From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60733C7EE22 for ; Sun, 14 May 2023 16:34:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231804AbjENQdw (ORCPT ); Sun, 14 May 2023 12:33:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229585AbjENQds (ORCPT ); Sun, 14 May 2023 12:33:48 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 935951FD3 for ; Sun, 14 May 2023 09:33:44 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-ba712bb7b28so14117919276.1 for ; Sun, 14 May 2023 09:33:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1684082024; x=1686674024; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=cW39sCOiQuWUDDt62jwZLbPEO+MK1W7Jssj7ZgBQQzA=; b=nWZpfeKT1vKKVo/0MbH6ZGjWOcPjpzlEU39owpBlVnzPz/PCiAaymVhSTV1gOgUNV1 xG7WUhJchN4HE8BcHbS9HFlcfFS6bDN6SKkVvPkiEZrQcIV7o4AkTMNZfLrX2WRbX0+t ioPXjZH9AFWtxK1ZjU+YJOYwnrGRTgw1kWItNH4eD3KcgtEuEvxdsVrp2EHcA29Hle5K AkuCQmrJ6o/75muTuaBWhvf6Oh+KgU2sdIoIxA3NEjvtkiILkTC+86oT51asLhuKjJof MiL7BlVQmBNlxVsFOV9ABR6Woqhp8Hphsn3PWQhyQY4FZ3Ib3TDSYSoCNsJqa6xQPLHj lSYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684082024; x=1686674024; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=cW39sCOiQuWUDDt62jwZLbPEO+MK1W7Jssj7ZgBQQzA=; b=MzlTir/+MMfOC5mcdF5Com9jt+SE+qr09a/41pncZ6jHoeb1nwkvO8HYfdchRUt/cq gsMs2llFMaMzwpoQVwQSbcIHJtmGeddgsWWarH+CvG/8xVP0+Umjf7KzmuixVJc+dn/f 51zKG3Kb89AVoslExziS6nIPH2pbzMGajyZC2TJdd6d1fFOzIUiScvTVhkUZLaSRPxlF KpfE5WpMpqe1mGFqG4drgloMcETs7htrdn2lw20MFBlcp2XU+eBzR/XM+5I4ZvFtl7/Q ZVAvJSdw85JJGsMIdy+O7cNQ3HaUTGljPoU4x7QUFRRfuPBShDrHGbB/iRYpp6LsqYHV GbmA== X-Gm-Message-State: AC+VfDyeXJlFXExhh8qiUZAp97fH4uLZZIMLpk0xEc8JDz1wVuGcSR8h +Nii3+A12zbxr4Uws2kqOUZDR7TLpfY= X-Google-Smtp-Source: ACHHUZ4Vte0svHfW1+s+ohtYvezACgh+0auFBnz6XRVv/3Ufq/3+wM3l0CuZwJRdlFO9Df5CrIDBXt9F28Q= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:201:a90e:968:96d4:175a]) (user=surenb job=sendgmr) by 2002:a05:6902:1610:b0:ba7:8628:93e2 with SMTP id bw16-20020a056902161000b00ba7862893e2mr2248658ybb.4.1684082023857; Sun, 14 May 2023 09:33:43 -0700 (PDT) Date: Sun, 14 May 2023 09:33:38 -0700 Mime-Version: 1.0 X-Mailer: git-send-email 2.40.1.606.ga4b1b128d6-goog Message-ID: <20230514163338.834345-1-surenb@google.com> Subject: [PATCH 1/1] sched/psi: avoid resetting the min update period when it is unnecessary From: Suren Baghdasaryan To: peterz@infradead.org Cc: yang.yang29@zte.com.cn, mingo@redhat.com, axboe@kernel.dk, tj@kernel.org, hannes@cmpxchg.org, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, surenb@google.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yang Yang Psi_group's poll_min_period is determined by the minimum window size of psi_trigger when creating new triggers. While destroying a psi_trigger, there is no need to reset poll_min_period if the psi_trigger being destroyed did not have the minimum window size, since in this condition poll_min_period will remain the same as before. Signed-off-by: Yang Yang Acked-by: Suren Baghdasaryan --- rebase of https://lore.kernel.org/all/202305121642367753446@zte.com.cn/ over git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched/core branch kernel/sched/psi.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index b49af594ad28..81fca77397f6 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -1407,11 +1407,16 @@ void psi_trigger_destroy(struct psi_trigger *t) group->rtpoll_nr_triggers[t->state]--; if (!group->rtpoll_nr_triggers[t->state]) group->rtpoll_states &= ~(1 << t->state); - /* reset min update period for the remaining triggers */ - list_for_each_entry(tmp, &group->rtpoll_triggers, node) - period = min(period, div_u64(tmp->win.size, - UPDATES_PER_WINDOW)); - group->rtpoll_min_period = period; + /* + * Reset min update period for the remaining triggers + * iff the destroying trigger had the min window size. + */ + if (group->rtpoll_min_period == div_u64(t->win.size, UPDATES_PER_WINDOW)) { + list_for_each_entry(tmp, &group->rtpoll_triggers, node) + period = min(period, div_u64(tmp->win.size, + UPDATES_PER_WINDOW)); + group->rtpoll_min_period = period; + } /* Destroy rtpoll_task when the last trigger is destroyed */ if (group->rtpoll_states == 0) { group->rtpoll_until = 0; -- 2.40.1.606.ga4b1b128d6-goog