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author | ed <ed@FreeBSD.org> | 2009-01-28 19:58:05 +0000 |
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committer | ed <ed@FreeBSD.org> | 2009-01-28 19:58:05 +0000 |
commit | 50efccc9f04a04f03e963eee6a0f24acb1b0cec9 (patch) | |
tree | 1d14b0eff13e12254c67fc494563bb9db0a4586e /sys/kern/kern_sysctl.c | |
parent | 35d15d6dd37a1883bbacef0efed00f7aadee89ec (diff) | |
download | FreeBSD-src-50efccc9f04a04f03e963eee6a0f24acb1b0cec9.zip FreeBSD-src-50efccc9f04a04f03e963eee6a0f24acb1b0cec9.tar.gz |
Mark most often used sysctl's as MPSAFE.
After running a `make buildkernel', I noticed most of the Giant locks in
sysctl are only caused by a very small amount of sysctl's:
- sysctl.name2oid. This one is locked by SYSCTL_LOCK, just like
sysctl.oidfmt.
- kern.ident, kern.osrelease, kern.version, etc. These are just constant
strings.
- kern.arandom, used by the stack protector. It is already protected by
arc4_mtx.
I also saw the following sysctl's show up. Not as often as the ones
above, but still quite often:
- security.jail.jailed. Also mark security.jail.list as MPSAFE. They
don't need locking or already use allprison_lock.
- kern.devname, used by devname(3), ttyname(3), etc.
This seems to reduce Giant locking inside sysctl by ~75% in my primitive
test setup.
Diffstat (limited to 'sys/kern/kern_sysctl.c')
-rw-r--r-- | sys/kern/kern_sysctl.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c index ed14760..515204f 100644 --- a/sys/kern/kern_sysctl.c +++ b/sys/kern/kern_sysctl.c @@ -773,8 +773,8 @@ sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS) return (error); } -SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY, 0, 0, - sysctl_sysctl_name2oid, "I", ""); +SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE, + 0, 0, sysctl_sysctl_name2oid, "I", ""); static int sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) @@ -796,7 +796,8 @@ sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS) } -static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD, sysctl_sysctl_oidfmt, ""); +static SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD|CTLFLAG_MPSAFE, + sysctl_sysctl_oidfmt, ""); static int sysctl_sysctl_oiddescr(SYSCTL_HANDLER_ARGS) |