From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>, Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
John Stultz <john.stultz@linaro.org>,
Frederic Weisbecker <frederic@kernel.org>,
Anna-Maria Behnsen <anna-maria@linutronix.de>,
Christoph Hellwig <hch@lst.de>
Subject: [patch V2 20/38] posix-cpu-timers: Provide array based access to expiry cache
Date: Wed, 21 Aug 2019 21:09:07 +0200 [thread overview]
Message-ID: <20190821192921.105793824@linutronix.de> (raw)
In-Reply-To: 20190821190847.665673890@linutronix.de
Using struct task_cputime for the expiry cache is a pretty odd choice and
comes with magic defines to rename the fields for usage in the expiry
cache.
struct task_cputime is basically a u64 array with 3 members, but it has
distinct members.
The expiry cache content is different than the content of task_cputime
because
expiry[PROF] = task_cputime.stime + task_cputime.utime
expiry[VIRT] = task_cputime.utime
expiry[SCHED] = task_cputime.sum_exec_runtime
So there is no direct mapping between task_cputime and the expiry cache and
the #define based remapping is just a horrible hack.
Having the expiry cache array based allows further simplification of the
expiry code.
To avoid an all in one cleanup which is hard to review add a temporary
anonymous union into struct task_cputime which allows array based access to
it. That requires to reorder the members. Add a build time sanity check to
validate that the members are at the same place.
The union and the build time checks will be removed after conversion.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/posix-timers.h | 24 ++++++++++++++++++------
include/linux/sched/types.h | 4 ++--
kernel/time/posix-cpu-timers.c | 12 +++++++++++-
3 files changed, 31 insertions(+), 9 deletions(-)
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -65,27 +65,39 @@ static inline int clockid_to_fd(const cl
/*
* Alternate field names for struct task_cputime when used on cache
* expirations. Will go away soon.
+ *
+ * stime corresponds to CLOCKCPU_PROF
+ * utime corresponds to CLOCKCPU_VIRT
+ * sum_exex_runtime corresponds to CLOCKCPU_SCHED
+ *
+ * The ordering is currently enforced so struct task_cputime and the
+ * expiries array in struct posix_cputimers are equivalent.
*/
-#define virt_exp utime
#define prof_exp stime
+#define virt_exp utime
#define sched_exp sum_exec_runtime
#ifdef CONFIG_POSIX_TIMERS
/**
* posix_cputimers - Container for posix CPU timer related data
- * @cputime_expires: Earliest-expiration cache
+ * @cputime_expires: Earliest-expiration cache task_cputime based
+ * @expiries: Earliest-expiration cache array based
* @cpu_timers: List heads to queue posix CPU timers
*
* Used in task_struct and signal_struct
*/
struct posix_cputimers {
- struct task_cputime cputime_expires;
- struct list_head cpu_timers[CPUCLOCK_MAX];
+ /* Temporary union until all users are cleaned up */
+ union {
+ struct task_cputime cputime_expires;
+ u64 expiries[CPUCLOCK_MAX];
+ };
+ struct list_head cpu_timers[CPUCLOCK_MAX];
};
static inline void posix_cputimers_init(struct posix_cputimers *pct)
{
- memset(&pct->cputime_expires, 0, sizeof(pct->cputime_expires));
+ memset(&pct->expiries, 0, sizeof(pct->expiries));
INIT_LIST_HEAD(&pct->cpu_timers[0]);
INIT_LIST_HEAD(&pct->cpu_timers[1]);
INIT_LIST_HEAD(&pct->cpu_timers[2]);
@@ -96,7 +108,7 @@ void posix_cputimers_group_init(struct p
static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct,
u64 runtime)
{
- pct->cputime_expires.sched_exp = runtime;
+ pct->expiries[CPUCLOCK_SCHED] = runtime;
}
/* Init task static initializer */
--- a/include/linux/sched/types.h
+++ b/include/linux/sched/types.h
@@ -6,8 +6,8 @@
/**
* struct task_cputime - collected CPU time counts
- * @utime: time spent in user mode, in nanoseconds
* @stime: time spent in kernel mode, in nanoseconds
+ * @utime: time spent in user mode, in nanoseconds
* @sum_exec_runtime: total time spent on the CPU, in nanoseconds
*
* This structure groups together three kinds of CPU time that are tracked for
@@ -15,8 +15,8 @@
* these counts together and treat all three of them in parallel.
*/
struct task_cputime {
- u64 utime;
u64 stime;
+ u64 utime;
unsigned long long sum_exec_runtime;
};
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -18,13 +18,23 @@
#include "posix-timers.h"
+static inline void temporary_check(void)
+{
+ BUILD_BUG_ON(offsetof(struct task_cputime, stime) !=
+ CPUCLOCK_PROF * sizeof(u64));
+ BUILD_BUG_ON(offsetof(struct task_cputime, utime) !=
+ CPUCLOCK_VIRT * sizeof(u64));
+ BUILD_BUG_ON(offsetof(struct task_cputime, sum_exec_runtime) !=
+ CPUCLOCK_SCHED * sizeof(u64));
+}
+
static void posix_cpu_timer_rearm(struct k_itimer *timer);
void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit)
{
posix_cputimers_init(pct);
if (cpu_limit != RLIM_INFINITY)
- pct->cputime_expires.prof_exp = cpu_limit * NSEC_PER_SEC;
+ pct->expiries[CPUCLOCK_PROF] = cpu_limit * NSEC_PER_SEC;
}
/*
next prev parent reply other threads:[~2019-08-21 19:31 UTC|newest]
Thread overview: 137+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-21 19:08 [patch V2 00/38] posix-cpu-timers: Cleanup and consolidation Thomas Gleixner
2019-08-21 19:08 ` [patch V2 01/38] posix-cpu-timers: Provide task validation functions Thomas Gleixner
2019-08-21 22:33 ` Frederic Weisbecker
2019-08-21 23:03 ` Frederic Weisbecker
2019-08-23 15:33 ` Thomas Gleixner
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:08 ` [patch V2 02/38] posix-cpu-timers: Use common permission check in posix_cpu_clock_get() Thomas Gleixner
2019-08-21 23:40 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-29 11:00 ` kbuild test robot
2019-08-29 11:21 ` Thomas Gleixner
2019-08-30 1:08 ` [kbuild-all] " Philip Li
2019-08-29 11:23 ` kbuild test robot
2019-08-21 19:08 ` [patch V2 03/38] posix-cpu-timers: Use common permission check in posix_cpu_timer_create() Thomas Gleixner
2019-08-21 23:49 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:08 ` [patch V2 04/38] posix-cpu-timers: Provide quick sample function for itimer Thomas Gleixner
2019-08-22 12:13 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:08 ` [patch V2 05/38] itimers: Use quick sample function Thomas Gleixner
2019-08-22 12:15 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-29 23:47 ` kbuild test robot
2019-08-30 6:01 ` Thomas Gleixner
2019-08-21 19:08 ` [patch V2 06/38] posix-cpu-timers: Sample directly in timer check Thomas Gleixner
2019-08-22 12:30 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:08 ` [patch V2 07/38] posix-cpu-timers: Rename thread_group_cputimer() and make it static Thomas Gleixner
2019-08-22 12:41 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:08 ` [patch V2 08/38] posix-cpu-timers: Consolidate thread group sample code Thomas Gleixner
2019-08-22 13:49 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:08 ` [patch V2 09/38] posix-cpu-timers: Use clock ID in posix_cpu_timer_set() Thomas Gleixner
2019-08-22 13:58 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:08 ` [patch V2 10/38] posix-cpu-timers: Use clock ID in posix_cpu_timer_get() Thomas Gleixner
2019-08-22 14:07 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:08 ` [patch V2 11/38] posix-cpu-timers: Use clock ID in posix_cpu_timer_rearm() Thomas Gleixner
2019-08-22 14:12 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:08 ` [patch V2 12/38] posix-cpu-timers: Remove pointless return value check Thomas Gleixner
2019-08-22 14:15 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 13/38] posix-cpu-timers: Simplify sample functions Thomas Gleixner
2019-08-22 14:20 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 14/38] posix-cpu-timers: Get rid of pointer indirection Thomas Gleixner
2019-08-22 14:41 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 15/38] posix-cpu-timers: Sample task times once in expiry check Thomas Gleixner
2019-08-22 15:00 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 16/38] posix-cpu-timers: Move prof/virt_ticks into caller Thomas Gleixner
2019-08-22 15:05 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 17/38] posix-cpu-timers: Create a container struct Thomas Gleixner
2019-08-22 15:32 ` Frederic Weisbecker
2019-08-23 15:34 ` Thomas Gleixner
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 19/38] posix-cpu-timers: Move expiry cache into struct posix_cputimers Thomas Gleixner
2019-08-22 16:29 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` Thomas Gleixner [this message]
2019-08-23 17:33 ` [patch V2 20/38] posix-cpu-timers: Provide array based access to expiry cache Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 21/38] posix-cpu-timers: Simplify timer queueing Thomas Gleixner
2019-08-23 17:51 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 22/38] posix-cpu-timers: Simplify set_process_cpu_timer() Thomas Gleixner
2019-08-23 18:00 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 23/38] posix-cpu-timers: Switch check_*_timers() to array cache Thomas Gleixner
2019-08-23 18:13 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 24/38] posix-cpu-timers: Remove the odd field rename defines Thomas Gleixner
2019-08-23 18:36 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 25/38] posix-cpu-timers: Provide array based sample functions Thomas Gleixner
2019-08-23 22:08 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 26/38] posix-cpu-timers: Make expiry checks array based Thomas Gleixner
2019-08-23 22:44 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 27/38] posix-cpu-timers: Remove cputime_expires Thomas Gleixner
2019-08-23 22:50 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 28/38] posix-cpu-timers: Restructure expiry array Thomas Gleixner
2019-08-26 16:32 ` Frederic Weisbecker
2019-08-26 18:16 ` Thomas Gleixner
2019-08-26 18:22 ` [patch V3 " Thomas Gleixner
2019-08-26 19:45 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-26 21:06 ` [patch V2 28/38] " Frederic Weisbecker
2019-08-26 21:46 ` Thomas Gleixner
2019-08-21 19:09 ` [patch V2 29/38] posix-cpu-timers: Switch thread group sampling to array Thomas Gleixner
2019-08-26 21:12 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 30/38] posix-cpu-timers: Respect INFINITY for hard RTTIME limit Thomas Gleixner
2019-08-26 21:19 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 31/38] rlimit: Rewrite non-sensical RLIMIT_CPU comment Thomas Gleixner
2019-08-26 21:41 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 32/38] posix-cpu-timers: Get rid of zero checks Thomas Gleixner
2019-08-26 21:57 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 33/38] posix-cpu-timers: Consolidate timer expiry further Thomas Gleixner
2019-08-26 22:29 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 34/38] posix-cpu-timers: Get rid of 64bit divisions Thomas Gleixner
2019-08-26 22:51 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 35/38] posix-cpu-timers: Remove pointless comparisons Thomas Gleixner
2019-08-26 22:59 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 36/38] posix-cpu-timers: Deduplicate rlimit handling Thomas Gleixner
2019-08-26 23:13 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 37/38] posix-cpu-timers: Move state tracking to struct posix_cputimers Thomas Gleixner
2019-08-26 23:28 ` Frederic Weisbecker
2019-08-26 23:33 ` Thomas Gleixner
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-21 19:09 ` [patch V2 38/38] posix-cpu-timers: Utilize timerqueue for storage Thomas Gleixner
2019-08-27 0:48 ` Frederic Weisbecker
2019-08-27 6:08 ` Thomas Gleixner
2019-08-27 13:17 ` Frederic Weisbecker
2019-08-27 13:46 ` Thomas Gleixner
2019-08-27 19:31 ` [patch V3 " Thomas Gleixner
2019-08-27 22:23 ` Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-08-22 0:54 ` [patch V2 00/38] posix-cpu-timers: Cleanup and consolidation Christoph Hellwig
2019-08-22 1:02 ` Frederic Weisbecker
2019-08-22 1:02 ` Christoph Hellwig
[not found] ` <20190821192920.909530418@linutronix.de>
2019-08-22 16:06 ` [patch V2 18/38] sched: Move struct task_cputime to types.h Frederic Weisbecker
2019-08-28 10:16 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
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