diff options
| author | Frederic Weisbecker <frederic@kernel.org> | 2024-02-25 23:55:04 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2024-02-26 11:37:32 +0100 |
| commit | a478ffb2ae234ee1ece2b84719762c54d304e2c7 (patch) | |
| tree | 65f1f3803cdd17c4d1b4c4be3b8269fd4a35d490 /kernel/time/tick-sched.h | |
| parent | 3ce74f1a8566dbbc9774f85fb0ce781fe290fd32 (diff) | |
| download | linux-a478ffb2ae234ee1ece2b84719762c54d304e2c7.tar.gz | |
tick: Move individual bit features to debuggable mask accesses
The individual bitfields of struct tick_sched must be modified from
IRQs disabled places, otherwise local modifications can race due to them
sharing the same memory storage.
The recent move of the "got_idle_tick" bitfield to its own storage shows
that the use of these bitfields, as pretty as they look, can be as much
error prone.
In order to avoid future issues of the like and make sure that those
bitfields are safely accessed, move those flags to an explicit mask
along with a mutator function performing the basic IRQs disabled sanity
check.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240225225508.11587-13-frederic@kernel.org
Diffstat (limited to 'kernel/time/tick-sched.h')
| -rw-r--r-- | kernel/time/tick-sched.h | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h index 3b555e0fa93783..07a4c0144c47ff 100644 --- a/kernel/time/tick-sched.h +++ b/kernel/time/tick-sched.h @@ -20,14 +20,22 @@ enum tick_nohz_mode { NOHZ_MODE_HIGHRES, }; +/* The CPU is in the tick idle mode */ +#define TS_FLAG_INIDLE BIT(0) +/* The idle tick has been stopped */ +#define TS_FLAG_STOPPED BIT(1) +/* + * Indicator that the CPU is actively in the tick idle mode; + * it is reset during irq handling phases. + */ +#define TS_FLAG_IDLE_ACTIVE BIT(2) +/* CPU was the last one doing do_timer before going idle */ +#define TS_FLAG_DO_TIMER_LAST BIT(3) + /** * struct tick_sched - sched tick emulation and no idle tick control/stats * - * @inidle: Indicator that the CPU is in the tick idle mode - * @tick_stopped: Indicator that the idle tick has been stopped - * @idle_active: Indicator that the CPU is actively in the tick idle mode; - * it is reset during irq handling phases. - * @do_timer_last: CPU was the last one doing do_timer before going idle + * @flags: State flags gathering the TS_FLAG_* features * @got_idle_tick: Tick timer function has run with @inidle set * @stalled_jiffies: Number of stalled jiffies detected across ticks * @last_tick_jiffies: Value of jiffies seen on last tick @@ -57,10 +65,7 @@ enum tick_nohz_mode { */ struct tick_sched { /* Common flags */ - unsigned int inidle : 1; - unsigned int tick_stopped : 1; - unsigned int idle_active : 1; - unsigned int do_timer_last : 1; + unsigned long flags; /* Tick handling: jiffies stall check */ unsigned int stalled_jiffies; |