From 50efccc9f04a04f03e963eee6a0f24acb1b0cec9 Mon Sep 17 00:00:00 2001 From: ed Date: Wed, 28 Jan 2009 19:58:05 +0000 Subject: 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. --- sys/fs/devfs/devfs_devs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'sys/fs/devfs') diff --git a/sys/fs/devfs/devfs_devs.c b/sys/fs/devfs/devfs_devs.c index 028f5c9..4041911 100644 --- a/sys/fs/devfs/devfs_devs.c +++ b/sys/fs/devfs/devfs_devs.c @@ -103,8 +103,9 @@ sysctl_devname(SYSCTL_HANDLER_ARGS) return (error); } -SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY, - NULL, 0, sysctl_devname, "", "devname(3) handler"); +SYSCTL_PROC(_kern, OID_AUTO, devname, + CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE, + NULL, 0, sysctl_devname, "", "devname(3) handler"); SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev, CTLFLAG_RD, 0, sizeof(struct cdev), "sizeof(struct cdev)"); -- cgit v1.1