linux-kernel - Re: [PATCH v3 3/8] sched/topology: Switch to assigning "sd->shared" from 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: <692260d8-d021-4aac-b1ca-28318cbc66d2@amd.com>
Date: Thu, 22 Jan 2026 08:19:57 +0530
From: K Prateek Nayak <kprateek.nayak@....com>
To: "Chen, Yu C" <yu.c.chen@...el.com>
CC: Dietmar Eggemann <dietmar.eggemann@....com>, Steven Rostedt
	<rostedt@...dmis.org>, Ben Segall <bsegall@...gle.com>, Mel Gorman
	<mgorman@...e.de>, Valentin Schneider <vschneid@...hat.com>, Shrikanth Hegde
	<sshegde@...ux.ibm.com>, "Gautham R. Shenoy" <gautham.shenoy@....com>, "Tim
 Chen" <tim.c.chen@...el.com>, <linux-kernel@...r.kernel.org>, Ingo Molnar
	<mingo@...hat.com>, Peter Zijlstra <peterz@...radead.org>, Juri Lelli
	<juri.lelli@...hat.com>, Vincent Guittot <vincent.guittot@...aro.org>
Subject: Re: [PATCH v3 3/8] sched/topology: Switch to assigning "sd->shared"
 from s_data

Hello Chenyu,

On 1/21/2026 8:56 PM, Chen, Yu C wrote:
>> @@ -2655,8 +2655,19 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att
>>           unsigned int imb_span = 1;
>>             for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
>> +            struct sched_domain *parent = sd->parent;
>>               struct sched_domain *child = sd->child;
>>   +            /* Attach sd->shared to the topmost SD_SHARE_LLC domain. */
>> +            if ((sd->flags & SD_SHARE_LLC) &&
>> +                (!parent || !(parent->flags & SD_SHARE_LLC))) {
>> +                int llc_id = cpumask_first(sched_domain_span(sd));
>> +
>> +                sd->shared = *per_cpu_ptr(d.sds, llc_id);
> 
> I agree that in the current implementation, we use the llc_id="first CPU" to
> index into d.sds, and this value actually represents the LLC ID. In the
> cache-aware scheduling, we plan to convert the llc_id to a logical ID that
> is no longer tied to the CPU number. Just 2 cents, to avoid confusion, maybe
> rename the  aforementioned llc_id to sd_id?

Ack! Will modify in the next version!

> 
> Anyway I will run some tests on the entire patch set and provide feedback
> afterward.

Thanks a ton for taking a look at the series! Much appreciated.

-- 
Thanks and Regards,
Prateek