* [PATCH v3 0/3] time: some cleanup for jiffies and alarmtimer
@ 2025-04-30 3:27 Su Hui
2025-04-30 3:27 ` [PATCH v3 1/3] time/jiffies: change register_refined_jiffies() to void __init Su Hui
` (2 more replies)
0 siblings, 3 replies; 10+ messages in thread
From: Su Hui @ 2025-04-30 3:27 UTC (permalink / raw)
To: jstultz, tglx, sboyd
Cc: Su Hui, eahariha, luiz.von.dentz, anna-maria, ojeda,
linux-kernel, kernel-janitors
There are some small cleanup for jiffies.c and alarmtimer.c.
Compile test only.
v3:
- add a WARN_ON_ONCE in patch 2.
v2:
- remove some guard() useages in patch 3.
- https://lore.kernel.org/all/20250427113529.1473800-1-suhui@nfschina.com/
v1:
- https://lore.kernel.org/all/20250424144819.24884-1-suhui@nfschina.com/
Su Hui (3):
time/jiffies: change register_refined_jiffies() to void __init
alarmtimer: remove dead return value in clock2alarm()
alarmtimer: switch some spin_{lock,unlock}_irqsave() to guard()
include/linux/jiffies.h | 2 +-
kernel/time/alarmtimer.c | 62 +++++++++++++++++-----------------------
kernel/time/jiffies.c | 5 +---
3 files changed, 28 insertions(+), 41 deletions(-)
--
2.30.2
^ permalink raw reply [flat|nested] 10+ messages in thread* [PATCH v3 1/3] time/jiffies: change register_refined_jiffies() to void __init 2025-04-30 3:27 [PATCH v3 0/3] time: some cleanup for jiffies and alarmtimer Su Hui @ 2025-04-30 3:27 ` Su Hui 2025-04-30 7:22 ` [tip: timers/core] time/jiffies: Change " tip-bot2 for Su Hui 2025-04-30 3:27 ` [PATCH v3 2/3] alarmtimer: remove dead return value in clock2alarm() Su Hui 2025-04-30 3:27 ` [PATCH v3 3/3] alarmtimer: switch some spin_{lock,unlock}_irqsave() to guard() Su Hui 2 siblings, 1 reply; 10+ messages in thread From: Su Hui @ 2025-04-30 3:27 UTC (permalink / raw) To: jstultz Cc: Su Hui, tglx, eahariha, geert, anna-maria, ojeda, linux-kernel, kernel-janitors register_refined_jiffies() is only used in setup code and always return 0. Mark it to __init to save some bytes and change it to void. Signed-off-by: Su Hui <suhui@nfschina.com> --- v2/v3: - No change. include/linux/jiffies.h | 2 +- kernel/time/jiffies.c | 5 +---- 2 files changed, 2 insertions(+), 5 deletions(-) diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h index 0ea8c9887429..91b20788273d 100644 --- a/include/linux/jiffies.h +++ b/include/linux/jiffies.h @@ -59,7 +59,7 @@ /* LATCH is used in the interval timer and ftape setup. */ #define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */ -extern int register_refined_jiffies(long clock_tick_rate); +extern void register_refined_jiffies(long clock_tick_rate); /* TICK_USEC is the time between ticks in usec assuming SHIFTED_HZ */ #define TICK_USEC ((USEC_PER_SEC + HZ/2) / HZ) diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c index bc4db9e5ab70..34eeacac2253 100644 --- a/kernel/time/jiffies.c +++ b/kernel/time/jiffies.c @@ -75,13 +75,11 @@ struct clocksource * __init __weak clocksource_default_clock(void) static struct clocksource refined_jiffies; -int register_refined_jiffies(long cycles_per_second) +void __init register_refined_jiffies(long cycles_per_second) { u64 nsec_per_tick, shift_hz; long cycles_per_tick; - - refined_jiffies = clocksource_jiffies; refined_jiffies.name = "refined-jiffies"; refined_jiffies.rating++; @@ -100,5 +98,4 @@ int register_refined_jiffies(long cycles_per_second) refined_jiffies.mult = ((u32)nsec_per_tick) << JIFFIES_SHIFT; __clocksource_register(&refined_jiffies); - return 0; } -- 2.30.2 ^ permalink raw reply [flat|nested] 10+ messages in thread
* [tip: timers/core] time/jiffies: Change register_refined_jiffies() to void __init 2025-04-30 3:27 ` [PATCH v3 1/3] time/jiffies: change register_refined_jiffies() to void __init Su Hui @ 2025-04-30 7:22 ` tip-bot2 for Su Hui 0 siblings, 0 replies; 10+ messages in thread From: tip-bot2 for Su Hui @ 2025-04-30 7:22 UTC (permalink / raw) To: linux-tip-commits; +Cc: Su Hui, Thomas Gleixner, x86, linux-kernel The following commit has been merged into the timers/core branch of tip: Commit-ID: 007c07168ac0c64387be500f6604b09ace3f3bdc Gitweb: https://git.kernel.org/tip/007c07168ac0c64387be500f6604b09ace3f3bdc Author: Su Hui <suhui@nfschina.com> AuthorDate: Wed, 30 Apr 2025 11:27:32 +08:00 Committer: Thomas Gleixner <tglx@linutronix.de> CommitterDate: Wed, 30 Apr 2025 09:06:23 +02:00 time/jiffies: Change register_refined_jiffies() to void __init register_refined_jiffies() is only used in setup code and always returns 0. Mark it as __init to save some bytes and change it to void. Signed-off-by: Su Hui <suhui@nfschina.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250430032734.2079290-2-suhui@nfschina.com --- include/linux/jiffies.h | 2 +- kernel/time/jiffies.c | 5 +---- 2 files changed, 2 insertions(+), 5 deletions(-) diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h index 0ea8c98..91b2078 100644 --- a/include/linux/jiffies.h +++ b/include/linux/jiffies.h @@ -59,7 +59,7 @@ /* LATCH is used in the interval timer and ftape setup. */ #define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */ -extern int register_refined_jiffies(long clock_tick_rate); +extern void register_refined_jiffies(long clock_tick_rate); /* TICK_USEC is the time between ticks in usec assuming SHIFTED_HZ */ #define TICK_USEC ((USEC_PER_SEC + HZ/2) / HZ) diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c index bc4db9e..34eeaca 100644 --- a/kernel/time/jiffies.c +++ b/kernel/time/jiffies.c @@ -75,13 +75,11 @@ struct clocksource * __init __weak clocksource_default_clock(void) static struct clocksource refined_jiffies; -int register_refined_jiffies(long cycles_per_second) +void __init register_refined_jiffies(long cycles_per_second) { u64 nsec_per_tick, shift_hz; long cycles_per_tick; - - refined_jiffies = clocksource_jiffies; refined_jiffies.name = "refined-jiffies"; refined_jiffies.rating++; @@ -100,5 +98,4 @@ int register_refined_jiffies(long cycles_per_second) refined_jiffies.mult = ((u32)nsec_per_tick) << JIFFIES_SHIFT; __clocksource_register(&refined_jiffies); - return 0; } ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v3 2/3] alarmtimer: remove dead return value in clock2alarm() 2025-04-30 3:27 [PATCH v3 0/3] time: some cleanup for jiffies and alarmtimer Su Hui 2025-04-30 3:27 ` [PATCH v3 1/3] time/jiffies: change register_refined_jiffies() to void __init Su Hui @ 2025-04-30 3:27 ` Su Hui 2025-04-30 7:22 ` [tip: timers/core] alarmtimer: Remove " tip-bot2 for Su Hui 2025-04-30 22:14 ` [PATCH v3 2/3] alarmtimer: remove " John Stultz 2025-04-30 3:27 ` [PATCH v3 3/3] alarmtimer: switch some spin_{lock,unlock}_irqsave() to guard() Su Hui 2 siblings, 2 replies; 10+ messages in thread From: Su Hui @ 2025-04-30 3:27 UTC (permalink / raw) To: jstultz, tglx, sboyd; +Cc: Su Hui, linux-kernel, kernel-janitors 'clockid' only can be ALARM_REALTIME and ALARM_BOOTTIME. It's impossible to return -1 and callers never check the value of -1. Only alarm_clock_get_timespec(), alarm_clock_get_ktime(), alarm_timer_create() and alarm_timer_nsleep() call clock2alarm(). These callers using clockid_to_kclock() to get 'struct k_clock', this ensures clock2alarm() never returns -1. Remove the impossible -1 return value, and add a warn to be aware of any misuse of this function. Signed-off-by: Su Hui <suhui@nfschina.com> --- v3: - Add WARN_ON_ONCE to notice any misuse of this function. v2: - No Change. kernel/time/alarmtimer.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 0ddccdff119a..621d39666e29 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -515,9 +515,9 @@ static enum alarmtimer_type clock2alarm(clockid_t clockid) { if (clockid == CLOCK_REALTIME_ALARM) return ALARM_REALTIME; - if (clockid == CLOCK_BOOTTIME_ALARM) - return ALARM_BOOTTIME; - return -1; + + WARN_ON_ONCE(clockid != CLOCK_BOOTTIME_ALARM); + return ALARM_BOOTTIME; } /** -- 2.30.2 ^ permalink raw reply [flat|nested] 10+ messages in thread
* [tip: timers/core] alarmtimer: Remove dead return value in clock2alarm() 2025-04-30 3:27 ` [PATCH v3 2/3] alarmtimer: remove dead return value in clock2alarm() Su Hui @ 2025-04-30 7:22 ` tip-bot2 for Su Hui 2025-04-30 22:14 ` [PATCH v3 2/3] alarmtimer: remove " John Stultz 1 sibling, 0 replies; 10+ messages in thread From: tip-bot2 for Su Hui @ 2025-04-30 7:22 UTC (permalink / raw) To: linux-tip-commits; +Cc: Su Hui, Thomas Gleixner, x86, linux-kernel The following commit has been merged into the timers/core branch of tip: Commit-ID: d8ca84d48a2a2d4f6780980743c34b70c49f5844 Gitweb: https://git.kernel.org/tip/d8ca84d48a2a2d4f6780980743c34b70c49f5844 Author: Su Hui <suhui@nfschina.com> AuthorDate: Wed, 30 Apr 2025 11:27:33 +08:00 Committer: Thomas Gleixner <tglx@linutronix.de> CommitterDate: Wed, 30 Apr 2025 09:06:23 +02:00 alarmtimer: Remove dead return value in clock2alarm() 'clockid' can only be ALARM_REALTIME and ALARM_BOOTTIME. It's impossible to return -1 and callers never check the return value. Only alarm_clock_get_timespec(), alarm_clock_get_ktime(), alarm_timer_create() and alarm_timer_nsleep() call clock2alarm(). These callers use clockid_to_kclock() to get 'struct k_clock', which ensures that clock2alarm() never returns -1. Remove the impossible -1 return value, and add a warning to notify about any future misuse of this function. Signed-off-by: Su Hui <suhui@nfschina.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250430032734.2079290-3-suhui@nfschina.com --- kernel/time/alarmtimer.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 0ddccdf..621d396 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -515,9 +515,9 @@ static enum alarmtimer_type clock2alarm(clockid_t clockid) { if (clockid == CLOCK_REALTIME_ALARM) return ALARM_REALTIME; - if (clockid == CLOCK_BOOTTIME_ALARM) - return ALARM_BOOTTIME; - return -1; + + WARN_ON_ONCE(clockid != CLOCK_BOOTTIME_ALARM); + return ALARM_BOOTTIME; } /** ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v3 2/3] alarmtimer: remove dead return value in clock2alarm() 2025-04-30 3:27 ` [PATCH v3 2/3] alarmtimer: remove dead return value in clock2alarm() Su Hui 2025-04-30 7:22 ` [tip: timers/core] alarmtimer: Remove " tip-bot2 for Su Hui @ 2025-04-30 22:14 ` John Stultz 1 sibling, 0 replies; 10+ messages in thread From: John Stultz @ 2025-04-30 22:14 UTC (permalink / raw) To: Su Hui; +Cc: tglx, sboyd, linux-kernel, kernel-janitors On Tue, Apr 29, 2025 at 8:27 PM Su Hui <suhui@nfschina.com> wrote: > > 'clockid' only can be ALARM_REALTIME and ALARM_BOOTTIME. It's impossible > to return -1 and callers never check the value of -1. > > Only alarm_clock_get_timespec(), alarm_clock_get_ktime(), > alarm_timer_create() and alarm_timer_nsleep() call clock2alarm(). These > callers using clockid_to_kclock() to get 'struct k_clock', this ensures > clock2alarm() never returns -1. > > Remove the impossible -1 return value, and add a warn to be aware of any > misuse of this function. > > Signed-off-by: Su Hui <suhui@nfschina.com> Acked-by: John Stultz <jstultz@google.com> ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v3 3/3] alarmtimer: switch some spin_{lock,unlock}_irqsave() to guard() 2025-04-30 3:27 [PATCH v3 0/3] time: some cleanup for jiffies and alarmtimer Su Hui 2025-04-30 3:27 ` [PATCH v3 1/3] time/jiffies: change register_refined_jiffies() to void __init Su Hui 2025-04-30 3:27 ` [PATCH v3 2/3] alarmtimer: remove dead return value in clock2alarm() Su Hui @ 2025-04-30 3:27 ` Su Hui 2025-04-30 7:04 ` Thomas Gleixner 2025-04-30 7:22 ` [tip: timers/core] alarmtimer: Switch spin_{lock,unlock}_irqsave() to guards tip-bot2 for Su Hui 2 siblings, 2 replies; 10+ messages in thread From: Su Hui @ 2025-04-30 3:27 UTC (permalink / raw) To: jstultz, tglx, sboyd; +Cc: Su Hui, dan.carpenter, linux-kernel, kernel-janitors Using guard/scoped_guard() to simplify code. Using guard() to remove 'goto unlock' label is neater especially. Signed-off-by: Su Hui <suhui@nfschina.com> Acked-by: John Stultz <jstultz@google.com> --- v3: - No Change. v2: - Remove some guard() usages acrodding to john's suggestions. kernel/time/alarmtimer.c | 56 +++++++++++++++++----------------------- 1 file changed, 23 insertions(+), 33 deletions(-) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 621d39666e29..9f75aaf1ba35 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -70,12 +70,10 @@ static DEFINE_SPINLOCK(rtcdev_lock); */ struct rtc_device *alarmtimer_get_rtcdev(void) { - unsigned long flags; struct rtc_device *ret; - spin_lock_irqsave(&rtcdev_lock, flags); + guard(spinlock_irqsave)(&rtcdev_lock); ret = rtcdev; - spin_unlock_irqrestore(&rtcdev_lock, flags); return ret; } @@ -83,7 +81,6 @@ EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev); static int alarmtimer_rtc_add_device(struct device *dev) { - unsigned long flags; struct rtc_device *rtc = to_rtc_device(dev); struct platform_device *pdev; int ret = 0; @@ -101,22 +98,21 @@ static int alarmtimer_rtc_add_device(struct device *dev) if (!IS_ERR(pdev)) device_init_wakeup(&pdev->dev, true); - spin_lock_irqsave(&rtcdev_lock, flags); - if (!IS_ERR(pdev) && !rtcdev) { - if (!try_module_get(rtc->owner)) { + scoped_guard(spinlock_irqsave, &rtcdev_lock) { + if (!IS_ERR(pdev) && !rtcdev) { + if (!try_module_get(rtc->owner)) { + ret = -1; + break; + } + + rtcdev = rtc; + /* hold a reference so it doesn't go away */ + get_device(dev); + pdev = NULL; + } else { ret = -1; - goto unlock; } - - rtcdev = rtc; - /* hold a reference so it doesn't go away */ - get_device(dev); - pdev = NULL; - } else { - ret = -1; } -unlock: - spin_unlock_irqrestore(&rtcdev_lock, flags); platform_device_unregister(pdev); @@ -198,7 +194,7 @@ static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) struct alarm *alarm = container_of(timer, struct alarm, timer); struct alarm_base *base = &alarm_bases[alarm->type]; - scoped_guard (spinlock_irqsave, &base->lock) + scoped_guard(spinlock_irqsave, &base->lock) alarmtimer_dequeue(base, alarm); if (alarm->function) @@ -251,9 +247,8 @@ static int alarmtimer_suspend(struct device *dev) struct timerqueue_node *next; ktime_t delta; - spin_lock_irqsave(&base->lock, flags); - next = timerqueue_getnext(&base->timerqueue); - spin_unlock_irqrestore(&base->lock, flags); + scoped_guard(spinlock_irqsave, &base->lock) + next = timerqueue_getnext(&base->timerqueue); if (!next) continue; delta = ktime_sub(next->expires, base->get_ktime()); @@ -381,13 +376,11 @@ EXPORT_SYMBOL_GPL(alarm_start_relative); void alarm_restart(struct alarm *alarm) { struct alarm_base *base = &alarm_bases[alarm->type]; - unsigned long flags; - spin_lock_irqsave(&base->lock, flags); + guard(spinlock_irqsave)(&base->lock); hrtimer_set_expires(&alarm->timer, alarm->node.expires); hrtimer_restart(&alarm->timer); alarmtimer_enqueue(base, alarm); - spin_unlock_irqrestore(&base->lock, flags); } EXPORT_SYMBOL_GPL(alarm_restart); @@ -401,14 +394,13 @@ EXPORT_SYMBOL_GPL(alarm_restart); int alarm_try_to_cancel(struct alarm *alarm) { struct alarm_base *base = &alarm_bases[alarm->type]; - unsigned long flags; int ret; - spin_lock_irqsave(&base->lock, flags); - ret = hrtimer_try_to_cancel(&alarm->timer); - if (ret >= 0) - alarmtimer_dequeue(base, alarm); - spin_unlock_irqrestore(&base->lock, flags); + scoped_guard(spinlock_irqsave, &base->lock) { + ret = hrtimer_try_to_cancel(&alarm->timer); + if (ret >= 0) + alarmtimer_dequeue(base, alarm); + } trace_alarmtimer_cancel(alarm, base->get_ktime()); return ret; @@ -479,7 +471,6 @@ EXPORT_SYMBOL_GPL(alarm_forward_now); static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) { struct alarm_base *base; - unsigned long flags; ktime_t delta; switch(type) { @@ -498,13 +489,12 @@ static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) delta = ktime_sub(absexp, base->get_ktime()); - spin_lock_irqsave(&freezer_delta_lock, flags); + guard(spinlock_irqsave)(&freezer_delta_lock); if (!freezer_delta || (delta < freezer_delta)) { freezer_delta = delta; freezer_expires = absexp; freezer_alarmtype = type; } - spin_unlock_irqrestore(&freezer_delta_lock, flags); } /** -- 2.30.2 ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v3 3/3] alarmtimer: switch some spin_{lock,unlock}_irqsave() to guard() 2025-04-30 3:27 ` [PATCH v3 3/3] alarmtimer: switch some spin_{lock,unlock}_irqsave() to guard() Su Hui @ 2025-04-30 7:04 ` Thomas Gleixner 2025-04-30 7:19 ` Su Hui 2025-04-30 7:22 ` [tip: timers/core] alarmtimer: Switch spin_{lock,unlock}_irqsave() to guards tip-bot2 for Su Hui 1 sibling, 1 reply; 10+ messages in thread From: Thomas Gleixner @ 2025-04-30 7:04 UTC (permalink / raw) To: Su Hui, jstultz, sboyd Cc: Su Hui, dan.carpenter, linux-kernel, kernel-janitors On Wed, Apr 30 2025 at 11:27, Su Hui wrote: > - spin_lock_irqsave(&rtcdev_lock, flags); > - if (!IS_ERR(pdev) && !rtcdev) { > - if (!try_module_get(rtc->owner)) { > + scoped_guard(spinlock_irqsave, &rtcdev_lock) { > + if (!IS_ERR(pdev) && !rtcdev) { > + if (!try_module_get(rtc->owner)) { > + ret = -1; > + break; This really reads odd and relies on the internals of scoped_guard(). I actually had to look at the scoped_guard() implementation to validate it. The whole thing can be simplified to: scoped_guard(spinlock_irqsave, &rtcdev_lock) { if (!IS_ERR(pdev) && !rtcdev && try_module_get(rtc->owner)) { rtcdev = rtc; /* hold a reference so it doesn't go away */ get_device(dev); pdev = NULL; } else { ret = -1; } No? No need to resend. I fixed it up already. Thanks, tglx ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v3 3/3] alarmtimer: switch some spin_{lock,unlock}_irqsave() to guard() 2025-04-30 7:04 ` Thomas Gleixner @ 2025-04-30 7:19 ` Su Hui 0 siblings, 0 replies; 10+ messages in thread From: Su Hui @ 2025-04-30 7:19 UTC (permalink / raw) To: Thomas Gleixner, jstultz, sboyd Cc: dan.carpenter, linux-kernel, kernel-janitors On 2025/4/30 15:04, Thomas Gleixner wrote: > On Wed, Apr 30 2025 at 11:27, Su Hui wrote: >> - spin_lock_irqsave(&rtcdev_lock, flags); >> - if (!IS_ERR(pdev) && !rtcdev) { >> - if (!try_module_get(rtc->owner)) { >> + scoped_guard(spinlock_irqsave, &rtcdev_lock) { >> + if (!IS_ERR(pdev) && !rtcdev) { >> + if (!try_module_get(rtc->owner)) { >> + ret = -1; >> + break; > This really reads odd and relies on the internals of scoped_guard(). I > actually had to look at the scoped_guard() implementation to validate > it. > > The whole thing can be simplified to: > > scoped_guard(spinlock_irqsave, &rtcdev_lock) { > if (!IS_ERR(pdev) && !rtcdev && try_module_get(rtc->owner)) { > rtcdev = rtc; > /* hold a reference so it doesn't go away */ > get_device(dev); > pdev = NULL; > } else { > ret = -1; > } > > No? Yes, it's simpler and better. > No need to resend. I fixed it up already. Thanks a lot :). Su Hui ^ permalink raw reply [flat|nested] 10+ messages in thread
* [tip: timers/core] alarmtimer: Switch spin_{lock,unlock}_irqsave() to guards 2025-04-30 3:27 ` [PATCH v3 3/3] alarmtimer: switch some spin_{lock,unlock}_irqsave() to guard() Su Hui 2025-04-30 7:04 ` Thomas Gleixner @ 2025-04-30 7:22 ` tip-bot2 for Su Hui 1 sibling, 0 replies; 10+ messages in thread From: tip-bot2 for Su Hui @ 2025-04-30 7:22 UTC (permalink / raw) To: linux-tip-commits; +Cc: Su Hui, Thomas Gleixner, John Stultz, x86, linux-kernel The following commit has been merged into the timers/core branch of tip: Commit-ID: 2117c1d503b4e0fd0c6776ae9fe4df2260643eae Gitweb: https://git.kernel.org/tip/2117c1d503b4e0fd0c6776ae9fe4df2260643eae Author: Su Hui <suhui@nfschina.com> AuthorDate: Wed, 30 Apr 2025 11:27:34 +08:00 Committer: Thomas Gleixner <tglx@linutronix.de> CommitterDate: Wed, 30 Apr 2025 09:06:23 +02:00 alarmtimer: Switch spin_{lock,unlock}_irqsave() to guards Using guard/scoped_guard() to simplify code. Using guard() to remove 'goto unlock' label is neater especially. [ tglx: Brought back the scoped_guard()'s which were dropped in v2 and simplified alarmtimer_rtc_add_device() ] Signed-off-by: Su Hui <suhui@nfschina.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <jstultz@google.com> Link: https://lore.kernel.org/all/20250430032734.2079290-4-suhui@nfschina.com --- kernel/time/alarmtimer.c | 78 +++++++++++++++------------------------ 1 file changed, 30 insertions(+), 48 deletions(-) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 621d396..577f0e6 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -70,12 +70,10 @@ static DEFINE_SPINLOCK(rtcdev_lock); */ struct rtc_device *alarmtimer_get_rtcdev(void) { - unsigned long flags; struct rtc_device *ret; - spin_lock_irqsave(&rtcdev_lock, flags); + guard(spinlock_irqsave)(&rtcdev_lock); ret = rtcdev; - spin_unlock_irqrestore(&rtcdev_lock, flags); return ret; } @@ -83,7 +81,6 @@ EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev); static int alarmtimer_rtc_add_device(struct device *dev) { - unsigned long flags; struct rtc_device *rtc = to_rtc_device(dev); struct platform_device *pdev; int ret = 0; @@ -101,25 +98,18 @@ static int alarmtimer_rtc_add_device(struct device *dev) if (!IS_ERR(pdev)) device_init_wakeup(&pdev->dev, true); - spin_lock_irqsave(&rtcdev_lock, flags); - if (!IS_ERR(pdev) && !rtcdev) { - if (!try_module_get(rtc->owner)) { + scoped_guard(spinlock_irqsave, &rtcdev_lock) { + if (!IS_ERR(pdev) && !rtcdev && try_module_get(rtc->owner)) { + rtcdev = rtc; + /* hold a reference so it doesn't go away */ + get_device(dev); + pdev = NULL; + } else { ret = -1; - goto unlock; } - - rtcdev = rtc; - /* hold a reference so it doesn't go away */ - get_device(dev); - pdev = NULL; - } else { - ret = -1; } -unlock: - spin_unlock_irqrestore(&rtcdev_lock, flags); platform_device_unregister(pdev); - return ret; } @@ -198,7 +188,7 @@ static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) struct alarm *alarm = container_of(timer, struct alarm, timer); struct alarm_base *base = &alarm_bases[alarm->type]; - scoped_guard (spinlock_irqsave, &base->lock) + scoped_guard(spinlock_irqsave, &base->lock) alarmtimer_dequeue(base, alarm); if (alarm->function) @@ -228,17 +218,16 @@ EXPORT_SYMBOL_GPL(alarm_expires_remaining); static int alarmtimer_suspend(struct device *dev) { ktime_t min, now, expires; - int i, ret, type; struct rtc_device *rtc; - unsigned long flags; struct rtc_time tm; + int i, ret, type; - spin_lock_irqsave(&freezer_delta_lock, flags); - min = freezer_delta; - expires = freezer_expires; - type = freezer_alarmtype; - freezer_delta = 0; - spin_unlock_irqrestore(&freezer_delta_lock, flags); + scoped_guard(spinlock_irqsave, &freezer_delta_lock) { + min = freezer_delta; + expires = freezer_expires; + type = freezer_alarmtype; + freezer_delta = 0; + } rtc = alarmtimer_get_rtcdev(); /* If we have no rtcdev, just return */ @@ -251,9 +240,8 @@ static int alarmtimer_suspend(struct device *dev) struct timerqueue_node *next; ktime_t delta; - spin_lock_irqsave(&base->lock, flags); - next = timerqueue_getnext(&base->timerqueue); - spin_unlock_irqrestore(&base->lock, flags); + scoped_guard(spinlock_irqsave, &base->lock) + next = timerqueue_getnext(&base->timerqueue); if (!next) continue; delta = ktime_sub(next->expires, base->get_ktime()); @@ -352,13 +340,12 @@ EXPORT_SYMBOL_GPL(alarm_init); void alarm_start(struct alarm *alarm, ktime_t start) { struct alarm_base *base = &alarm_bases[alarm->type]; - unsigned long flags; - spin_lock_irqsave(&base->lock, flags); - alarm->node.expires = start; - alarmtimer_enqueue(base, alarm); - hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS); - spin_unlock_irqrestore(&base->lock, flags); + scoped_guard(spinlock_irqsave, &base->lock) { + alarm->node.expires = start; + alarmtimer_enqueue(base, alarm); + hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS); + } trace_alarmtimer_start(alarm, base->get_ktime()); } @@ -381,13 +368,11 @@ EXPORT_SYMBOL_GPL(alarm_start_relative); void alarm_restart(struct alarm *alarm) { struct alarm_base *base = &alarm_bases[alarm->type]; - unsigned long flags; - spin_lock_irqsave(&base->lock, flags); + guard(spinlock_irqsave)(&base->lock); hrtimer_set_expires(&alarm->timer, alarm->node.expires); hrtimer_restart(&alarm->timer); alarmtimer_enqueue(base, alarm); - spin_unlock_irqrestore(&base->lock, flags); } EXPORT_SYMBOL_GPL(alarm_restart); @@ -401,14 +386,13 @@ EXPORT_SYMBOL_GPL(alarm_restart); int alarm_try_to_cancel(struct alarm *alarm) { struct alarm_base *base = &alarm_bases[alarm->type]; - unsigned long flags; int ret; - spin_lock_irqsave(&base->lock, flags); - ret = hrtimer_try_to_cancel(&alarm->timer); - if (ret >= 0) - alarmtimer_dequeue(base, alarm); - spin_unlock_irqrestore(&base->lock, flags); + scoped_guard(spinlock_irqsave, &base->lock) { + ret = hrtimer_try_to_cancel(&alarm->timer); + if (ret >= 0) + alarmtimer_dequeue(base, alarm); + } trace_alarmtimer_cancel(alarm, base->get_ktime()); return ret; @@ -479,7 +463,6 @@ EXPORT_SYMBOL_GPL(alarm_forward_now); static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) { struct alarm_base *base; - unsigned long flags; ktime_t delta; switch(type) { @@ -498,13 +481,12 @@ static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) delta = ktime_sub(absexp, base->get_ktime()); - spin_lock_irqsave(&freezer_delta_lock, flags); + guard(spinlock_irqsave)(&freezer_delta_lock); if (!freezer_delta || (delta < freezer_delta)) { freezer_delta = delta; freezer_expires = absexp; freezer_alarmtype = type; } - spin_unlock_irqrestore(&freezer_delta_lock, flags); } /** ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2025-04-30 22:14 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
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2025-04-30 3:27 [PATCH v3 0/3] time: some cleanup for jiffies and alarmtimer Su Hui
2025-04-30 3:27 ` [PATCH v3 1/3] time/jiffies: change register_refined_jiffies() to void __init Su Hui
2025-04-30 7:22 ` [tip: timers/core] time/jiffies: Change " tip-bot2 for Su Hui
2025-04-30 3:27 ` [PATCH v3 2/3] alarmtimer: remove dead return value in clock2alarm() Su Hui
2025-04-30 7:22 ` [tip: timers/core] alarmtimer: Remove " tip-bot2 for Su Hui
2025-04-30 22:14 ` [PATCH v3 2/3] alarmtimer: remove " John Stultz
2025-04-30 3:27 ` [PATCH v3 3/3] alarmtimer: switch some spin_{lock,unlock}_irqsave() to guard() Su Hui
2025-04-30 7:04 ` Thomas Gleixner
2025-04-30 7:19 ` Su Hui
2025-04-30 7:22 ` [tip: timers/core] alarmtimer: Switch spin_{lock,unlock}_irqsave() to guards tip-bot2 for Su Hui
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