From: David Miller <davem@davemloft.net>
To: rahul.lakkireddy@chelsio.com
Cc: netdev@vger.kernel.org, nirranjan@chelsio.com,
vishal@chelsio.com, dt@chelsio.com
Subject: Re: [PATCH net] cxgb4: fix throughput drop during Tx backpressure
Date: Thu, 19 Mar 2020 21:29:50 -0700 (PDT) [thread overview]
Message-ID: <20200319.212950.742799321773945249.davem@davemloft.net> (raw)
In-Reply-To: <1584639490-27208-1-git-send-email-rahul.lakkireddy@chelsio.com>
From: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Date: Thu, 19 Mar 2020 23:08:09 +0530
> commit 7c3bebc3d868 ("cxgb4: request the TX CIDX updates to status page")
> reverted back to getting Tx CIDX updates via DMA, instead of interrupts,
> introduced by commit d429005fdf2c ("cxgb4/cxgb4vf: Add support for SGE
> doorbell queue timer")
>
> However, it missed reverting back several code changes where Tx CIDX
> updates are not explicitly requested during backpressure when using
> interrupt mode. These missed changes cause slow recovery during
> backpressure because the corresponding interrupt no longer comes and
> hence results in Tx throughput drop.
>
> So, revert back these missed code changes, as well, which will allow
> explicitly requesting Tx CIDX updates when backpressure happens.
> This enables the corresponding interrupt with Tx CIDX update message
> to get generated and hence speed up recovery and restore back
> throughput.
>
> Fixes: 7c3bebc3d868 ("cxgb4: request the TX CIDX updates to status page")
> Fixes: d429005fdf2c ("cxgb4/cxgb4vf: Add support for SGE doorbell queue timer")
> Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Applied and queued up for -stable.
prev parent reply other threads:[~2020-03-20 4:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-19 17:38 [PATCH net] cxgb4: fix throughput drop during Tx backpressure Rahul Lakkireddy
2020-03-19 17:38 ` [PATCH net] cxgb4: fix Txq restart check during backpressure Rahul Lakkireddy
2020-03-20 4:30 ` David Miller
2020-03-20 4:29 ` David Miller [this message]
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=20200319.212950.742799321773945249.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=dt@chelsio.com \
--cc=netdev@vger.kernel.org \
--cc=nirranjan@chelsio.com \
--cc=rahul.lakkireddy@chelsio.com \
--cc=vishal@chelsio.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).