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>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Matt Turner <mattst88@gmail.com>,
Russell King <linux@armlinux.org.uk>, Guo Ren <guoren@kernel.org>,
Michal Simek <monstr@monstr.eu>,
Dinh Nguyen <dinguyen@kernel.org>,
Jonas Bonn <jonas@southpole.se>,
Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
Stafford Horne <shorne@gmail.com>,
"James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>,
Helge Deller <deller@gmx.de>,
Michael Ellerman <mpe@ellerman.id.au>,
Nicholas Piggin <npiggin@gmail.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Rich Felker <dalias@libc.org>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
"David S. Miller" <davem@davemloft.net>,
Andreas Larsson <andreas@gaisler.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Juri Lelli <juri.lelli@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Valentin Schneider <vschneid@redhat.com>,
Andrew Donnellan <ajd@linux.ibm.com>,
Benjamin Gray <bgray@linux.ibm.com>,
Frederic Weisbecker <frederic@kernel.org>,
Xin Li <xin3.li@intel.com>, Kees Cook <keescook@chromium.org>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Tony Battersby <tonyb@cybernetics.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Brian Gerst <brgerst@gmail.com>,
Leonardo Bras <leobras@redhat.com>,
Imran Khan <imran.f.khan@oracle.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Rik van Riel <riel@surriel.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
David Vernet <void@manifault.com>,
Julia Lawall <julia.lawall@inria.fr>,
linux-alpha@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org,
linux-openrisc@vger.kernel.org, linux-parisc@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org,
sparclinux@vger.kernel.org, linux-pm@vger.kernel.org,
x86@kernel.org
Subject: Re: [PATCH v2 00/14] Introducing TIF_NOTIFY_IPI flag
Date: Sat, 15 Jun 2024 03:42:56 +0200 [thread overview]
Message-ID: <20240615014256.GQ8774@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <CAKfTPtBTxhbmh=605TJ9sRw-nFu6w-KY7QpAxRUh5AjhQWa2ig@mail.gmail.com>
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
The converse problem is that you're adding a bunch of atomic ops that
might be avoided.
It might now need to set both the RESCHED and IPI flags -- and clear
them again.
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <peterz@infradead.org>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Juri Lelli <juri.lelli@redhat.com>, Rich Felker <dalias@libc.org>,
Andreas Larsson <andreas@gaisler.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org,
"James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>,
linux-openrisc@vger.kernel.org, Guo Ren <guoren@kernel.org>,
linux-csky@vger.kernel.org, David Vernet <void@manifault.com>,
"H. Peter Anvin" <hpa@zytor.com>, Borislav Petkov <bp@alien8.de>,
Thomas Gleixner <tglx@linutronix.de>,
Kees Cook <keescook@chromium.org>,
Jonas Bonn <jonas@southpole.se>,
Valentin Schneider <vschneid@redhat.com>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
linux-sh@vger.kernel.org, Helge Deller <deller@gmx.de>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Russell King <linux@armlinux.org.uk>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Tony Battersby <tonyb@cybernetics.com>,
Ingo Molnar <mingo@redhat.com>,
sparclinux@vger.kernel.org, Mel Gorman <mgorman@suse.de>,
"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Matt Turner <mattst88@gmail.com>,
Benjamin Gray <bgray@linux.ibm.com>,
Andrew Donnellan <ajd@linux.ibm.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Rik van Riel <riel@surriel.com>, Brian Gerst <brgerst@gmail.com>,
Frederic Weisbecker <frederic@kernel.org>,
Xin Li <xin3.li@intel.com>,
Richard Henderson <richard.henderson@linaro.org>,
linuxppc-dev@lists.ozlabs.org,
Nicholas Piggin <npiggin@gmail.com>,
Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Steven Rostedt <rostedt@goodmis.org>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
Bjorn Helgaas <bhelgaas@google.com>,
Stafford Horne <shorne@gmail.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
linux-arm-kernel@lists.infradead.org,
Ben Segall <bsegall@google.com>, Michal Simek <monstr@monstr.eu>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
linux-parisc@vger.kernel.org,
Tim Chen <tim.c.chen@linux.intel.com>,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
Julia Lawall <julia.lawall@inria.fr>,
Dinh Nguyen <dinguyen@kernel.org>,
Leonardo Bras <leobras@redhat.com>,
"Gautham R. Shenoy" <gautham.shenoy@amd.com>,
linux-alpha@vger.kernel.org, Imran Khan <imran.f.khan@oracle.com>,
K Prateek Nayak <kprateek.nayak@amd.com>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH v2 00/14] Introducing TIF_NOTIFY_IPI flag
Date: Sat, 15 Jun 2024 03:42:56 +0200 [thread overview]
Message-ID: <20240615014256.GQ8774@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <CAKfTPtBTxhbmh=605TJ9sRw-nFu6w-KY7QpAxRUh5AjhQWa2ig@mail.gmail.com>
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
The converse problem is that you're adding a bunch of atomic ops that
might be avoided.
It might now need to set both the RESCHED and IPI flags -- and clear
them again.
next prev parent reply other threads:[~2024-06-15 1:43 UTC|newest]
Thread overview: 49+ 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 18:15 ` 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 ` 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 ` 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 ` 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 ` 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 9:28 ` Peter Zijlstra
2024-06-14 10:48 ` Vincent Guittot
2024-06-14 10:48 ` Vincent Guittot
2024-06-14 16:31 ` Chen Yu
2024-06-14 16:31 ` Chen Yu
2024-06-17 8:33 ` K Prateek Nayak
2024-06-17 8:33 ` K Prateek Nayak
2024-06-18 7:49 ` Chen Yu
2024-06-18 7:49 ` Chen Yu
2024-06-18 18:33 ` K Prateek Nayak
2024-06-18 18:33 ` K Prateek Nayak
2024-06-20 7:30 ` Chen Yu
2024-06-20 7:30 ` Chen Yu
2024-06-15 1:28 ` Peter Zijlstra
2024-06-15 1:28 ` Peter Zijlstra
2024-06-15 1:45 ` Peter Zijlstra
2024-06-15 1:45 ` Peter Zijlstra
2024-06-16 14:57 ` Vincent Guittot
2024-06-16 14:57 ` Vincent Guittot
2024-06-17 5:52 ` K Prateek Nayak
2024-06-17 5:52 ` K Prateek Nayak
2024-06-15 1:42 ` Peter Zijlstra [this message]
2024-06-15 1:42 ` Peter Zijlstra
2024-06-15 14:26 ` Russell King (Oracle)
2024-06-15 14:26 ` Russell King (Oracle)
2024-06-17 4:35 ` K Prateek Nayak
2024-06-17 4:35 ` K Prateek Nayak
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