From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael Kerrisk (man-pages)" Subject: Re: shmget.2: SHMALL & kernel version inconsistency ? Date: Mon, 28 Apr 2014 09:39:50 +0200 Message-ID: <535E05C6.10409@gmail.com> References: <20140427220916.GP18563@mraw.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20140427220916.GP18563-xazfMhTT2R0@public.gmane.org> Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Simon Paillard , linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: linux-man@vger.kernel.org On 04/28/2014 12:09 AM, Simon Paillard wrote: > Hi, >=20 >>>From shmget.2: > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > SHMALL System wide maximum of shared memory pages. Since Linux 2.= 2, > the default value for this limit is >=20 > SHMMAX / PAGE_SIZE * (SHMMNI / 16) >=20 > Assuming a 4kB page size, this formula yields (since Linux 2.= 4) > the value 2^20 (2,097,152). >=20 > On Linux, this limit can be read and modified via /proc/sys/ke= r=E2=80=90 > nel/shmall. > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >=20 > Linux 2.2 or 2.4 ? >=20 > I understand from lxr contant this is actually 2.4. > http://lxr.linux.no/#linux-old+v2.2.0/include/linux/shm.h#L53 > http://lxr.linux.no/#linux-old+v2.4.0/include/linux/shm.h#L15 Thanks, Simon. Yes, it should have been 2.4. The fix is in Git. Cheers, Michael =20 --=20 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