* [PATCH] irq_work: Improve CPU Responsiveness in irq_work_sync with cond_resched()
@ 2024-09-18 15:23 Steven Davis
2024-09-19 13:54 ` Thomas Gleixner
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Steven Davis @ 2024-09-18 15:23 UTC (permalink / raw)
To: akpm; +Cc: linux-kernel, Steven Davis
Add cond_resched() to the busy-wait loop in irq_work_sync to improve
CPU responsiveness and prevent starvation of other tasks.
Previously, the busy-wait loop used cpu_relax() alone, which, while
reducing power consumption, could still lead to excessive CPU
monopolization in scenarios where IRQ work remains busy for extended
periods. By incorporating cond_resched(), the CPU is periodically yielded
to the scheduler, allowing other tasks to execute and enhancing overall
system responsiveness.
Signed-off-by: Steven Davis <goldside000@outlook.com>
---
kernel/irq_work.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 2f4fb336dda1..bdc478979ee6 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -295,9 +295,17 @@ void irq_work_sync(struct irq_work *work)
return;
}
- while (irq_work_is_busy(work))
+ int retry_count = 0;
+
+ while (irq_work_is_busy(work)) {
cpu_relax();
+
+ if (retry_count++ > 1000) {
+ cond_resched();
+ retry_count = 0;
+ }
}
+
EXPORT_SYMBOL_GPL(irq_work_sync);
static void run_irq_workd(unsigned int cpu)
--
2.39.5
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] irq_work: Improve CPU Responsiveness in irq_work_sync with cond_resched()
2024-09-18 15:23 [PATCH] irq_work: Improve CPU Responsiveness in irq_work_sync with cond_resched() Steven Davis
@ 2024-09-19 13:54 ` Thomas Gleixner
2024-09-19 15:25 ` Steven Davis
2024-09-21 14:42 ` kernel test robot
2024-09-21 15:13 ` kernel test robot
2 siblings, 1 reply; 5+ messages in thread
From: Thomas Gleixner @ 2024-09-19 13:54 UTC (permalink / raw)
To: Steven Davis, akpm
Cc: linux-kernel, Steven Davis, Peter Zijlstra, Ankur Arora,
Frederic Weisbecker
On Wed, Sep 18 2024 at 11:23, Steven Davis wrote:
> Add cond_resched() to the busy-wait loop in irq_work_sync to improve
> CPU responsiveness and prevent starvation of other tasks.
>
> Previously, the busy-wait loop used cpu_relax() alone, which, while
> reducing power consumption, could still lead to excessive CPU
> monopolization in scenarios where IRQ work remains busy for extended
> periods. By incorporating cond_resched(), the CPU is periodically yielded
> to the scheduler, allowing other tasks to execute and enhancing overall
> system responsiveness.
>
> - while (irq_work_is_busy(work))
> + int retry_count = 0;
> +
> + while (irq_work_is_busy(work)) {
> cpu_relax();
> +
> + if (retry_count++ > 1000) {
> + cond_resched();
> + retry_count = 0;
> + }
Did you verify that all callers are actually calling from preemptible
context?
If so, then we should just get rid of the loop waiting completely and
use the rcu_wait mechanism which RT uses.
Thanks,
tglx
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] irq_work: Improve CPU Responsiveness in irq_work_sync with cond_resched()
2024-09-19 13:54 ` Thomas Gleixner
@ 2024-09-19 15:25 ` Steven Davis
0 siblings, 0 replies; 5+ messages in thread
From: Steven Davis @ 2024-09-19 15:25 UTC (permalink / raw)
To: tglx; +Cc: akpm, ankur.a.arora, frederic, goldside000, linux-kernel, peterz
On Thu, 19 Sep 2024 at 15:54:21 +0200, Thomas Gleixner wrote:
> On Wed, Sep 18 2024 at 11:23, Steven Davis wrote:
>> Add cond_resched() to the busy-wait loop in irq_work_sync to improve
>> CPU responsiveness and prevent starvation of other tasks.
>>
>> Previously, the busy-wait loop used cpu_relax() alone, which, while
>> reducing power consumption, could still lead to excessive CPU
>> monopolization in scenarios where IRQ work remains busy for extended
>> periods. By incorporating cond_resched(), the CPU is periodically yielded
>> to the scheduler, allowing other tasks to execute and enhancing overall
>> system responsiveness.
>>
>> - while (irq_work_is_busy(work))
>> + int retry_count = 0;
>> +
>> + while (irq_work_is_busy(work)) {
>> cpu_relax();
>> +
>> + if (retry_count++ > 1000) {
>> + cond_resched();
>> + retry_count = 0;
>> + }
>
> Did you verify that all callers are actually calling from preemptible
> context?
Yes, I reviewed the 11 calls to irq_work_sync, and they all seem to
occur in preemptible contexts.
> If so, then we should just get rid of the loop waiting completely and
> use the rcu_wait mechanism which RT uses.
Will do that soon. Thanks for the suggestion.
Steven
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] irq_work: Improve CPU Responsiveness in irq_work_sync with cond_resched()
2024-09-18 15:23 [PATCH] irq_work: Improve CPU Responsiveness in irq_work_sync with cond_resched() Steven Davis
2024-09-19 13:54 ` Thomas Gleixner
@ 2024-09-21 14:42 ` kernel test robot
2024-09-21 15:13 ` kernel test robot
2 siblings, 0 replies; 5+ messages in thread
From: kernel test robot @ 2024-09-21 14:42 UTC (permalink / raw)
To: Steven Davis, akpm; +Cc: oe-kbuild-all, linux-kernel, Steven Davis
Hi Steven,
kernel test robot noticed the following build errors:
[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linus/master v6.11 next-20240920]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Steven-Davis/irq_work-Improve-CPU-Responsiveness-in-irq_work_sync-with-cond_resched/20240918-232606
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/SJ2P223MB10263844181902531B671FB6F7622%40SJ2P223MB1026.NAMP223.PROD.OUTLOOK.COM
patch subject: [PATCH] irq_work: Improve CPU Responsiveness in irq_work_sync with cond_resched()
config: parisc-allnoconfig (https://download.01.org/0day-ci/archive/20240921/202409212211.Lopmt0MK-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 14.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240921/202409212211.Lopmt0MK-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202409212211.Lopmt0MK-lkp@intel.com/
All errors (new ones prefixed by >>):
kernel/irq_work.c: In function 'irq_work_sync':
>> kernel/irq_work.c:311:13: error: invalid storage class for function 'run_irq_workd'
311 | static void run_irq_workd(unsigned int cpu)
| ^~~~~~~~~~~~~
>> kernel/irq_work.c:316:13: error: invalid storage class for function 'irq_workd_setup'
316 | static void irq_workd_setup(unsigned int cpu)
| ^~~~~~~~~~~~~~~
>> kernel/irq_work.c:323:35: error: initializer element is not constant
323 | .setup = irq_workd_setup,
| ^~~~~~~~~~~~~~~
kernel/irq_work.c:323:35: note: (near initialization for 'irqwork_threads.setup')
kernel/irq_work.c:325:35: error: initializer element is not constant
325 | .thread_fn = run_irq_workd,
| ^~~~~~~~~~~~~
kernel/irq_work.c:325:35: note: (near initialization for 'irqwork_threads.thread_fn')
>> kernel/irq_work.c:329:19: error: invalid storage class for function 'irq_work_init_threads'
329 | static __init int irq_work_init_threads(void)
| ^~~~~~~~~~~~~~~~~~~~~
In file included from arch/parisc/include/asm/alternative.h:18,
from arch/parisc/include/asm/barrier.h:5,
from include/asm-generic/bitops/generic-non-atomic.h:7,
from include/linux/bitops.h:29,
from include/linux/kernel.h:23,
from arch/parisc/include/asm/bug.h:5,
from include/linux/bug.h:5,
from kernel/irq_work.c:9:
kernel/irq_work.c:335:16: error: initializer element is not constant
335 | early_initcall(irq_work_init_threads);
| ^~~~~~~~~~~~~~~~~~~~~
include/linux/init.h:270:55: note: in definition of macro '____define_initcall'
270 | __attribute__((__section__(__sec))) = fn;
| ^~
include/linux/init.h:280:9: note: in expansion of macro '__unique_initcall'
280 | __unique_initcall(fn, id, __sec, __initcall_id(fn))
| ^~~~~~~~~~~~~~~~~
include/linux/init.h:282:35: note: in expansion of macro '___define_initcall'
282 | #define __define_initcall(fn, id) ___define_initcall(fn, id, .initcall##id)
| ^~~~~~~~~~~~~~~~~~
include/linux/init.h:289:41: note: in expansion of macro '__define_initcall'
289 | #define early_initcall(fn) __define_initcall(fn, early)
| ^~~~~~~~~~~~~~~~~
kernel/irq_work.c:335:1: note: in expansion of macro 'early_initcall'
335 | early_initcall(irq_work_init_threads);
| ^~~~~~~~~~~~~~
>> kernel/irq_work.c:335:1: error: expected declaration or statement at end of input
vim +/run_irq_workd +311 kernel/irq_work.c
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 310
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 @311 static void run_irq_workd(unsigned int cpu)
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 312 {
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 313 irq_work_run_list(this_cpu_ptr(&lazy_list));
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 314 }
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 315
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 @316 static void irq_workd_setup(unsigned int cpu)
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 317 {
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 318 sched_set_fifo_low(current);
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 319 }
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 320
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 321 static struct smp_hotplug_thread irqwork_threads = {
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 322 .store = &irq_workd,
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 @323 .setup = irq_workd_setup,
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 324 .thread_should_run = irq_workd_should_run,
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 325 .thread_fn = run_irq_workd,
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 326 .thread_comm = "irq_work/%u",
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 327 };
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 328
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 @329 static __init int irq_work_init_threads(void)
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 330 {
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 331 if (IS_ENABLED(CONFIG_PREEMPT_RT))
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 332 BUG_ON(smpboot_register_percpu_thread(&irqwork_threads));
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 333 return 0;
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 334 }
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 @335 early_initcall(irq_work_init_threads);
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] irq_work: Improve CPU Responsiveness in irq_work_sync with cond_resched()
2024-09-18 15:23 [PATCH] irq_work: Improve CPU Responsiveness in irq_work_sync with cond_resched() Steven Davis
2024-09-19 13:54 ` Thomas Gleixner
2024-09-21 14:42 ` kernel test robot
@ 2024-09-21 15:13 ` kernel test robot
2 siblings, 0 replies; 5+ messages in thread
From: kernel test robot @ 2024-09-21 15:13 UTC (permalink / raw)
To: Steven Davis, akpm; +Cc: llvm, oe-kbuild-all, linux-kernel, Steven Davis
Hi Steven,
kernel test robot noticed the following build errors:
[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linus/master v6.11 next-20240920]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Steven-Davis/irq_work-Improve-CPU-Responsiveness-in-irq_work_sync-with-cond_resched/20240918-232606
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/SJ2P223MB10263844181902531B671FB6F7622%40SJ2P223MB1026.NAMP223.PROD.OUTLOOK.COM
patch subject: [PATCH] irq_work: Improve CPU Responsiveness in irq_work_sync with cond_resched()
config: um-allnoconfig (https://download.01.org/0day-ci/archive/20240921/202409212247.nX8LW3Px-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240921/202409212247.nX8LW3Px-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202409212247.nX8LW3Px-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from kernel/irq_work.c:14:
In file included from include/linux/hardirq.h:11:
In file included from arch/um/include/asm/hardirq.h:5:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:14:
In file included from arch/um/include/asm/io.h:24:
include/asm-generic/io.h:548:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
548 | val = __raw_readb(PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:561:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
561 | val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
| ~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
| ^
In file included from kernel/irq_work.c:14:
In file included from include/linux/hardirq.h:11:
In file included from arch/um/include/asm/hardirq.h:5:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:14:
In file included from arch/um/include/asm/io.h:24:
include/asm-generic/io.h:574:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
574 | val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
| ~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
| ^
In file included from kernel/irq_work.c:14:
In file included from include/linux/hardirq.h:11:
In file included from arch/um/include/asm/hardirq.h:5:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:14:
In file included from arch/um/include/asm/io.h:24:
include/asm-generic/io.h:585:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
585 | __raw_writeb(value, PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:595:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
595 | __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:605:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
605 | __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:693:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
693 | readsb(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:701:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
701 | readsw(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:709:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
709 | readsl(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:718:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
718 | writesb(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:727:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
727 | writesw(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:736:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
736 | writesl(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
>> kernel/irq_work.c:312:1: error: function definition is not allowed here
312 | {
| ^
kernel/irq_work.c:317:1: error: function definition is not allowed here
317 | {
| ^
>> kernel/irq_work.c:323:13: error: use of undeclared identifier 'irq_workd_setup'
323 | .setup = irq_workd_setup,
| ^
>> kernel/irq_work.c:325:28: error: use of undeclared identifier 'run_irq_workd'
325 | .thread_fn = run_irq_workd,
| ^
kernel/irq_work.c:330:1: error: function definition is not allowed here
330 | {
| ^
>> kernel/irq_work.c:335:16: error: use of undeclared identifier 'irq_work_init_threads'; did you mean 'irqwork_threads'?
335 | early_initcall(irq_work_init_threads);
| ^~~~~~~~~~~~~~~~~~~~~
| irqwork_threads
include/linux/init.h:289:47: note: expanded from macro 'early_initcall'
289 | #define early_initcall(fn) __define_initcall(fn, early)
| ^
include/linux/init.h:282:54: note: expanded from macro '__define_initcall'
282 | #define __define_initcall(fn, id) ___define_initcall(fn, id, .initcall##id)
| ^
include/linux/init.h:280:20: note: expanded from macro '___define_initcall'
280 | __unique_initcall(fn, id, __sec, __initcall_id(fn))
| ^
include/linux/init.h:274:22: note: expanded from macro '__unique_initcall'
274 | ____define_initcall(fn, \
| ^
include/linux/init.h:270:41: note: expanded from macro '____define_initcall'
270 | __attribute__((__section__(__sec))) = fn;
| ^
kernel/irq_work.c:321:34: note: 'irqwork_threads' declared here
321 | static struct smp_hotplug_thread irqwork_threads = {
| ^
>> kernel/irq_work.c:335:1: error: initializing 'initcall_t' (aka 'int (*)(void)') with an expression of incompatible type 'struct smp_hotplug_thread'
335 | early_initcall(irq_work_init_threads);
| ^ ~~~~~~~~~~~~~~~~~~~~~
include/linux/init.h:289:29: note: expanded from macro 'early_initcall'
289 | #define early_initcall(fn) __define_initcall(fn, early)
| ^ ~~
include/linux/init.h:282:35: note: expanded from macro '__define_initcall'
282 | #define __define_initcall(fn, id) ___define_initcall(fn, id, .initcall##id)
| ^ ~~
include/linux/init.h:280:2: note: expanded from macro '___define_initcall'
280 | __unique_initcall(fn, id, __sec, __initcall_id(fn))
| ^ ~~
note: (skipping 3 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
include/linux/compiler_types.h:83:23: note: expanded from macro '___PASTE'
83 | #define ___PASTE(a,b) a##b
| ^
<scratch space>:69:1: note: expanded from here
69 | __initcall__kmod_irq_work__193_335_irq_work_init_threadsearly
| ^
include/linux/init.h:269:20: note: expanded from macro '____define_initcall'
269 | static initcall_t __name __used \
| ^
270 | __attribute__((__section__(__sec))) = fn;
| ~~
>> kernel/irq_work.c:335:39: error: expected '}'
335 | early_initcall(irq_work_init_threads);
| ^
kernel/irq_work.c:287:1: note: to match this '{'
287 | {
| ^
12 warnings and 8 errors generated.
vim +312 kernel/irq_work.c
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 310
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 311 static void run_irq_workd(unsigned int cpu)
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 @312 {
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 313 irq_work_run_list(this_cpu_ptr(&lazy_list));
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 314 }
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 315
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 316 static void irq_workd_setup(unsigned int cpu)
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 317 {
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 318 sched_set_fifo_low(current);
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 319 }
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 320
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 @321 static struct smp_hotplug_thread irqwork_threads = {
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 322 .store = &irq_workd,
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 @323 .setup = irq_workd_setup,
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 324 .thread_should_run = irq_workd_should_run,
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 @325 .thread_fn = run_irq_workd,
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 326 .thread_comm = "irq_work/%u",
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 327 };
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 328
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 329 static __init int irq_work_init_threads(void)
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 330 {
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 331 if (IS_ENABLED(CONFIG_PREEMPT_RT))
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 332 BUG_ON(smpboot_register_percpu_thread(&irqwork_threads));
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 333 return 0;
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 334 }
b4c6f86ec2f648 Sebastian Andrzej Siewior 2021-10-07 @335 early_initcall(irq_work_init_threads);
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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2024-09-18 15:23 [PATCH] irq_work: Improve CPU Responsiveness in irq_work_sync with cond_resched() Steven Davis
2024-09-19 13:54 ` Thomas Gleixner
2024-09-19 15:25 ` Steven Davis
2024-09-21 14:42 ` kernel test robot
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