From: Peter Zijlstra <peterz@infradead.org>
To: Andy Lutomirski <luto@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Borislav Petkov <bp@alien8.de>, Brian Gerst <brgerst@gmail.com>,
Denys Vlasenko <dvlasenk@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Paul McKenney <paulmck@linux.vnet.ibm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: locking/atomic: Introduce atomic_try_cmpxchg()
Date: Fri, 24 Mar 2017 21:14:39 +0100 [thread overview]
Message-ID: <20170324201439.GY5680@worktop> (raw)
In-Reply-To: <CALCETrUwYUzTk_453WaxOE32RD1i=wBdQUcsrc9OvvtmPtoQ_Q@mail.gmail.com>
On Fri, Mar 24, 2017 at 12:16:11PM -0700, Andy Lutomirski wrote:
> On Fri, Mar 24, 2017 at 11:13 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> > Not to mention we cannot use the C11 atomics in kernel because we want
> > to be able to runtime patch LOCK prefixes when only 1 CPU is available.
>
> Is this really a show-stopper? I bet that objtool could be persuaded
> to emit a list of the locations of all those LOCK prefixes.
Ah, but its not _all_ LOCK prefixes. Some are needed even on UP, because
against hardware instead of other CPUs. Or again hypervisor instead of
other vCPU.
next prev parent reply other threads:[~2017-03-24 20:15 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-24 12:44 locking/atomic: Introduce atomic_try_cmpxchg() Dmitry Vyukov
2017-03-24 14:21 ` Peter Zijlstra
2017-03-24 14:23 ` Dmitry Vyukov
2017-03-24 16:41 ` Peter Zijlstra
2017-03-24 16:54 ` Andy Lutomirski
2017-03-24 17:23 ` Peter Zijlstra
2017-03-24 17:51 ` Dmitry Vyukov
2017-03-24 18:08 ` Peter Zijlstra
2017-03-24 18:13 ` Peter Zijlstra
2017-03-24 19:16 ` Andy Lutomirski
2017-03-24 19:20 ` Linus Torvalds
2017-03-24 19:27 ` Andy Lutomirski
2017-03-24 20:15 ` Peter Zijlstra
2017-03-24 20:14 ` Peter Zijlstra [this message]
2017-03-24 20:21 ` Andy Lutomirski
2017-03-24 18:16 ` Dmitry Vyukov
2017-03-24 18:00 ` Peter Zijlstra
2017-03-24 18:04 ` Peter Zijlstra
2017-03-24 18:45 ` Andy Lutomirski
2017-03-24 19:17 ` Linus Torvalds
2017-03-24 21:23 ` Peter Zijlstra
2017-03-25 7:51 ` Peter Zijlstra
2017-03-25 18:00 ` Linus Torvalds
2017-03-25 18:20 ` Peter Zijlstra
2017-03-25 18:28 ` Linus Torvalds
2017-03-25 18:34 ` Linus Torvalds
2017-03-25 21:13 ` Peter Zijlstra
2017-03-25 22:08 ` Linus Torvalds
2017-03-27 9:48 ` Peter Zijlstra
2017-03-24 20:22 ` Peter Zijlstra
2017-03-24 20:27 ` Andy Lutomirski
2017-03-24 21:07 ` Peter Zijlstra
2017-03-24 19:08 ` Linus Torvalds
2017-03-24 20:46 ` Peter Zijlstra
2017-03-24 20:58 ` Linus Torvalds
2017-03-27 12:16 ` Peter Zijlstra
2017-03-27 13:45 ` Dmitry Vyukov
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