linux/arch/powerpc/platforms/cell/spufs/gang.c
Arnd Bergmann 6263203ed6 [POWERPC] spufs: Add infrastructure needed for gang scheduling
Add the concept of a gang to spufs as a new type of object.
So far, this has no impact whatsover on scheduling, but makes
it possible to add that later.

A new type of object in spufs is now a spu_gang. It is created
with the spu_create system call with the flags argument set
to SPU_CREATE_GANG (0x2). Inside of a spu_gang, it
is then possible to create spu_context objects, which until
now was only possible at the root of spufs.

There is a new member in struct spu_context pointing to
the spu_gang it belongs to, if any. The spu_gang maintains
a list of spu_context structures that are its children.
This information can then be used in the scheduler in the
future.

There is still a bug that needs to be resolved in this
basic infrastructure regarding the order in which objects
are removed. When the spu_gang file descriptor is closed
before the spu_context descriptors, we leak the dentry
and inode for the gang. Any ideas how to cleanly solve
this are appreciated.

Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-10-05 09:21:01 +10:00

82 lines
1.9 KiB
C

/*
* SPU file system
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
*
* Author: Arnd Bergmann <arndb@de.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/list.h>
#include <linux/slab.h>
#include "spufs.h"
struct spu_gang *alloc_spu_gang(void)
{
struct spu_gang *gang;
gang = kzalloc(sizeof *gang, GFP_KERNEL);
if (!gang)
goto out;
kref_init(&gang->kref);
mutex_init(&gang->mutex);
INIT_LIST_HEAD(&gang->list);
out:
return gang;
}
static void destroy_spu_gang(struct kref *kref)
{
struct spu_gang *gang;
gang = container_of(kref, struct spu_gang, kref);
WARN_ON(gang->contexts || !list_empty(&gang->list));
kfree(gang);
}
struct spu_gang *get_spu_gang(struct spu_gang *gang)
{
kref_get(&gang->kref);
return gang;
}
int put_spu_gang(struct spu_gang *gang)
{
return kref_put(&gang->kref, &destroy_spu_gang);
}
void spu_gang_add_ctx(struct spu_gang *gang, struct spu_context *ctx)
{
mutex_lock(&gang->mutex);
ctx->gang = get_spu_gang(gang);
list_add(&ctx->gang_list, &gang->list);
gang->contexts++;
mutex_unlock(&gang->mutex);
}
void spu_gang_remove_ctx(struct spu_gang *gang, struct spu_context *ctx)
{
mutex_lock(&gang->mutex);
WARN_ON(ctx->gang != gang);
list_del_init(&ctx->gang_list);
gang->contexts--;
mutex_unlock(&gang->mutex);
put_spu_gang(gang);
}