From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal =?utf-8?Q?Koutn=C3=BD?= Subject: Re: [PATCH v12 6/8] sched/fair: Add sched group latency support Date: Mon, 27 Feb 2023 15:42:36 +0100 Message-ID: <20230227144236.z6zbgsaohlz6sl7o@blackpad> References: <20230224093454.956298-1-vincent.guittot@linaro.org> <20230224093454.956298-7-vincent.guittot@linaro.org> <20230224192919.d4fcde3dwh7betvm@blackpad> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="k2vtvr4lfwegj6vr" Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1677508958; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=BdizNH1AzSr0bKpBzNhArg9yFjow/CCwchYkew7eG8k=; b=pqUg/q6/MUBr1HnwOq2Z4zkg0ZwcBEX7c8zJkoNMfAMDc0o/YbFfh96lMqOWYqoEOxCR/n xhGpnCZTnjAKDQ+QzC6+DypAo39hvZx0yCFYWJluxJBpy3aoDSq97ScBF2XM4x137ishdq V9PWkJY+8PpVVO8KBzrfuCd9ivVQt7I= Content-Disposition: inline In-Reply-To: List-ID: To: Vincent Guittot Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, linux-kernel@vger.kernel.org, parth@linux.ibm.com, tj@kernel.org, lizefan.x@bytedance.com, hannes@cmpxchg.org, cgroups@vger.kernel.org, corbet@lwn.net, linux-doc@vger.kernel.org, qyousef@layalina.io, chris.hyser@oracle.com, patrick.bellasi@matbug.net, David.Laight@aculab.com, pjt@google.com, pavel@ucw.cz, qperret@google.com, tim.c.chen@linux.intel.com, joshdon@google.com, timj@gnu.org, kprateek.nayak@amd.com, yu.c.chen@intel.com, youssefesmat@chromium.org, joel@joelfernandes.org --k2vtvr4lfwegj6vr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Feb 27, 2023 at 02:44:22PM +0100, Vincent Guittot wrote: > Regarding the current use of latency nice to set a latency offset, the > problem doesn't appear because latency offset applies between entities > at the same level as you mentioned above Splendid, it turned out that way (latency nice analogous to bandwidth nice). > Does my explanation above make sense to you ? Yes, thank you. Thus, I'd like to propose avoiding the use of "limit" in this context and stress the horizontal scope. For example: > + This interface file allows reading and setting latency using the > + same values used by sched_setattr(2). The latency_nice of a group is > + used to limit the impact of the latency_nice of a task outside the > + group. + This interface file allows reading and setting latency using the + same values used by sched_setattr(2). The latency_nice of a group is + used to modify group members' latency with respect to sibling groups. Regards, Michal --k2vtvr4lfwegj6vr Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTrXXag4J0QvXXBmkMkDQmsBEOquQUCY/zBWgAKCRAkDQmsBEOq uRXXAP4nBfg1JWkFJlUphJU/HXYaqG7HKuwUDehUmhtQOcLnRQD/XqLftrr1aayr WcfeRCiKVdubEZX6L35zYCrcNd3hBAM= =FRsw -----END PGP SIGNATURE----- --k2vtvr4lfwegj6vr--