From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael Kerrisk (man-pages)" Subject: Re: [PATCH] remap_file_pages.2: Not actually useful on real files. Date: Thu, 08 May 2014 11:45:05 +0200 Message-ID: <536B5221.60407@gmail.com> References: <5de30c3a21531919712fc7df213c18b46e521225.1355955125.git.luto@amacapital.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5de30c3a21531919712fc7df213c18b46e521225.1355955125.git.luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org> Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Andy Lutomirski Cc: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-man@vger.kernel.org Andy, It's long after the fact, but... On 12/19/2012 11:12 PM, Andy Lutomirski wrote: > Linux commit 3ee6dafc677a68e461a7ddafc94a580ebab80735 caused > remap_file_pages to be emulated when used on real file. > > Signed-off-by: Andy Lutomirski > --- > man2/remap_file_pages.2 | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/man2/remap_file_pages.2 b/man2/remap_file_pages.2 > index f96f594..f6dee99 100644 > --- a/man2/remap_file_pages.2 > +++ b/man2/remap_file_pages.2 > @@ -148,6 +148,12 @@ The > .BR remap_file_pages () > system call appeared in Linux 2.5.46; > glibc support was added in version 2.3.3. > + > +.BR remap_file_pages () > +has no performance advantage over > +.BR mmap (2) > +when used on real (as opposed to purely in-memory) files as of Linux 2.6.23: > +on real files it creates a separate vma for each range. > .SH "CONFORMING TO" > The > .BR remap_file_pages () I've applied the above. I then tweaked it a little. Is the following okay: [[ Since Linux 2.6.23, .\" commit 3ee6dafc677a68e461a7ddafc94a580ebab80735 .BR remap_file_pages () has no performance advantage over .BR mmap (2) when used on real files: on real files it creates a separate VMA for each range. It does, however, continue to provide a performance advantage for files on memory-based filesystems. ]] ? Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html