linux-kernel - Re: [PATCH] Use NUMA node cpu mask in irq affinity

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <4F33CFAD.30602@redhat.com>
Date:	Thu, 09 Feb 2012 08:52:45 -0500
From:	Prarit Bhargava <prarit@...hat.com>
To:	Yinghai Lu <yinghai@...nel.org>
CC:	linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH] Use NUMA node cpu mask in irq affinity



On 02/08/2012 06:51 PM, Yinghai Lu wrote:
> On Wed, Feb 8, 2012 at 12:48 PM, Prarit Bhargava <prarit@...hat.com> wrote:
>> The irq affinity files (/proc/irq/.../smp_affinity) contain a mask that is used
>> to "pin" an irq to a set of cpus.  On boot this set is currently all cpus.
>> This can be incorrect as ACPI SRAT may tell us that a specific device or
>> bus is attached to a particular node and it's cpus.
>>
>> When setting up the irq affinity we should take into account the NUMA node
>> cpu mask by and'ing it into the irq's affinity mask.
>>
>> Signed-off-by: Prarit Bhargava <prarit@...hat.com>
>> Acked-by: Neil Horman <nhorman@...driver.com>
>> ---
>>  kernel/irq/manage.c |    2 ++
>>  1 files changed, 2 insertions(+), 0 deletions(-)
>>
>> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
>> index a9a9dbe..2fb3469 100644
>> --- a/kernel/irq/manage.c
>> +++ b/kernel/irq/manage.c
>> @@ -301,6 +301,8 @@ setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
>>        }
>>
>>        cpumask_and(mask, cpu_online_mask, set);
>> +       if (desc->irq_data.node != -1)
>> +               cpumask_and(mask, mask, cpumask_of_node(desc->irq_data.node));
>>        ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
>>        switch (ret) {
>>        case IRQ_SET_MASK_OK:
>> --
> 
> How about all cpus on that node get offlined?

Good point.  I guess that also goes to tglx's comments wondering what happens if the mask ends up being zero.

I'll think about that and send out a new patch shortly.

P.
> 
> Yinghai
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/