Date: Tue, 31 Mar 2015 00:18:01 +0000 (UTC) From: Randall Stewart <rrs@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r280872 - in head/sys: kern sys Message-ID: <201503310018.t2V0I1o7015125@svn.freebsd.org>
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Author: rrs Date: Tue Mar 31 00:18:00 2015 New Revision: 280872 URL: https://svnweb.freebsd.org/changeset/base/280872 Log: Adopt jhb's suggested changes, updated comments and callout_migration() moving to kern/kern_timeout.c This does *not* address his -1 -> NOCPU comment. Sponsored by: Netflix Inc. Modified: head/sys/kern/kern_timeout.c head/sys/sys/callout.h Modified: head/sys/kern/kern_timeout.c ============================================================================== --- head/sys/kern/kern_timeout.c Tue Mar 31 00:15:27 2015 (r280871) +++ head/sys/kern/kern_timeout.c Tue Mar 31 00:18:00 2015 (r280872) @@ -167,6 +167,8 @@ struct callout_cpu { char cc_ktr_event_name[20]; }; +#define callout_migrating(c) ((c)->c_iflags & CALLOUT_DFRMIGRATION) + #define cc_exec_curr(cc, dir) cc->cc_exec_entity[dir].cc_curr #define cc_exec_next(cc) cc->cc_next #define cc_exec_cancel(cc, dir) cc->cc_exec_entity[dir].cc_cancel Modified: head/sys/sys/callout.h ============================================================================== --- head/sys/sys/callout.h Tue Mar 31 00:15:27 2015 (r280871) +++ head/sys/sys/callout.h Tue Mar 31 00:18:00 2015 (r280872) @@ -68,18 +68,18 @@ struct callout_handle { * field is the one that caller operations that may, or may not have * a lock touches i.e. callout_deactivate(). The other, the c_iflags, * is the internal flags that *must* be kept correct on which the - * callout system depend on i.e. callout_migrating() & callout_pending(), - * these are used internally by the callout system to determine which - * list and other critical internal state. Callers *should not* use the - * c_flags field directly but should use the macros! + * callout system depend on e.g. callout_pending(). + * The c_iflag is used internally by the callout system to determine which + * list the callout is on and track internal state. Callers *should not* + * use the c_flags field directly but should use the macros provided. * - * If the caller wants to keep the c_flags field sane they - * should init with a mutex *or* if using the older - * mpsafe option, they *must* lock there own lock - * before calling callout_deactivate(). + * The c_iflags field holds internal flags that are protected by internal + * locks of the callout subsystem. The c_flags field holds external flags. + * The caller must hold its own lock while manipulating or reading external + * flags via callout_active(), callout_deactivate(), callout_reset*(), or + * callout_stop() to avoid races. */ #define callout_active(c) ((c)->c_flags & CALLOUT_ACTIVE) -#define callout_migrating(c) ((c)->c_iflags & CALLOUT_DFRMIGRATION) #define callout_deactivate(c) ((c)->c_flags &= ~CALLOUT_ACTIVE) #define callout_drain(c) _callout_stop_safe(c, 1) void callout_init(struct callout *, int);
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