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From: Rich Felker <dalias@libc.org>
To: musl@lists.openwall.com
Subject: Re: Why musl define PAGE_SIZE
Date: Fri, 11 Sep 2015 16:10:11 -0400	[thread overview]
Message-ID: <20150911201011.GY17773@brightrain.aerifal.cx> (raw)
In-Reply-To: <20150911194359.GB1965@newbook>

On Fri, Sep 11, 2015 at 12:44:02PM -0700, Isaac Dunham wrote:
> On Fri, Sep 11, 2015 at 03:28:52PM -0400, Yuxin Ren wrote:
> > Hi,
> > 
> > I found in the bits/limits.h file, musl defines PAGE_SIZE macro .
> > I think this macro is always defined by operating system, not libc.
> > 
> > Why does musl define this marco?
> 
> It's required to be in limits.h, which has to be provided by libc for a
> full implementation.

It's not required. Lack of a definition means you have to query the
value at runtime with sysconf(_SC_PAGESIZE). But failure to provide a
value on platforms where it is constant just gratuitously pessimizes
programs that need to know page size.

Rich


  parent reply	other threads:[~2015-09-11 20:10 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-11 19:28 Yuxin Ren
2015-09-11 19:44 ` Isaac Dunham
2015-09-11 19:53   ` Yuxin Ren
2015-09-11 20:10   ` Rich Felker [this message]
2015-09-11 20:01 ` Rich Felker

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