Re: [git pull] core kernel fixes

From: Vegard Nossum
Date: Mon Jun 30 2008 - 15:51:37 EST


On Mon, Jun 30, 2008 at 9:46 PM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> On Mon, 30 Jun 2008, Vegard Nossum wrote:
>> On Mon, Jun 30, 2008 at 8:20 PM, Ingo Molnar <mingo@xxxxxxx> wrote:
>> > The patch was tested with our standard tests so it's certainly good in
>> > practice - but i havent specifically tried your testcase (maybe Thomas
>> > has). Can you see any problem with the fix?
>>
>> Well, what I can see is that the patch that was committed has some
>> missing changes. In Daniel's patch:
>>
>> -repeat:
>> - spin_lock(&pool_lock);
>> + spin_lock_irqsave(&pool_lock, flags);
>> if (obj_pool.first) {
>> obj = hlist_entry(obj_pool.first, typeof(*obj), node);
>>
>> The patch that was committed:
>>
>> -repeat:
>> spin_lock(&pool_lock);
>> if (obj_pool.first) {
>> obj = hlist_entry(obj_pool.first, typeof(*obj), node);
>>
>> Was it not necessary to make the pool lock irq-safe in this place?
>>
>> For reference:
>>
>> Daniel's patch: http://lkml.org/lkml/2008/6/15/27
>> Actual commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=70c85057e0bde35eb56352a293ecb5d1641a0334;hp=e6100f23375c0c71ce595d04551fa6553b611918
>
> alloc_object() is called with interrupts disabled from __debug_object_init()

Ok, thanks for clearing that up! :-)

(I'm just wary of patches that mutate when they have my name on the top...)


Vegard

--
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
-- E. W. Dijkstra, EWD1036
--
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/