Date: Fri, 27 Dec 2019 12:33:56 +0100 From: "Ronald Klop" <ronald-lists@klop.ws> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org, "Mateusz Guzik" <mjg@freebsd.org> Subject: Re: svn commit: r356120 - head/sys/security/mac Message-ID: <op.0dgfqujxkndu52@sjakie> In-Reply-To: <201912271123.xBRBNWow013539@repo.freebsd.org> References: <201912271123.xBRBNWow013539@repo.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, 27 Dec 2019 12:23:32 +0100, Mateusz Guzik <mjg@freebsd.org> wrote: > Author: mjg > Date: Fri Dec 27 11:23:32 2019 > New Revision: 356120 > URL: https://svnweb.freebsd.org/changeset/base/356120 > > Log: > mac: use a sleepable rmlock instead of an sx lock > If any non-static modules are loaded (and mac_ntpd tends to be), the > lock is > taken all the time al over the kernel. On platforms like arm64 this > results in > an avoidable significant performance degradation. Since write-locking > is almost > never needed, use a primitive optimized towards read-locking. > Sample result of building the kernel on tmpfs 11 times: > stock 11142.80s user 6704.44s system 4924% cpu 6:02.42 total > patched 11118.95s user 2374.94s system 4547% cpu 4:56.71 total Wow, this looks like a winner. Ronald. > > Modified: > head/sys/security/mac/mac_framework.c > > Modified: head/sys/security/mac/mac_framework.c > ============================================================================== > --- head/sys/security/mac/mac_framework.c Fri Dec 27 11:19:57 > 2019 (r356119) > +++ head/sys/security/mac/mac_framework.c Fri Dec 27 11:23:32 > 2019 (r356120) > @@ -176,6 +176,7 @@ MALLOC_DEFINE(M_MACTEMP, "mactemp", "MAC temporary > lab > #ifndef MAC_STATIC > static struct rmlock mac_policy_rm; /* Non-sleeping entry points. */ > static struct sx mac_policy_sx; /* Sleeping entry points. */ > +static struct rmslock mac_policy_rms; > #endif > struct mac_policy_list_head mac_policy_list; > @@ -209,7 +210,7 @@ mac_policy_slock_sleep(void) > if (!mac_late) > return; > - sx_slock(&mac_policy_sx); > + rms_rlock(&mac_policy_rms); > #endif > } > @@ -233,7 +234,7 @@ mac_policy_sunlock_sleep(void) > if (!mac_late) > return; > - sx_sunlock(&mac_policy_sx); > + rms_runlock(&mac_policy_rms); > #endif > } > @@ -249,6 +250,7 @@ mac_policy_xlock(void) > return; > sx_xlock(&mac_policy_sx); > + rms_wlock(&mac_policy_rms); > rm_wlock(&mac_policy_rm); > #endif > } > @@ -262,6 +264,7 @@ mac_policy_xunlock(void) > return; > rm_wunlock(&mac_policy_rm); > + rms_wunlock(&mac_policy_rms); > sx_xunlock(&mac_policy_sx); > #endif > } > @@ -294,6 +297,7 @@ mac_init(void) > rm_init_flags(&mac_policy_rm, "mac_policy_rm", RM_NOWITNESS | > RM_RECURSE); > sx_init_flags(&mac_policy_sx, "mac_policy_sx", SX_NOWITNESS); > + rms_init(&mac_policy_rms, "mac_policy_rms"); > #endif > } > _______________________________________________ > svn-src-all@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/svn-src-all > To unsubscribe, send any mail to "svn-src-all-unsubscribe@freebsd.org"
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?op.0dgfqujxkndu52>