Re: [patch 00/12] Slab defragmentation V3

Michal Piotrowski
2007-06-08T19:47:56Z

Christoph Lameter pisze:
> On Fri, 8 Jun 2007, Christoph Lameter wrote:
>
>> On Fri, 8 Jun 2007, Michal Piotrowski wrote:
>>
>>> Yes, it does. Thanks!
>> Ahhh... That leds to the discovery more sysfs problems. I need to make
>> sure not to be holding locks while calling into sysfs. More cleanup...
>
> Could you remove the trylock patch and see how this one fares? We may need
> both but this should avoid taking the slub_lock around any possible alloc
> of sysfs.
>
>

It's a bit tricky

cat ../sd2.patch | patch -p1
patching file mm/slub.c
Hunk #1 succeeded at 2194 (offset 15 lines).
Hunk #2 FAILED at 2653.
1 out of 2 hunks FAILED -- saving rejects to file mm/slub.c.rej
[michal@bitis-gabonica linux-work3]$ cat mm/slub.c.rej
***************
*** 2652,2677 ****
*/
s->objsize = max(s->objsize, (int)size);
s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
if (sysfs_slab_alias(s, name))
goto err;
- } else {
- s = kmalloc(kmem_size, GFP_KERNEL);
- if (s && kmem_cache_open(s, GFP_KERNEL, name,
size, align, flags, ctor)) {
- if (sysfs_slab_add(s)) {
- kfree(s);
- goto err;
- }
list_add(&s->list, &slab_caches);
raise_kswapd_order(s->order);
- } else
- kfree(s);
}
up_write(&slub_lock);
- return s;

err:
- up_write(&slub_lock);
if (flags & SLAB_PANIC)
panic("Cannot create slabcache %s\n", name);
else
--- 2653,2685 ----
*/
s->objsize = max(s->objsize, (int)size);
s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
+ up_write(&slub_lock);
+
if (sysfs_slab_alias(s, name))
goto err;
+
+ return s;
+ }
+
+ s = kmalloc(kmem_size, GFP_KERNEL);
+ if (s) {
+ if (kmem_cache_open(s, GFP_KERNEL, name,
size, align, flags, ctor)) {
list_add(&s->list, &slab_caches);
+ up_write(&slub_lock);
raise_kswapd_order(s->order);
+
+ if (sysfs_slab_add(s))
+ goto err;
+
+ return s;
+
+ }
+ kfree(s);
}
up_write(&slub_lock);

err:
if (flags & SLAB_PANIC)
panic("Cannot create slabcache %s\n", name);
else

Regards,
Michal

--
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-- Andrzej Sapkowski "Coś więcej"