freebsd-nq/sys/fs
Konstantin Belousov 5c7bebf961 The process spin lock currently has the following distinct uses:
- Threads lifetime cycle, in particular, counting of the threads in
  the process, and interlocking with process mutex and thread lock.
  The main reason of this is that turnstile locks are after thread
  locks, so you e.g. cannot unlock blockable mutex (think process
  mutex) while owning thread lock.

- Virtual and profiling itimers, since the timers activation is done
  from the clock interrupt context.  Replace the p_slock by p_itimmtx
  and PROC_ITIMLOCK().

- Profiling code (profil(2)), for similar reason.  Replace the p_slock
  by p_profmtx and PROC_PROFLOCK().

- Resource usage accounting.  Need for the spinlock there is subtle,
  my understanding is that spinlock blocks context switching for the
  current thread, which prevents td_runtime and similar fields from
  changing (updates are done at the mi_switch()).  Replace the p_slock
  by p_statmtx and PROC_STATLOCK().

The split is done mostly for code clarity, and should not affect
scalability.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-11-26 14:10:00 +00:00
..
autofs Implement "automount -c". 2014-11-22 16:48:29 +00:00
cd9660
cuse
deadfs
devfs Fix up some session-related races in devfs. 2014-11-03 03:12:15 +00:00
ext2fs ifdef ext2_print_inode which is not really used. 2014-11-12 16:23:56 +00:00
fdescfs
fifofs
fuse
msdosfs
nandfs
nfs
nfsclient
nfsserver
nullfs
procfs The process spin lock currently has the following distinct uses: 2014-11-26 14:10:00 +00:00
pseudofs
smbfs Fix smbfs to not zero out statfs f_flags field. Previously, this 2014-11-21 06:21:39 +00:00
tmpfs
udf
unionfs