Patch "blk-mq: Include all present CPUs in the default queue mapping" has been added to the 4.9-stable tree

Patch "blk-mq: Include all present CPUs in the default queue mapping" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    blk-mq: Include all present CPUs in the default queue mapping

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     blk-mq-include-all-present-cpus-in-the-default-queue-mapping.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 5f042e7cbd9ebd3580077dcdc21f35e68c2adf5f Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Mon, 26 Jun 2017 12:20:56 +0200
Subject: blk-mq: Include all present CPUs in the default queue mapping

From: Christoph Hellwig <hch@lst.de>

commit 5f042e7cbd9ebd3580077dcdc21f35e68c2adf5f upstream.

This way we get a nice distribution independent of the current cpu
online / offline state.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <keith.busch@intel.com>
Cc: linux-block@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Link: http://lkml.kernel.org/r/20170626102058.10200-2-hch@lst.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 block/blk-mq-cpumap.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/block/blk-mq-cpumap.c
+++ b/block/blk-mq-cpumap.c
@@ -35,7 +35,6 @@ int blk_mq_map_queues(struct blk_mq_tag_
 {
 	unsigned int *map = set->mq_map;
 	unsigned int nr_queues = set->nr_hw_queues;
-	const struct cpumask *online_mask = cpu_online_mask;
 	unsigned int i, nr_cpus, nr_uniq_cpus, queue, first_sibling;
 	cpumask_var_t cpus;
 
@@ -44,7 +43,7 @@ int blk_mq_map_queues(struct blk_mq_tag_
 
 	cpumask_clear(cpus);
 	nr_cpus = nr_uniq_cpus = 0;
-	for_each_cpu(i, online_mask) {
+	for_each_present_cpu(i) {
 		nr_cpus++;
 		first_sibling = get_first_sibling(i);
 		if (!cpumask_test_cpu(first_sibling, cpus))
@@ -54,7 +53,7 @@ int blk_mq_map_queues(struct blk_mq_tag_
 
 	queue = 0;
 	for_each_possible_cpu(i) {
-		if (!cpumask_test_cpu(i, online_mask)) {
+		if (!cpumask_test_cpu(i, cpu_present_mask)) {
 			map[i] = 0;
 			continue;
 		}


Patches currently in stable-queue which might be from hch@lst.de are

queue-4.9/blk-mq-include-all-present-cpus-in-the-default-queue-mapping.patch

Re: Patch "blk-mq: Include all present CPUs in the default queue mapping" has been added to the 4.9-stable tree

[Greg KH]

On Tue, Aug 08, 2017 at 10:46:07AM -0700, gregkh@linuxfoundation.org wrote:
> 
> This is a note to let you know that I've just added the patch titled
> 
>     blk-mq: Include all present CPUs in the default queue mapping
> 
> to the 4.9-stable tree which can be found at:
>     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
> 
> The filename of the patch is:
>      blk-mq-include-all-present-cpus-in-the-default-queue-mapping.patch
> and it can be found in the queue-4.9 subdirectory.
> 
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable@vger.kernel.org> know about it.

Nah, I'm dropping this from 4.9, doesn't make sense there at the moment.

thanks,

greg k-h

Re: Patch "blk-mq: Include all present CPUs in the default queue mapping" has been added to the 4.9-stable tree

[Jens Axboe]

On 08/08/2017 12:36 PM, Greg KH wrote:
> On Tue, Aug 08, 2017 at 10:46:07AM -0700, gregkh@linuxfoundation.org wrote:
>>
>> This is a note to let you know that I've just added the patch titled
>>
>>     blk-mq: Include all present CPUs in the default queue mapping
>>
>> to the 4.9-stable tree which can be found at:
>>     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
>>
>> The filename of the patch is:
>>      blk-mq-include-all-present-cpus-in-the-default-queue-mapping.patch
>> and it can be found in the queue-4.9 subdirectory.
>>
>> If you, or anyone else, feels it should not be added to the stable tree,
>> please let <stable@vger.kernel.org> know about it.
> 
> Nah, I'm dropping this from 4.9, doesn't make sense there at the moment.

Yeah, I'd feel much better if we just kept those patches are 4.12.

-- 
Jens Axboe