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From: Peter Zijlstra <peterz@infradead.org>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>,
	linux-kernel@vger.kernel.org,
	"Gautham R. Shenoy" <gautham.shenoy@amd.com>,
	Richard Henderson <richard.henderson@linaro.org>,
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	x86@kernel.org
Subject: Re: [PATCH v2 00/14] Introducing TIF_NOTIFY_IPI flag
Date: Sat, 15 Jun 2024 03:45:21 +0200	[thread overview]
Message-ID: <20240615014521.GR8774@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20240615012814.GP8774@noisy.programming.kicks-ass.net>

On Sat, Jun 15, 2024 at 03:28:14AM +0200, Peter Zijlstra wrote:
> On Fri, Jun 14, 2024 at 12:48:37PM +0200, Vincent Guittot wrote:

> > The main problem is that need_resched becomes somewhat meaningless
> > because it doesn't  only mean "I need to resched a task" and we have
> > to add more tests around even for those not using polling
> 
> True, however we already had some of that by having the wakeup list,
> that made nr_running less 'reliable'.

Doesn't using !idle_cpu() instead of need_resched() in those balance
paths already do the right thing?

Checking need_resched() as an indicator of it getting work is already a
bit an assumption.

Also, Ingo, idle_cpu() and friends don't really belong in syscalls.c...

  reply	other threads:[~2024-06-15  1:45 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-06-13 18:15 [PATCH v2 00/14] Introducing TIF_NOTIFY_IPI flag K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 01/14] thread_info: Add helpers to test and clear TIF_NOTIFY_IPI K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 02/14] sched: Define a need_resched_or_ipi() helper and use it treewide K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 03/14] sched/core: Use TIF_NOTIFY_IPI to notify an idle CPU in TIF_POLLING mode of pending IPI K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 04/14] x86/thread_info: Introduce TIF_NOTIFY_IPI flag K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 05/14] arm/thread_info: " K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 06/14] alpha/thread_info: " K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 07/14] openrisc/thread_info: " K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 08/14] powerpc/thread_info: " K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 09/14] sh/thread_info: " K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 10/14] sparc/thread_info: " K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 11/14] csky/thread_info: " K Prateek Nayak
2024-06-15 17:13   ` Guo Ren
2024-06-13 18:16 ` [PATCH v2 12/14] parisc/thread_info: " K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 13/14] nios2/thread_info: " K Prateek Nayak
2024-06-13 18:16 ` [PATCH v2 14/14] microblaze/thread_info: " K Prateek Nayak
2024-06-14  9:28 ` [PATCH v2 00/14] Introducing " Peter Zijlstra
2024-06-14 10:48   ` Vincent Guittot
2024-06-14 16:31     ` Chen Yu
2024-06-17  8:33       ` K Prateek Nayak
2024-06-18  7:49         ` Chen Yu
2024-06-18 18:33           ` K Prateek Nayak
2024-06-20  7:30             ` Chen Yu
2024-06-15  1:28     ` Peter Zijlstra
2024-06-15  1:45       ` Peter Zijlstra [this message]
2024-06-16 14:57       ` Vincent Guittot
2024-06-17  5:52         ` K Prateek Nayak
2024-06-15  1:42     ` Peter Zijlstra
2024-06-15 14:26 ` Russell King (Oracle)
2024-06-17  4:35   ` K Prateek Nayak

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