Re: [PATCH 7/4] ipc/mqueue: separate mqueue default value from maximum value

From: Doug Ledford
Date: Wed Oct 26 2011 - 13:31:49 EST


----- Original Message -----
> commit b231cca438 (message queues: increase range limits)
> changed mqueue default value when attr parameter is specified NULL
> from hard coded value to fs.mqueue.{msg,msgsize}_max sysctl value.
>
> This made large side effect. When user need to use two mqueue
> applications 1) using !NULL attr parameter and it require big
> message size and 2) using NULL attr parameter and only need small
> size message, app (1) require to raise fs.mqueue.msgsize_max and
> app (2) consume large memory size even though it doesn't need.
>
> Doug Ledford propsed to switch back it to static hard coded value.
> However it also has a compatibility problem. Some applications might
> started depend on the default value is tunable.
>
> The solution is to separate default value from maximum value.
>
> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxx>
> Cc: Doug Ledford <dledford@xxxxxxxxxx>
> Cc: Amerigo Wang <amwang@xxxxxxxxxx>
> Cc: Serge E. Hallyn <serue@xxxxxxxxxx>
> Cc: Jiri Slaby <jslaby@xxxxxxx>
> Cc: Joe Korty <joe.korty@xxxxxxxx>

Acked-by: Doug Ledford <dledford@xxxxxxxxxx>

> ---
> Documentation/sysctl/fs.txt | 7 +++++++
> include/linux/ipc_namespace.h | 3 +++
> ipc/mq_sysctl.c | 18 ++++++++++++++++++
> ipc/mqueue.c | 9 ++++++---
> ipc/msgutil.c | 2 ++
> 5 files changed, 36 insertions(+), 3 deletions(-)

--
Doug Ledford <dledford@xxxxxxxxxx>
GPG KeyID: 0E572FDD
http://people.redhat.com/dledford

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/