On Fri, 2014-05-02 at 15:16 +0200, Michael Kerrisk (man-pages) wrote: > Hi Manfred, > > On Mon, Apr 21, 2014 at 4:26 PM, Manfred Spraul > <manfred@xxxxxxxxxxxxxxxx> wrote: > > Hi all, > > > > the increase of SHMMAX/SHMALL is now a 4 patch series. > > I don't have ideas how to improve it further. > > On the assumption that your patches are heading to mainline, could you > send me a man-pages patch for the changes? It seems we're still behind here and the 3.16 merge window is already opened. Please consider this, and again feel free to add/modify as necessary. I think adding a note as below is enough and was hesitant to add a lot of details... Thanks. 8<-------------------------------------------------- From: Davidlohr Bueso <davidlohr@xxxxxx> Subject: [PATCH] shmget.2: document new limits for shmmax/shmall These limits have been recently enlarged and modifying them is no longer really necessary. Update the manpage. Signed-off-by: Davidlohr Bueso <davidlohr@xxxxxx> --- man2/shmget.2 | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/man2/shmget.2 b/man2/shmget.2 index f781048..77764ea 100644 --- a/man2/shmget.2 +++ b/man2/shmget.2 @@ -299,6 +299,11 @@ with 8kB page size, it yields 2^20 (1048576). On Linux, this limit can be read and modified via .IR /proc/sys/kernel/shmall . +As of Linux 3.16, the default value for this limit is increased to +.B ULONG_MAX - 2^24 +pages, which is as large as it can be without helping userspace overflow +the values. Modifying this limit is therefore discouraged. This is suitable +for both 32 and 64-bit systems. .TP .B SHMMAX Maximum size in bytes for a shared memory segment. @@ -306,6 +311,12 @@ Since Linux 2.2, the default value of this limit is 0x2000000 (32MB). On Linux, this limit can be read and modified via .IR /proc/sys/kernel/shmmax . +As of Linux 3.16, the default value for this limit is increased from 32Mb +to +.B ULONG_MAX - 2^24 +bytes, which is as large as it can be without helping userspace overflow +the values. Modifying this limit is therefore discouraged. This is suitable +for both 32 and 64-bit systems. .TP .B SHMMIN Minimum size in bytes for a shared memory segment: implementation -- 1.8.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>