From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Roper Subject: Re: Possible typo in madvise(2) Date: Tue, 01 Apr 2014 15:22:54 -0400 Message-ID: <533B120E.1090406@umich.edu> References: <5334B14B.7070409@umich.edu> <533B0303.2000601@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <533B0303.2000601-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Michael Kerrisk (man-pages)" Cc: linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-man@vger.kernel.org Sorry for my confusion. Checking other sources I see MADV_DONTNEED results in modifications to private mappings being lost (the section on zero-filling non-file-backed pages address this, in retrospect) which clearly changes semantics. I had noticed that MADV_DONTFORK can result in different behavior after a fork (eg, a parent mmaps a file, madvises dontfork, then forks, and the child writes to the page -- with madvise, the page is updated, visible to both processes, as is the backing file, without it the child will segfault) and thought there might be a simple typo. Alex On 04/01/2014 02:18 PM, Michael Kerrisk (man-pages) wrote: > On 03/28/2014 12:16 AM, Alex Roper wrote: >> Version: Current git repo >> >> The first paragraph of DESCRIPTION states that madvise does not change >> the semantics of an application except in the case of MADV_DONTNEED, >> which I believe should read MADV_DONTFORK. > > Alex, > > MADV_DONTNEED does change the semantics. But, could you say more > about wht you think MADV_DONTFORK should have been written here > instead? (Perhaps some fix is needed to the page.) > > Thanks, > > Michael > -- 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