From: sagi@grimberg.me (Sagi Grimberg)
Subject: Why NVMe MSIx vectors affinity set across NUMA nodes?
Date: Wed, 24 Jan 2018 21:39:02 +0200 [thread overview]
Message-ID: <00b6171e-bc74-9123-a132-14e56f9133dd@grimberg.me> (raw)
In-Reply-To: <20180124154841.GC14790@localhost.localdomain>
>> application uses libnuma to align to numa locality.
>> here the driver is breaking the affinity.
>> certainly having affinity with remote node cpu will add latency to
>> interrupt response time.
>> here it is for some NVMe queues.
>
> I bet you can't come up with an IRQ CPU affinity map that performs better
> than the current setup.
:)
While I agree that managed affinity will probably get the optimal
affinitization in 99% of the cases, this is the second complaint we've
had that managed affinity breaks an existing user interface (even though
it was a sure way to allow userspace to screw up for years).
My mlx5 conversion ended up reverted due to that...
next prev parent reply other threads:[~2018-01-24 19:39 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-22 4:25 Why NVMe MSIx vectors affinity set across NUMA nodes? Ganapatrao Kulkarni
2018-01-22 17:14 ` Keith Busch
2018-01-22 17:22 ` Ganapatrao Kulkarni
2018-01-22 17:32 ` Keith Busch
2018-01-22 17:55 ` Ganapatrao Kulkarni
2018-01-22 18:05 ` Keith Busch
2018-01-22 18:12 ` Ganapatrao Kulkarni
2018-01-22 18:20 ` Keith Busch
2018-01-23 13:30 ` Sagi Grimberg
2018-01-24 2:17 ` Ganapatrao Kulkarni
2018-01-24 15:48 ` Keith Busch
2018-01-24 19:39 ` Sagi Grimberg [this message]
2018-01-24 20:38 ` Keith Busch
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=00b6171e-bc74-9123-a132-14e56f9133dd@grimberg.me \
--to=sagi@grimberg.me \
/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).