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author | hselasky <hselasky@FreeBSD.org> | 2015-01-15 15:32:30 +0000 |
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committer | hselasky <hselasky@FreeBSD.org> | 2015-01-15 15:32:30 +0000 |
commit | a9eed96a6bda13eed9a6320cbe91959c48407fb8 (patch) | |
tree | ebd024c7dff919c77c0677d25786d9d0e272bcb1 /sys/sys/_callout.h | |
parent | 535e5620c99b6193aa79f6f7f2604a6a1443672f (diff) | |
download | FreeBSD-src-a9eed96a6bda13eed9a6320cbe91959c48407fb8.zip FreeBSD-src-a9eed96a6bda13eed9a6320cbe91959c48407fb8.tar.gz |
Major callout subsystem cleanup and rewrite:
- Close a migration race where callout_reset() failed to set the
CALLOUT_ACTIVE flag.
- Callout callback functions are now allowed to be protected by
spinlocks.
- Switching the callout CPU number cannot always be done on a
per-callout basis. See the updated timeout(9) manual page for more
information.
- The timeout(9) manual page has been updated to reflect how all the
functions inside the callout API are working. The manual page has
been made function oriented to make it easier to deduce how each of
the functions making up the callout API are working without having
to first read the whole manual page. Group all functions into a
handful of sections which should give a quick top-level overview
when the different functions should be used.
- The CALLOUT_SHAREDLOCK flag and its functionality has been removed
to reduce the complexity in the callout code and to avoid problems
about atomically stopping callouts via callout_stop(). If someone
needs it, it can be re-added. From my quick grep there are no
CALLOUT_SHAREDLOCK clients in the kernel.
- A new callout API function named "callout_drain_async()" has been
added. See the updated timeout(9) manual page for a complete
description.
- Update the callout clients in the "kern/" folder to use the callout
API properly, like cv_timedwait(). Previously there was some custom
sleepqueue code in the callout subsystem, which has been removed,
because we now allow callouts to be protected by spinlocks. This
allows us to tear down the callout like done with regular mutexes,
and a "td_slpmutex" has been added to "struct thread" to atomically
teardown the "td_slpcallout". Further the "TDF_TIMOFAIL" and
"SWT_SLEEPQTIMO" states can now be completely removed. Currently
they are marked as available and will be cleaned up in a follow up
commit.
- Bump the __FreeBSD_version to indicate kernel modules need
recompilation.
- There has been several reports that this patch "seems to squash a
serious bug leading to a callout timeout and panic".
Kernel build testing: all architectures were built
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D1438
Sponsored by: Mellanox Technologies
Reviewed by: jhb, adrian, sbruno and emaste
Diffstat (limited to 'sys/sys/_callout.h')
-rw-r--r-- | sys/sys/_callout.h | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/sys/sys/_callout.h b/sys/sys/_callout.h index e186aec..f58a383 100644 --- a/sys/sys/_callout.h +++ b/sys/sys/_callout.h @@ -46,19 +46,30 @@ LIST_HEAD(callout_list, callout); SLIST_HEAD(callout_slist, callout); TAILQ_HEAD(callout_tailq, callout); +typedef void callout_func_t(void *); + +struct callout_args { + sbintime_t time; /* absolute time for the event */ + sbintime_t precision; /* delta allowed wrt opt */ + void *arg; /* function argument */ + callout_func_t *func; /* function to call */ + int flags; /* flags passed to callout_reset() */ + int cpu; /* CPU we're scheduled on */ +}; + struct callout { union { LIST_ENTRY(callout) le; SLIST_ENTRY(callout) sle; TAILQ_ENTRY(callout) tqe; } c_links; - sbintime_t c_time; /* ticks to the event */ + sbintime_t c_time; /* absolute time for the event */ sbintime_t c_precision; /* delta allowed wrt opt */ void *c_arg; /* function argument */ - void (*c_func)(void *); /* function to call */ - struct lock_object *c_lock; /* lock to handle */ + callout_func_t *c_func; /* function to call */ + struct lock_object *c_lock; /* callback lock */ int c_flags; /* state of this entry */ - volatile int c_cpu; /* CPU we're scheduled on */ + int c_cpu; /* CPU we're scheduled on */ }; #endif |