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From: Peter Zijlstra <peterz@infradead.org>
To: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Jean-Baptiste Roquefere <jb.roquefere@ateme.com>,
	"mingo@kernel.org" <mingo@kernel.org>,
	Juri Lelli <juri.lelli@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Borislav Petkov <bp@alien8.de>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
	"Gautham R. Shenoy" <gautham.shenoy@amd.com>,
	Swapnil Sapkal <swapnil.sapkal@amd.com>,
	Valentin Schneider <vschneid@redhat.com>,
	"regressions@lists.linux.dev" <regressions@lists.linux.dev>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: IPC drop down on AMD epyc 7702P
Date: Wed, 30 Apr 2025 11:25:16 +0200	[thread overview]
Message-ID: <20250430092516.GJ4439@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <3daac950-3656-4ec4-bbee-7a3bbad6d631@amd.com>

On Wed, Apr 30, 2025 at 02:43:00PM +0530, K Prateek Nayak wrote:
> (+ more scheduler folks)
> 
> tl;dr
> 
> JB has a workload that hates aggressive migration on the 2nd Generation
> EPYC platform that has a small LLC domain (4C/8T) and very noticeable
> C2C latency.

Seems like the kind of chip the cache aware scheduling crud should be
good for. Of course, it's still early days on that, so it might not be
in good enough shape to help yet.

But long term, that should definitely be the goal, rather than finding
ways to make relax_domain hacks available again.



  reply	other threads:[~2025-04-30  9:25 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-17 21:08 IPC drop down on AMD epyc 7702P Jean-Baptiste Roquefere
2025-04-18  6:39 ` K Prateek Nayak
2025-04-28  7:43   ` Jean-Baptiste Roquefere
2025-04-30  9:13     ` K Prateek Nayak
2025-04-30  9:25       ` Peter Zijlstra [this message]
2025-04-30 10:41       ` Libo Chen
2025-04-30 11:29         ` K Prateek Nayak
2025-05-01  2:46           ` Libo Chen
2025-05-05 10:28       ` Vincent Guittot
2025-05-05 12:29         ` K Prateek Nayak
2025-05-05 15:10           ` Vincent Guittot
2025-05-05 15:16             ` K Prateek Nayak
2025-05-16 15:05               ` Jean-Baptiste Roquefere
2025-05-22 14:51                 ` Vincent Guittot
2025-05-23 12:24                   ` Jean-Baptiste Roquefere
2025-05-26  7:53                     ` Vincent Guittot

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