Re: [patch 4/4] ipc: sem optimise simple operations

Manfred Spraul
2009-08-11T18:18:44Z

On 08/11/2009 01:09 PM, npiggin@suse.de wrote:
> Index: linux-2.6/include/linux/sem.h
> ===================================================================
> --- linux-2.6.orig/include/linux/sem.h
> +++ linux-2.6/include/linux/sem.h
> @@ -86,6 +86,8 @@ struct task_struct;
> struct sem {
> int semval; /* current value */
> int sempid; /* pid of last operation */
> + struct list_head negv_pending;
> + struct list_head zero_pending;
> };
>
struct sem is increased from 8 to 24 bytes.
Is that still ok? Are there any apps that use really lots of semaphores
(i.e.: far more than processes in the system?)

Postgres uses lots of small semaphore sets (each with 17 entries), I
never had access to other apps.