback.

The fix works by carefully keeping track of active sync/non-sync 
writebacks and committing when beneficial.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Shaan Nobee <sniper111@gmail.com>
Closes #12662
Closes #12790
2022-05-03 13:23:26 -07:00
..
abd_os.c Remove bcopy(), bzero(), bcmp() 2022-03-15 15:13:42 -07:00
arc_os.c Clean up CSTYLEDs 2022-01-26 11:38:52 -08:00
crypto_os.c Forbid b{copy,zero,cmp}(). Don't include <strings.h> for <string.h> 2022-03-15 15:13:48 -07:00
dmu_os.c Remove bcopy(), bzero(), bcmp() 2022-03-15 15:13:42 -07:00
hkdf.c Remove bcopy(), bzero(), bcmp() 2022-03-15 15:13:42 -07:00
kmod_core.c zfs: add missed dependency of zfs module on zlib 2021-08-13 13:42:45 -07:00
spa_os.c Add spa _os() hooks 2022-02-15 15:54:25 -08:00
sysctl_os.c Clean up CSTYLEDs 2022-01-26 11:38:52 -08:00
vdev_file.c module/*.ko: prune .data, global .rodata 2022-01-14 15:37:55 -08:00
vdev_geom.c FreeBSD: Fix translation from ABD to physical pages 2022-04-20 16:05:38 -07:00
vdev_label_os.c FreeBSD: Clean up ASSERT/VERIFY use in module 2021-04-30 16:36:10 -07:00
zfs_acl.c Fix ACL checks for NFS kernel server 2022-03-18 06:47:57 -06:00
zfs_ctldir.c Remove bcopy(), bzero(), bcmp() 2022-03-15 15:13:42 -07:00
zfs_debug.c Clean up CSTYLEDs 2022-01-26 11:38:52 -08:00
zfs_dir.c Clean up use of zfs_log_create in zfs_dir 2021-05-07 15:13:10 -07:00
zfs_file_os.c FreeBSD: Catch up with recent VFS changes 2021-10-25 09:46:28 -07:00
zfs_ioctl_compat.c FreeBSD: Fix legacy compat for platform IOCs 2020-09-30 13:25:50 -07:00
zfs_ioctl_os.c libzfs: On FreeBSD, use MNT_NOWAIT with getfsstat 2021-06-08 07:36:43 -06:00
zfs_racct.c module: zfs: fix unused, remove argsused 2021-12-23 09:42:47 -08:00
zfs_vfsops.c module: mark arguments used 2022-02-18 09:34:03 -08:00
zfs_vnops_os.c FreeBSD: Clean up the use of ioflags 2022-05-02 16:26:28 -07:00
zfs_znode.c Speed up WB_SYNC_NONE when a WB_SYNC_ALL occurs simultaneously 2022-05-03 13:23:26 -07:00
zio_crypt.c Remove bcopy(), bzero(), bcmp() 2022-03-15 15:13:42 -07:00
zvol_os.c FreeBSD: Clean up the use of ioflags 2022-05-02 16:26:28 -07:00