From: "Václav Haisman" <vhaisman@gmail.com>
To: cygwin-patches@cygwin.com
Subject: Re: Fwd: [PATCH] spinlock spin with pause instruction
Date: Sat, 12 Mar 2016 08:14:00 -0000 [thread overview]
Message-ID: <56E3CFB1.5080906@gmail.com> (raw)
In-Reply-To: <56E3B674.7020702@maxrnd.com>
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On 12.3.2016 07:25, Mark Geisert wrote:
> Václav Haisman wrote:
>> Hi.
>>
>> I have noticed that Cygwin's spinlock goes into heavy sleeping code
>> for each spin. It seems it would be a good idea to actually try to
>> spin a bit first. There is this 'pause' instruction which let's the
>> CPU make such busy loops be less busy. Here is a patch to do this.
>
> I wanted to try out this patch but compilation is failing on the
> "unlikely" call. Is that a macro that needs defining or something else?
> Thanks,
>
> ..mark
>
`unlikely()` is a macro defined in `miscfuncs.h`, right below header
guard:
<https://cygwin.com/git/gitweb.cgi?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/miscfuncs.h;h=3a9f0258c6cbb62b8d51e96c0c5542b70659e17b;hb=HEAD>
--
VH
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prev parent reply other threads:[~2016-03-12 8:14 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAKw7uVgrjqZVznRMoCbsjyz4YXast5YtAAmpWQorOw7YXqbOhw@mail.gmail.com>
2016-03-11 10:28 ` Václav Haisman
2016-03-11 13:04 ` Corinna Vinschen
2016-03-12 6:25 ` Fwd: " Mark Geisert
2016-03-12 8:14 ` Václav Haisman [this message]
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