From patchwork Tue Sep 1 18:52:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tejun Heo X-Patchwork-Id: 11749393 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7424D1575 for ; Tue, 1 Sep 2020 18:55:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59D49208CA for ; Tue, 1 Sep 2020 18:55:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598986545; bh=QYSUFbBlUZdu0G72XBGzFcXAA/hpWmkZ9H0ZKATRXqc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=m+x4bygvQtdEt8CJdYG4jl656i15q4uHJAuqKDUbyVjWfoVc+qnO7BNWYWW90sdRc gwmISgrBFa1MjG6kRp5r9pjTLa1tKIRVp+rapL+BdX2woSTsach/3aDghe0MjLpJvT zsXMXJBgaIHugYWN3pFmQaDsK9cKbNzpAV42pNGE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731851AbgIASyB (ORCPT ); Tue, 1 Sep 2020 14:54:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57530 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730517AbgIASxv (ORCPT ); Tue, 1 Sep 2020 14:53:51 -0400 Received: from mail-qk1-x741.google.com (mail-qk1-x741.google.com [IPv6:2607:f8b0:4864:20::741]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9FC2C061246; Tue, 1 Sep 2020 11:53:50 -0700 (PDT) Received: by mail-qk1-x741.google.com with SMTP id v69so1993265qkb.7; Tue, 01 Sep 2020 11:53:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=0YDXgIA1K+ZfhGe/lwGuhu8ktkywG9yY1AryQl3mCGI=; b=IJmpZv9OQ33NuZ5oIRloUIYTVC+/7+sFOK4ttwgkljaMn7IlEN3iV9lyqBOcQqR0uC fwmhnl4FPImWoZiBbyHRJG7BhYHTcuwWeuA54PjTv94oC59xUbUSRaXZm0d1u0i0AgYu VFG9TRDpU+0m6LQncYEC0A5mt8TlqhsdiugpoKm41gZCnPKxSRU3IDDOcBMB1NblhHPK GVJnObVjUVwmT6IA68FmGkXSCc2OePwnWp3hj3w6ZBwRNA9cojz8L8AQrQabiMOi6+0q RA6z5tL8/qJ+Ijd6WL/WCnnAezrfV1dSNNTMG500KIQ8kqcLYJREcXLI1md16F1TUv9i gSxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=0YDXgIA1K+ZfhGe/lwGuhu8ktkywG9yY1AryQl3mCGI=; b=IOUBCSTvOoSM/RS9iXykNd6zhPqRjHF7ywUQayi882gw3RlM/uzHT9C1EGUoKLsWqd amCwHrO32bmZx55d6Sqpoci46vvwRO6gGLp3Rl7cYVt5PJfPWVfJTiBhnX6yFYDhGLR2 9DUun0PurkJfQEm6Aivq0j4WOOYXjzaqGgQW6JwoB3DGp6ExV0o9BXBDHdYhR6i3TLAi Fcs9XLhwnPvevTjqhNmIn09DHzVPR8WNkx3ufdzKmq9O9Azj9Hpbti692ERHcOtZtpCb hmhteiTGC3c7rfvG6Gk9mmySn5+GaJe/pGdslMHtKanPQdNF5GJIWWiaR7mcubOmsPyE mwLA== X-Gm-Message-State: AOAM533jNXohMaNCbrRFiEY6988j1bEaS6U+2axc9QfQjtqmKLYGrolx F66c+DJhyYbenHTSDGLbrWI= X-Google-Smtp-Source: ABdhPJzIFXVWPu8lmo/nlLSwxDxGZUx+3Z4piSJAkukXlm2lwWiqEZmkUb/HShPISMCG8nUq8qb7kw== X-Received: by 2002:a37:5042:: with SMTP id e63mr3170231qkb.453.1598986429966; Tue, 01 Sep 2020 11:53:49 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:a198]) by smtp.gmail.com with ESMTPSA id k6sm1865857qti.23.2020.09.01.11.53.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Sep 2020 11:53:49 -0700 (PDT) From: Tejun Heo To: axboe@kernel.dk Cc: linux-block@vger.kernel.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, newella@fb.com, Tejun Heo Subject: [PATCH 15/27] blk-iocost: replace iocg->has_surplus with ->surplus_list Date: Tue, 1 Sep 2020 14:52:45 -0400 Message-Id: <20200901185257.645114-16-tj@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200901185257.645114-1-tj@kernel.org> References: <20200901185257.645114-1-tj@kernel.org> MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Instead of marking iocgs with surplus with a flag and filtering for them while walking all active iocgs, build a surpluses list. This doesn't make much difference now but will help implementing improved donation logic which will iterate iocgs with surplus multiple times. Signed-off-by: Tejun Heo --- block/blk-iocost.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 2496674bbbf4..c1cd66cfa2a8 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -494,9 +494,9 @@ struct ioc_gq { int hweight_gen; u32 hweight_active; u32 hweight_inuse; - bool has_surplus; struct list_head walk_list; + struct list_head surplus_list; struct wait_queue_head waitq; struct hrtimer waitq_timer; @@ -1507,6 +1507,7 @@ static void ioc_timer_fn(struct timer_list *timer) struct ioc *ioc = container_of(timer, struct ioc, timer); struct ioc_gq *iocg, *tiocg; struct ioc_now now; + LIST_HEAD(surpluses); int nr_surpluses = 0, nr_shortages = 0, nr_lagging = 0; u32 ppm_rthr = MILLION - ioc->params.qos[QOS_RPPM]; u32 ppm_wthr = MILLION - ioc->params.qos[QOS_WPPM]; @@ -1630,8 +1631,7 @@ static void ioc_timer_fn(struct timer_list *timer) /* see whether there's surplus vtime */ vmin = now.vnow - ioc->margins.max; - iocg->has_surplus = false; - + WARN_ON_ONCE(!list_empty(&iocg->surplus_list)); if (!waitqueue_active(&iocg->waitq) && time_before64(vtime, vmin)) { u64 delta = vmin - vtime; @@ -1641,7 +1641,7 @@ static void ioc_timer_fn(struct timer_list *timer) atomic64_add(delta, &iocg->done_vtime); /* if usage is sufficiently low, maybe it can donate */ if (surplus_adjusted_hweight_inuse(usage, hw_inuse)) { - iocg->has_surplus = true; + list_add(&iocg->surplus_list, &surpluses); nr_surpluses++; } } else if (hw_inuse < hw_active) { @@ -1677,13 +1677,10 @@ static void ioc_timer_fn(struct timer_list *timer) goto skip_surplus_transfers; /* there are both shortages and surpluses, transfer surpluses */ - list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { + list_for_each_entry(iocg, &surpluses, surplus_list) { u32 usage, hw_active, hw_inuse, new_hwi, new_inuse; int nr_valid = 0; - if (!iocg->has_surplus) - continue; - /* base the decision on max historical usage */ for (i = 0, usage = 0; i < NR_USAGE_SLOTS; i++) { if (iocg->usages[i]) { @@ -1711,6 +1708,10 @@ static void ioc_timer_fn(struct timer_list *timer) skip_surplus_transfers: commit_weights(ioc); + /* surplus list should be dissolved after use */ + list_for_each_entry_safe(iocg, tiocg, &surpluses, surplus_list) + list_del_init(&iocg->surplus_list); + /* * If q is getting clogged or we're missing too much, we're issuing * too much IO and should lower vtime rate. If we're not missing @@ -2284,6 +2285,7 @@ static void ioc_pd_init(struct blkg_policy_data *pd) atomic64_set(&iocg->active_period, atomic64_read(&ioc->cur_period)); INIT_LIST_HEAD(&iocg->active_list); INIT_LIST_HEAD(&iocg->walk_list); + INIT_LIST_HEAD(&iocg->surplus_list); iocg->hweight_active = WEIGHT_ONE; iocg->hweight_inuse = WEIGHT_ONE; @@ -2320,6 +2322,7 @@ static void ioc_pd_free(struct blkg_policy_data *pd) } WARN_ON_ONCE(!list_empty(&iocg->walk_list)); + WARN_ON_ONCE(!list_empty(&iocg->surplus_list)); spin_unlock_irqrestore(&ioc->lock, flags);