From: John Garry <john.garry@huawei.com>
To: Sumit Saxena <sumit.saxena@broadcom.com>, Hannes Reinecke <hare@suse.de>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>,
James Bottomley <james.bottomley@hansenpartnership.com>,
Ming Lei <ming.lei@redhat.com>,
Linux SCSI List <linux-scsi@vger.kernel.org>,
<linux-block@vger.kernel.org>, Hannes Reinecke <hare@suse.com>
Subject: Re: [PATCH 09/11] megaraid_sas: switch fusion adapters to MQ
Date: Mon, 13 Jan 2020 17:42:20 +0000 [thread overview]
Message-ID: <11034edd-732a-3dd5-0bdc-891b9de05e56@huawei.com> (raw)
In-Reply-To: <CAL2rwxotoWakFS4DPe85hZ4VAgd_zw8pL+B5ckHR9NwEf+-L=g@mail.gmail.com>
On 10/01/2020 04:00, Sumit Saxena wrote:
> On Mon, Dec 9, 2019 at 4:32 PM Hannes Reinecke <hare@suse.de> wrote:
>>
>> On 12/9/19 11:10 AM, Sumit Saxena wrote:
>>> On Mon, Dec 2, 2019 at 9:09 PM Hannes Reinecke <hare@suse.de> wrote:
>>>>
>>>> Fusion adapters can steer completions to individual queues, and
>>>> we now have support for shared host-wide tags.
>>>> So we can enable multiqueue support for fusion adapters and
>>>> drop the hand-crafted interrupt affinity settings.
>>>
>>> Hi Hannes,
>>>
>>> Ming Lei also proposed similar changes in megaraid_sas driver some
>>> time back and it had resulted in performance drop-
>>> https://patchwork.kernel.org/patch/10969511/
>>>
>>> So, we will do some performance tests with this patch and update you.
>>> Thank you.
>>
>> I'm aware of the results of Ming Leis work, but I do hope this patchset
>> performs better.
>>
>> And when you do performance measurements, can you please run with both,
>> 'none' I/O scheduler and 'mq-deadline' I/O scheduler?
>> I've measured quite a performance improvements when using mq-deadline,
>> up to the point where I've gotten on-par performance with the original,
>> non-mq, implementation.
>> (As a data point, on my setup I've measured about 270k IOPS and 1092
>> MB/s througput, running on just 2 SSDs).
>>asas_build_ldio_fusion
>> But thanks for doing a performance test here.
>
> Hi Hannes,
>
> Sorry for the delay in replying, I observed a few issues with this patchset:
>
> 1. "blk_mq_unique_tag_to_hwq(tag)" does not return MSI-x vector to
> which IO submitter CPU is affined with. Due to this IO submission and
> completion CPUs are different which causes performance drop for low
> latency workloads.
Hi Sumit,
So the new code has:
megasas_build_ldio_fusion()
{
cmd->request_desc->SCSIIO.MSIxIndex =
blk_mq_unique_tag_to_hwq(tag);
}
So the value here is hw queue index from blk-mq point of view, and not
megaraid_sas msix index, as you alluded to.
So we get 80 msix, 8 are reserved for low_latency_index_start (that's
how it seems to me), and we report other 72 as #hw queues = 72 to SCSI
midlayer.
So I think that this should be:
cmd->request_desc->SCSIIO.MSIxIndex =
blk_mq_unique_tag_to_hwq(tag) + low_latency_index_start;
>
> lspcu:
>
> # lscpu
> Architecture: x86_64
> CPU op-mode(s): 32-bit, 64-bit
> Byte Order: Little Endian
> CPU(s): 72
> On-line CPU(s) list: 0-71
> Thread(s) per core: 2
> Core(s) per socket: 18
> Socket(s): 2
> NUMA node(s): 2
> Vendor ID: GenuineIntel
> CPU family: 6
> Model: 85
> Model name: Intel(R) Xeon(R) Gold 6150 CPU @ 2.70GHz
> Stepping: 4
> CPU MHz: 3204.246
> CPU max MHz: 3700.0000
> CPU min MHz: 1200.0000
> BogoMIPS: 5400.00
> Virtualization: VT-x
> L1d cache: 32K
> L1i cache: 32K
> L2 cache: 1024K
> L3 cache: 25344K
> NUMA node0 CPU(s): 0-17,36-53
> NUMA node1 CPU(s): 18-35,54-71
> Flags: fpu vme de pse tsc msr pae mce cx8 apic sep
> mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht
> tm pbe s
> yscall nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts
> rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq
> dtes64 monitor
> ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid dca sse4_1
> sse4_2 x2apic movbe popcnt tsc_deadline_timer xsave avx f16c rdrand
> lahf_lm abm
> 3dnowprefetch cpuid_fault epb cat_l3 cdp_l3 invpcid_single intel_ppin
> mba tpr_shadow vnmi flexpriority ept vpid ept_ad fsgsbase tsc_adjust
> bmi1 hle
> avx2 smep bmi2 erms invpcid rtm cqm mpx rdt_a avx512f avx512dq rdseed
> adx smap clflushopt clwb intel_pt avx512cd avx512bw avx512vl xsaveopt
> xsavec
> xgetbv1 xsaves cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_lo
>
>
[snip]
> 4. This patch removes below code from driver so what this piece of
> code does is broken-
>
>
> - if (instance->adapter_type >= INVADER_SERIES &&
> - !instance->msix_combined) {
> - instance->msix_load_balance = true;
> - instance->smp_affinity_enable = false;
> - }
Does this code need to be re-added? Would this have affected your test?
Thanks,
John
next prev parent reply other threads:[~2020-01-13 17:42 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-02 15:39 [PATCH RFC v5 00/11] blk-mq/scsi: Provide hostwide shared tags for SCSI HBAs Hannes Reinecke
2019-12-02 15:39 ` [PATCH 01/11] blk-mq: Remove some unused function arguments Hannes Reinecke
2019-12-02 15:39 ` [PATCH 02/11] blk-mq: rename BLK_MQ_F_TAG_SHARED as BLK_MQ_F_TAG_QUEUE_SHARED Hannes Reinecke
2019-12-02 15:39 ` [PATCH 03/11] blk-mq: rename blk_mq_update_tag_set_depth() Hannes Reinecke
2019-12-03 14:30 ` John Garry
2019-12-03 14:53 ` Hannes Reinecke
2019-12-02 15:39 ` [PATCH 04/11] blk-mq: Facilitate a shared sbitmap per tagset Hannes Reinecke
2019-12-03 14:54 ` John Garry
2019-12-03 15:02 ` Hannes Reinecke
2019-12-04 10:24 ` John Garry
2019-12-03 16:38 ` Bart Van Assche
2019-12-02 15:39 ` [PATCH 05/11] blk-mq: add WARN_ON in blk_mq_free_rqs() Hannes Reinecke
2019-12-02 15:39 ` [PATCH 06/11] blk-mq: move shared sbitmap into elevator queue Hannes Reinecke
2019-12-02 15:39 ` [PATCH 07/11] scsi: Add template flag 'host_tagset' Hannes Reinecke
2019-12-02 15:39 ` [PATCH 08/11] scsi: hisi_sas: Switch v3 hw to MQ Hannes Reinecke
2019-12-02 15:39 ` [PATCH 09/11] megaraid_sas: switch fusion adapters " Hannes Reinecke
2019-12-09 10:10 ` Sumit Saxena
2019-12-09 11:02 ` Hannes Reinecke
2020-01-10 4:00 ` Sumit Saxena
2020-01-10 12:18 ` John Garry
2020-01-13 17:42 ` John Garry [this message]
2020-01-14 7:05 ` Hannes Reinecke
2020-01-16 15:47 ` John Garry
2020-01-16 17:45 ` Hannes Reinecke
2020-01-17 11:40 ` Sumit Saxena
2020-01-17 11:18 ` Sumit Saxena
2020-02-13 10:07 ` John Garry
2020-02-17 10:09 ` Sumit Saxena
2020-01-09 11:55 ` John Garry
2020-01-09 15:19 ` Hannes Reinecke
2020-01-09 18:17 ` John Garry
2020-01-10 2:00 ` Ming Lei
2020-01-10 12:09 ` John Garry
2020-01-14 13:57 ` John Garry
2019-12-02 15:39 ` [PATCH 10/11] smartpqi: enable host tagset Hannes Reinecke
2019-12-02 15:39 ` [PATCH 11/11] hpsa: enable host_tagset and switch to MQ Hannes Reinecke
2020-02-26 11:09 ` [PATCH RFC v5 00/11] blk-mq/scsi: Provide hostwide shared tags for SCSI HBAs John Garry
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=11034edd-732a-3dd5-0bdc-891b9de05e56@huawei.com \
--to=john.garry@huawei.com \
--cc=axboe@kernel.dk \
--cc=hare@suse.com \
--cc=hare@suse.de \
--cc=hch@lst.de \
--cc=james.bottomley@hansenpartnership.com \
--cc=linux-block@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=martin.petersen@oracle.com \
--cc=ming.lei@redhat.com \
--cc=sumit.saxena@broadcom.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).