From f3b86a5fd795dcbd10dde01e27493718dd262179 Mon Sep 17 00:00:00 2001 From: Ed Schouten Date: Wed, 28 Jan 2009 19:58:05 +0000 Subject: [PATCH] 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 +++-- sys/kern/kern_jail.c | 10 ++++++---- sys/kern/kern_mib.c | 15 ++++++++------- sys/kern/kern_sysctl.c | 7 ++++--- 4 files changed, 21 insertions(+), 16 deletions(-) diff --git a/sys/fs/devfs/devfs_devs.c b/sys/fs/devfs/devfs_devs.c index 028f5c99de3..404191173e7 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)"); diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c index e4342ad7645..b87de0b9d71 100644 --- a/sys/kern/kern_jail.c +++ b/sys/kern/kern_jail.c @@ -1529,8 +1529,9 @@ sysctl_jail_list(SYSCTL_HANDLER_ARGS) return (error); } -SYSCTL_OID(_security_jail, OID_AUTO, list, CTLTYPE_STRUCT | CTLFLAG_RD, - NULL, 0, sysctl_jail_list, "S", "List of active jails"); +SYSCTL_OID(_security_jail, OID_AUTO, list, + CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, + sysctl_jail_list, "S", "List of active jails"); static int sysctl_jail_jailed(SYSCTL_HANDLER_ARGS) @@ -1542,8 +1543,9 @@ sysctl_jail_jailed(SYSCTL_HANDLER_ARGS) return (error); } -SYSCTL_PROC(_security_jail, OID_AUTO, jailed, CTLTYPE_INT | CTLFLAG_RD, - NULL, 0, sysctl_jail_jailed, "I", "Process in jail?"); +SYSCTL_PROC(_security_jail, OID_AUTO, jailed, + CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, + sysctl_jail_jailed, "I", "Process in jail?"); #ifdef DDB DB_SHOW_COMMAND(jails, db_show_jails) diff --git a/sys/kern/kern_mib.c b/sys/kern/kern_mib.c index afe0153cb49..80c1789ad8e 100644 --- a/sys/kern/kern_mib.c +++ b/sys/kern/kern_mib.c @@ -87,19 +87,19 @@ SYSCTL_NODE(, OID_AUTO, regression, CTLFLAG_RW, 0, "Regression test MIB"); #endif -SYSCTL_STRING(_kern, OID_AUTO, ident, CTLFLAG_RD, +SYSCTL_STRING(_kern, OID_AUTO, ident, CTLFLAG_RD|CTLFLAG_MPSAFE, kern_ident, 0, "Kernel identifier"); -SYSCTL_STRING(_kern, KERN_OSRELEASE, osrelease, CTLFLAG_RD, +SYSCTL_STRING(_kern, KERN_OSRELEASE, osrelease, CTLFLAG_RD|CTLFLAG_MPSAFE, osrelease, 0, "Operating system release"); SYSCTL_INT(_kern, KERN_OSREV, osrevision, CTLFLAG_RD, 0, BSD, "Operating system revision"); -SYSCTL_STRING(_kern, KERN_VERSION, version, CTLFLAG_RD, +SYSCTL_STRING(_kern, KERN_VERSION, version, CTLFLAG_RD|CTLFLAG_MPSAFE, version, 0, "Kernel version"); -SYSCTL_STRING(_kern, KERN_OSTYPE, ostype, CTLFLAG_RD, +SYSCTL_STRING(_kern, KERN_OSTYPE, ostype, CTLFLAG_RD|CTLFLAG_MPSAFE, ostype, 0, "Operating system type"); /* @@ -165,8 +165,9 @@ sysctl_kern_arnd(SYSCTL_HANDLER_ARGS) return (SYSCTL_OUT(req, buf, len)); } -SYSCTL_PROC(_kern, KERN_ARND, arandom, CTLTYPE_OPAQUE | CTLFLAG_RD, - NULL, 0, sysctl_kern_arnd, "", "arc4rand"); +SYSCTL_PROC(_kern, KERN_ARND, arandom, + CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, + sysctl_kern_arnd, "", "arc4rand"); static int sysctl_hw_physmem(SYSCTL_HANDLER_ARGS) @@ -267,7 +268,7 @@ sysctl_hostname(SYSCTL_HANDLER_ARGS) } SYSCTL_PROC(_kern, KERN_HOSTNAME, hostname, - CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_PRISON, + CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_PRISON|CTLFLAG_MPSAFE, 0, 0, sysctl_hostname, "A", "Hostname"); static int regression_securelevel_nonmonotonic = 0; diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c index ed147602bbe..515204f9bd2 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)