freebsd-skq/sys/dev/xen
mjg bcfa67ab8b 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
..
balloon
blkback vfs: introduce v_irflag and make v_type smaller 2019-12-08 21:30:04 +00:00
blkfront
console
control xen/ctrl: acknowledge all control requests 2019-10-01 08:21:41 +00:00
debug
evtchn
gntdev (4/6) Protect page valid with the busy lock. 2019-10-15 03:45:41 +00:00
grant_table
netback Remove an unneeded include of opt_sctp.h. 2019-10-11 17:23:23 +00:00
netfront
pci
pcifront
privcmd (4/6) Protect page valid with the busy lock. 2019-10-15 03:45:41 +00:00
pvcpu
timer
xenpci
xenstore