Re: [PATCH v3 2/5] kmemleak: add clear command support

[Luis R. Rodriguez]

On Tue, Sep 8, 2009 at 9:11 AM, Catalin Marinas<catalin.marinas@xxxxxxx> wrote:
> On Fri, 2009-09-04 at 17:44 -0700, Luis R. Rodriguez wrote:
>> Â/*
>> + * We use grey instead of black to ensure we can do future
>> + * scans on the same objects. If we did not do future scans
>> + * these black objects could potentially contain references to
>> + * newly allocated objects in the future and we'd end up with
>> + * false positives.
>> + */
>> +static void kmemleak_clear(void)
>> +{
>> + Â Â struct kmemleak_object *object;
>> + Â Â unsigned long flags;
>> +
>> + Â Â stop_scan_thread();
>> +
>> + Â Â rcu_read_lock();
>> + Â Â list_for_each_entry_rcu(object, &object_list, object_list) {
>> + Â Â Â Â Â Â spin_lock_irqsave(&object->lock, flags);
>> + Â Â Â Â Â Â if ((object->flags & OBJECT_REPORTED) &&
>> + Â Â Â Â Â Â Â Â unreferenced_object(object))
>> + Â Â Â Â Â Â Â Â Â Â object->min_count = -1;
>> + Â Â Â Â Â Â spin_unlock_irqrestore(&object->lock, flags);
>> + Â Â }
>> + Â Â rcu_read_unlock();
>> +
>> + Â Â start_scan_thread();
>> +}
>
> Do we need to stop and start the scanning thread here? When starting it,
> it will trigger a memory scan automatically. I don't think we want this
> as a side-effect, so I dropped these lines from your patch.

OK thanks.

> Also you set min_count to -1 here which means black object, so a
> subsequent patch corrects it. I'll set min_count to 0 here in case
> anyone bisects over it.

Dah, thanks for catching that, seems I only fixed the named set.

  Luis
--
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/