linux-kernel - Re: [PATCH v3 2/8] sched/topology: Allocate per-CPU sched_domain_shared in s

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <xhsmh8qd73zex.mognet@vschneid-thinkpadt14sgen2i.remote.csb>
Date: Thu, 05 Feb 2026 17:53:10 +0100
From: Valentin Schneider <vschneid@...hat.com>
To: K Prateek Nayak <kprateek.nayak@....com>, Ingo Molnar
 <mingo@...hat.com>, Peter Zijlstra <peterz@...radead.org>, Juri Lelli
 <juri.lelli@...hat.com>, Vincent Guittot <vincent.guittot@...aro.org>,
 linux-kernel@...r.kernel.org
Cc: Dietmar Eggemann <dietmar.eggemann@....com>, Steven Rostedt
 <rostedt@...dmis.org>, Ben Segall <bsegall@...gle.com>, Mel Gorman
 <mgorman@...e.de>, Chen Yu <yu.c.chen@...el.com>, Shrikanth Hegde
 <sshegde@...ux.ibm.com>, "Gautham R.
 Shenoy" <gautham.shenoy@....com>, K Prateek Nayak <kprateek.nayak@....com>
Subject: Re: [PATCH v3 2/8] sched/topology: Allocate per-CPU
 sched_domain_shared in s_data

On 20/01/26 11:32, K Prateek Nayak wrote:
> The "sched_domain_shared" object is allocated for every topology level
> in __sdt_alloc() and is freed post sched domain rebuild if they aren't
> assigned during sd_init().
>
> "sd->shared" is only assigned for SD_SHARE_LLC domains and out of all
> the assigned objects, only "sd_llc_shared" is ever used by the
> scheduler.
>
> Since only "sd_llc_shared" is ever used, and since SD_SHARE_LLC domains
> never overlap, allocate only a single range of per-CPU
> "sched_domain_shared" object with s_data instead of doing it per
> topology level.
>
> The subsequent commit uses the degeneration path to correctly assign the
> "sd->shared" to the topmost SD_SHARE_LLC domain.
>
> No functional changes are expected at this point.
>
> Signed-off-by: K Prateek Nayak <kprateek.nayak@....com>

Reviewed-by: Valentin Schneider <vschneid@...hat.com>