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From: Florian Weimer via Libc-alpha <libc-alpha@sourceware.org>
To: DJ Delorie <dj@redhat.com>
Cc: Wilco Dijkstra <Wilco.Dijkstra@arm.com>,  libc-alpha@sourceware.org
Subject: Re: [PATCH] malloc: Use correct C11 atomics for fastbin
Date: Fri, 02 Dec 2022 07:36:03 +0100	[thread overview]
Message-ID: <87sfhytir0.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <xnbkom75l3.fsf@greed.delorie.com> (DJ Delorie's message of "Fri,  02 Dec 2022 00:11:20 -0500")

* DJ Delorie:

> Wilco Dijkstra via Libc-alpha <libc-alpha@sourceware.org> writes:
>> +/* Atomically pop from the fastbin list.  The arena lock must be held to
>> +   block other threads removing entries, avoiding the ABA issue.  */
>
> If the arena lock must be held anyway, why go through the compare and
> exchange overhead?  We know we're the only thread accessing it.

Other threads are adding entries without the arena lock.

Thanks,
Florian


  reply	other threads:[~2022-12-02  6:36 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-21 16:09 [PATCH] malloc: Use correct C11 atomics for fastbin Wilco Dijkstra via Libc-alpha
2022-11-21 16:18 ` Florian Weimer via Libc-alpha
2022-11-21 16:55   ` Wilco Dijkstra via Libc-alpha
2022-11-21 16:56     ` Wilco Dijkstra via Libc-alpha
2022-11-21 17:00     ` Florian Weimer via Libc-alpha
2022-12-02  5:11 ` DJ Delorie via Libc-alpha
2022-12-02  6:36   ` Florian Weimer via Libc-alpha [this message]
2022-12-02 10:56     ` Wilco Dijkstra via Libc-alpha
2022-12-02 11:24       ` Florian Weimer via Libc-alpha
2022-12-02 12:02         ` Wilco Dijkstra via Libc-alpha
2022-12-02 18:55           ` DJ Delorie via Libc-alpha
2022-12-05 18:39             ` Zack Weinberg via Libc-alpha
2022-12-06 16:19               ` DJ Delorie via Libc-alpha
2022-12-12  3:35                 ` Zack Weinberg via Libc-alpha
2022-12-12 11:57                   ` Florian Weimer via Libc-alpha
2022-12-12 11:56                 ` Florian Weimer via Libc-alpha
2022-12-06 13:29             ` Wilco Dijkstra via Libc-alpha
2022-12-06 13:37               ` Adhemerval Zanella Netto via Libc-alpha
2022-12-06 14:31                 ` Zack Weinberg via Libc-alpha
2022-12-06 16:23               ` DJ Delorie via Libc-alpha
2022-12-15 15:43                 ` Wilco Dijkstra via Libc-alpha
2022-12-02 18:55     ` DJ Delorie via Libc-alpha
  -- strict thread matches above, loose matches on Subject: below --
2022-12-06 15:04 Wilco Dijkstra via Libc-alpha

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