All of lore.kernel.org
 help / color / mirror / Atom feed
From: Kuba Piecuch <jpiecuch@google.com>
To: Tejun Heo <tj@kernel.org>
Cc: Kuba Piecuch <jpiecuch@google.com>,
	Andrea Righi <arighi@nvidia.com>,
	 Changwoo Min <changwoo@igalia.com>,
	David Vernet <void@manifault.com>,
	linux-kernel@vger.kernel.org,  sched-ext@lists.linux.dev
Subject: Re: [PATCH sched_ext/for-7.3-fixes] sched_ext: Generate qseq from a per-task counter
Date: Sat,  3 Oct 2026 11:38:38 +0000	[thread overview]
Message-ID: <20261003113843.17313-1-jpiecuch@google.com> (raw)
In-Reply-To: <86a16fc6ea0a57cea7459ac2ebfdfc1b@kernel.org>

Hi Tejun,

On Fri, Oct 02, 2026 at 12:33:27PM -1000, Tejun Heo wrote:
> Maybe wrap the counter where the QSEQ field wraps instead of looping?
>
> 	p->scx.ops_qseq = ((p->scx.ops_qseq + 1) &
> 			   (SCX_OPSS_QSEQ_MASK >> SCX_OPSS_QSEQ_SHIFT)) ?: 1;
> 	qseq = (unsigned long)p->scx.ops_qseq << SCX_OPSS_QSEQ_SHIFT;
>
> On 32bit, the shift drops the top two bits of the counter, so the mask is
> what keeps the counter from reaching a value that shifts to 0.

Sounds good, will send a v2 with this change.

Thanks,
Kuba

      reply	other threads:[~2026-10-03 11:38 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-02 20:52 [PATCH sched_ext/for-7.3-fixes] sched_ext: Generate qseq from a per-task counter Kuba Piecuch
2026-10-02 22:33 ` Tejun Heo
2026-10-03 11:38   ` Kuba Piecuch [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=20261003113843.17313-1-jpiecuch@google.com \
    --to=jpiecuch@google.com \
    --cc=arighi@nvidia.com \
    --cc=changwoo@igalia.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=sched-ext@lists.linux.dev \
    --cc=tj@kernel.org \
    --cc=void@manifault.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.