freebsd-dev/sys/fs/devfs
Mateusz Guzik abd80ddb94 vfs: introduce v_irflag and make v_type smaller
The current vnode layout is not smp-friendly by having frequently read data
avoidably sharing cachelines with very frequently modified fields. In
particular v_iflag inspected for VI_DOOMED can be found in the same line with
v_usecount. Instead make it available in the same cacheline as the v_op, v_data
and v_type which all get read all the time.

v_type is avoidably 4 bytes while the necessary data will easily fit in 1.
Shrinking it frees up 3 bytes, 2 of which get used here to introduce a new
flag field with a new value: VIRF_DOOMED.

Reviewed by:	kib, jeff
Differential Revision:	https://reviews.freebsd.org/D22715
2019-12-08 21:30:04 +00:00
..
devfs_devs.c devfs: introduce a per-dev lock to protect ->si_devsw 2019-11-30 16:46:19 +00:00
devfs_dir.c r326394 is calling malloc with M_WAITOK under a lock, revert for now 2017-11-30 14:06:54 +00:00
devfs_int.h devfs: introduce a per-dev lock to protect ->si_devsw 2019-11-30 16:46:19 +00:00
devfs_rule.c sys/fs: further adoption of SPDX licensing ID tags. 2017-11-27 15:15:37 +00:00
devfs_vfsops.c devfs: use MNTK_NOMSYNC 2019-10-13 15:41:47 +00:00
devfs_vnops.c vfs: introduce v_irflag and make v_type smaller 2019-12-08 21:30:04 +00:00
devfs.h sys/fs: further adoption of SPDX licensing ID tags. 2017-11-27 15:15:37 +00:00