From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Florian Weimer <fw@deneb.enyo.de>
Cc: Thomas Gleixner <tglx@linutronix.de>,
linux-kernel <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
paulmck <paulmck@linux.ibm.com>,
Boqun Feng <boqun.feng@gmail.com>,
"H. Peter Anvin" <hpa@zytor.com>, Paul Turner <pjt@google.com>,
linux-api <linux-api@vger.kernel.org>,
Dmitry Vyukov <dvyukov@google.com>,
Neel Natu <neelnatu@google.com>, stable <stable@vger.kernel.org>
Subject: Re: [RFC PATCH for 5.8 1/4] sched: Fix unreliable rseq cpu_id for new tasks
Date: Tue, 7 Jul 2020 06:51:44 -0400 (EDT) [thread overview]
Message-ID: <1513249086.945.1594119104750.JavaMail.zimbra@efficios.com> (raw)
In-Reply-To: <87blkrzssa.fsf@mid.deneb.enyo.de>
----- On Jul 7, 2020, at 3:30 AM, Florian Weimer fw@deneb.enyo.de wrote:
> * Mathieu Desnoyers:
>
>> While integrating rseq into glibc and replacing glibc's sched_getcpu
>> implementation with rseq, glibc's tests discovered an issue with
>> incorrect __rseq_abi.cpu_id field value right after the first time
>> a newly created process issues sched_setaffinity.
>>
>> For the records, it triggers after building glibc and running tests, and
>> then issuing:
>>
>> for x in {1..2000} ; do posix/tst-affinity-static & done
>>
>> and shows up as:
>>
>> error: Unexpected CPU 2, expected 0
>> error: Unexpected CPU 2, expected 0
>> error: Unexpected CPU 2, expected 0
>> error: Unexpected CPU 2, expected 0
>> error: Unexpected CPU 138, expected 0
>> error: Unexpected CPU 138, expected 0
>> error: Unexpected CPU 138, expected 0
>> error: Unexpected CPU 138, expected 0
>
> As far as I can tell, the glibc reproducer no longer shows the issue
> with this patch applied.
>
> Tested-By: Florian Weimer <fweimer@redhat.com>
Thanks a lot Florian for your thorough review and testing !
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
next prev parent reply other threads:[~2020-07-07 10:51 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-06 20:49 [RFC PATCH for 5.8 0/4] rseq cpu_id ABI fix Mathieu Desnoyers
2020-07-06 20:49 ` [RFC PATCH for 5.8 1/4] sched: Fix unreliable rseq cpu_id for new tasks Mathieu Desnoyers
2020-07-07 7:30 ` Florian Weimer
2020-07-07 10:51 ` Mathieu Desnoyers [this message]
2020-07-06 20:49 ` [RFC PATCH for 5.8 2/4] rseq: Introduce RSEQ_FLAG_REGISTER Mathieu Desnoyers
2020-07-06 20:49 ` [RFC PATCH for 5.8 3/4] rseq: Introduce RSEQ_FLAG_RELIABLE_CPU_ID Mathieu Desnoyers
2020-07-07 7:29 ` Florian Weimer
2020-07-07 10:48 ` Mathieu Desnoyers
2020-07-07 11:32 ` Florian Weimer
2020-07-07 12:06 ` Mathieu Desnoyers
2020-07-07 18:53 ` Carlos O'Donell
2020-07-07 18:59 ` Mathieu Desnoyers
2020-07-08 8:31 ` Florian Weimer
2020-07-07 19:55 ` Florian Weimer
2020-07-08 15:33 ` Mathieu Desnoyers
2020-07-08 16:22 ` Christian Brauner
2020-07-08 16:36 ` Florian Weimer
2020-07-08 17:34 ` Mathieu Desnoyers
2020-07-09 12:49 ` Christian Brauner
2020-07-09 15:15 ` Mathieu Desnoyers
2020-07-11 15:54 ` Christian Brauner
2020-07-13 18:40 ` Mathieu Desnoyers
2020-07-06 20:49 ` [RFC PATCH for 5.8 4/4] rseq: selftests: Expect reliable cpu_id field Mathieu Desnoyers
2020-07-07 6:26 ` [RFC PATCH for 5.8 0/4] rseq cpu_id ABI fix Florian Weimer
2020-07-07 14:54 ` Florian Weimer
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