From patchwork Wed Jun 27 19:09:29 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 10492507 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B7F4460325 for ; Wed, 27 Jun 2018 19:14:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C601229DDB for ; Wed, 27 Jun 2018 19:14:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B9E3529E3D; Wed, 27 Jun 2018 19:14:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 581D829DDB for ; Wed, 27 Jun 2018 19:14:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966129AbeF0TOK (ORCPT ); Wed, 27 Jun 2018 15:14:10 -0400 Received: from mail-qk0-f196.google.com ([209.85.220.196]:38564 "EHLO mail-qk0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934930AbeF0TJt (ORCPT ); Wed, 27 Jun 2018 15:09:49 -0400 Received: by mail-qk0-f196.google.com with SMTP id y4-v6so1659979qka.5 for ; Wed, 27 Jun 2018 12:09:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=vfNRWwh46Tv2e1n+AhCODq/AfAwHegq14TUJjZix/bA=; b=u6gYQf+5FRX7tbJBda+cMyyjp/uRagmjjmfkfuiV3fPBdJmkYsGMauYmvqODwMMHlz AIkelcp+QCOR7qrU9muU8l+zR1pvE1kEWkW7ofNrJAHNDvrqgLcR5qEy3XuNQQKI28ml w8FD3xST1L3kbseDl52gExn06Wj7hmRx3/ui/r6LlDl3SIg0JeQ1mOv346KVVle6V0Ww EydkmhkAkTivE/QwPH8nAVS5FcZJ+xntS2TqiHUuIFjma2Gkt69d5WTRvC6EW/mNh6rQ QvSIAxdR7rLHtslW9CtpyiSi5EmAsust3xktBfJkXluYxbEygynMaAmZu3O3hG7Mw1Zk KXPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=vfNRWwh46Tv2e1n+AhCODq/AfAwHegq14TUJjZix/bA=; b=gDFZnQTv7qlRs4KEGyca95Myf1GzIFL5x+OyQyuZ7+KOgZurx05exO4/c6SxmX42WL 8gZk625u/uG49QGtHBHkLkpm84CjwPcOSTAHUyRcAxpFSl58gas312MTsvnyKO+9rweH Zu1otfh1ryp94Pu4q4Pq/4bEaDcQY3ytFqgQCuj1SBVvLztPri3vzFhu5AZP+hgaxh0u 17Q349Z31+3mkeiAthr1fAx1b0YZFeTgZ5d3nk7lw1mCX8hUn63RIYRm/DQwhor9K+Ui p6sxQhEDUt2U39EEgsq/9VfK6WmZVfNLUiTpARB24g095dpV028snrFWUtg13hWQJXJr fh/Q== X-Gm-Message-State: APt69E2/bLCLaKufMzwBg4PiTWJ75xEM2GlFG17nberE/qYLJd78SjSg xWGxDuzsAROXTwJR38HqjiEJSQ== X-Google-Smtp-Source: AAOMgpc6OyrmgsthDGkGpVr5ciY1CByEZKhvo5cLwdLwVlrvfv28IJYvn/OFCA2oC27llCgubIoLvQ== X-Received: by 2002:a37:a316:: with SMTP id m22-v6mr6018997qke.57.1530126588293; Wed, 27 Jun 2018 12:09:48 -0700 (PDT) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id m128-v6sm3065932qkd.33.2018.06.27.12.09.47 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 27 Jun 2018 12:09:47 -0700 (PDT) From: Josef Bacik To: axboe@kernel.dk, linux-block@vger.kernel.org, kernel-team@fb.com, akpm@linux-foundation.org, hannes@cmpxchg.org, tj@kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: Josef Bacik Subject: [PATCH 03/14] blk-cgroup: allow controllers to output their own stats Date: Wed, 27 Jun 2018 15:09:29 -0400 Message-Id: <20180627190940.4696-4-josef@toxicpanda.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180627190940.4696-1-josef@toxicpanda.com> References: <20180627190940.4696-1-josef@toxicpanda.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Josef Bacik blk-iolatency has a few stats that it would like to print out, and instead of adding a bunch of crap to the generic code just provide a helper so that controllers can add stuff to the stat line if they want to. Hide it behind a boot option since it changes the output of io.stat from normal, and these stats are only interesting to developers. Signed-off-by: Josef Bacik --- block/blk-cgroup.c | 49 +++++++++++++++++++++++++++++++++++++++++++--- include/linux/blk-cgroup.h | 3 +++ 2 files changed, 49 insertions(+), 3 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index eb85cb87c40f..b3460f623fca 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -50,6 +50,8 @@ static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS]; static LIST_HEAD(all_blkcgs); /* protected by blkcg_pol_mutex */ +static bool blkcg_debug_stats = false; + static bool blkcg_policy_enabled(struct request_queue *q, const struct blkcg_policy *pol) { @@ -954,13 +956,25 @@ static int blkcg_print_stat(struct seq_file *sf, void *v) hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) { const char *dname; + char *buf; struct blkg_rwstat rwstat; u64 rbytes, wbytes, rios, wios; + size_t size = seq_get_buf(sf, &buf), off = 0; + int i; + bool has_stats = false; dname = blkg_dev_name(blkg); if (!dname) continue; + /* + * Hooray string manipulation, count is the size written NOT + * INCLUDING THE \0, so size is now count+1 less than what we + * had before, but we want to start writing the next bit from + * the \0 so we only add count to buf. + */ + off += scnprintf(buf+off, size-off, "%s ", dname); + spin_lock_irq(blkg->q->queue_lock); rwstat = blkg_rwstat_recursive_sum(blkg, NULL, @@ -975,9 +989,35 @@ static int blkcg_print_stat(struct seq_file *sf, void *v) spin_unlock_irq(blkg->q->queue_lock); - if (rbytes || wbytes || rios || wios) - seq_printf(sf, "%s rbytes=%llu wbytes=%llu rios=%llu wios=%llu\n", - dname, rbytes, wbytes, rios, wios); + if (rbytes || wbytes || rios || wios) { + has_stats = true; + off += scnprintf(buf+off, size-off, + "rbytes=%llu wbytes=%llu rios=%llu wios=%llu", + rbytes, wbytes, rios, wios); + } + + if (!blkcg_debug_stats) + goto next; + + mutex_lock(&blkcg_pol_mutex); + for (i = 0; i < BLKCG_MAX_POLS; i++) { + struct blkcg_policy *pol = blkcg_policy[i]; + size_t written; + + if (!blkg->pd[i] || !pol->pd_stat_fn) + continue; + + written = pol->pd_stat_fn(blkg->pd[i], buf+off, size-off); + if (written) + has_stats = true; + off += written; + } + mutex_unlock(&blkcg_pol_mutex); +next: + if (has_stats) { + off += scnprintf(buf+off, size-off, "\n"); + seq_commit(sf, off); + } } rcu_read_unlock(); @@ -1547,3 +1587,6 @@ void blkcg_policy_unregister(struct blkcg_policy *pol) mutex_unlock(&blkcg_pol_register_mutex); } EXPORT_SYMBOL_GPL(blkcg_policy_unregister); + +module_param(blkcg_debug_stats, bool, 0644); +MODULE_PARM_DESC(blkcg_debug_stats, "True if you want debug stats, false if not"); diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 69aa71dc0c04..b41292726c0f 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -148,6 +148,8 @@ typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd); typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd); typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd); typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd); +typedef size_t (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd, char *buf, + size_t size); struct blkcg_policy { int plid; @@ -167,6 +169,7 @@ struct blkcg_policy { blkcg_pol_offline_pd_fn *pd_offline_fn; blkcg_pol_free_pd_fn *pd_free_fn; blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn; + blkcg_pol_stat_pd_fn *pd_stat_fn; }; extern struct blkcg blkcg_root;