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 X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C0EFC28D1E for ; Thu, 6 Jun 2019 10:26:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 68F7F20868 for ; Thu, 6 Jun 2019 10:26:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="K7YLziFU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728368AbfFFK0j (ORCPT ); Thu, 6 Jun 2019 06:26:39 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:55094 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726952AbfFFK0h (ORCPT ); Thu, 6 Jun 2019 06:26:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=+sYPZBeRhiiPR5TRnk5jW3BjnslccP2KlO65GxHb92E=; b=K7YLziFUxdI4VEpmgCeKmJPSIx SmV2eiB6eg2ThrkdcxWsA1EJ8OOD/X5sg3Y4VCEC0Go/8ZSnBC9OP9V34d0itJJjvUNwI6hrabX6L m2A7shwXcZ/4PINojuI0gLH+p9n70AFP6tBHRK0UmS4ECacpHRB02FZNxMQT/ThYqDzyzVUfBk904 ySzoeymaP0c1HdAFbWr/TV5iqw1dVEidw0AbTc+cJ+telg8dm0e5cy4+c0zEx5GHXs33+RJdUVVDq r+nNZXAbjXqixI8rBrBQ0y/+0WD008iGuHW2ChF+JEEbE4MStCrdVkPTPeKVe6VIyuTS3EELlJbht OL8JQ9xw==; Received: from 089144193064.atnat0002.highway.a1.net ([89.144.193.64] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYpbQ-0007hZ-Dh; Thu, 06 Jun 2019 10:26:37 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Paolo Valente , linux-block@vger.kernel.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/6] blk-cgroup: introduce a new struct blkg_rwstat_sample Date: Thu, 6 Jun 2019 12:26:21 +0200 Message-Id: <20190606102624.3847-4-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190606102624.3847-1-hch@lst.de> References: <20190606102624.3847-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When sampling the blkcg counts we don't need atomics or per-cpu variables. Introduce a new structure just containing plain u64 counters. Signed-off-by: Christoph Hellwig --- block/bfq-cgroup.c | 10 ++++------ block/blk-cgroup.c | 39 +++++++++++++++++++------------------- include/linux/blk-cgroup.h | 22 +++++++++++---------- 3 files changed, 35 insertions(+), 36 deletions(-) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 66abc82179f3..624374a99c6e 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -935,7 +935,7 @@ static u64 bfqg_prfill_stat_recursive(struct seq_file *sf, static u64 bfqg_prfill_rwstat_recursive(struct seq_file *sf, struct blkg_policy_data *pd, int off) { - struct blkg_rwstat sum; + struct blkg_rwstat_sample sum; blkg_rwstat_recursive_sum(pd_to_blkg(pd), &blkcg_policy_bfq, off, &sum); return __blkg_prfill_rwstat(sf, pd, &sum); @@ -975,15 +975,13 @@ static int bfqg_print_stat_sectors(struct seq_file *sf, void *v) static u64 bfqg_prfill_sectors_recursive(struct seq_file *sf, struct blkg_policy_data *pd, int off) { - struct blkg_rwstat tmp; - u64 sum; + struct blkg_rwstat_sample tmp; blkg_rwstat_recursive_sum(pd->blkg, NULL, offsetof(struct blkcg_gq, stat_bytes), &tmp); - sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) + - atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]); - return __blkg_prfill_u64(sf, pd, sum >> 9); + return __blkg_prfill_u64(sf, pd, + (tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]) >> 9); } static int bfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 7d6bf9b03e24..aad0f5d9a2ea 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -549,7 +549,7 @@ EXPORT_SYMBOL_GPL(__blkg_prfill_u64); * Print @rwstat to @sf for the device assocaited with @pd. */ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, - const struct blkg_rwstat *rwstat) + const struct blkg_rwstat_sample *rwstat) { static const char *rwstr[] = { [BLKG_RWSTAT_READ] = "Read", @@ -567,12 +567,12 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, for (i = 0; i < BLKG_RWSTAT_NR; i++) seq_printf(sf, "%s %s %llu\n", dname, rwstr[i], - (unsigned long long)atomic64_read(&rwstat->aux_cnt[i])); + rwstat->cnt[i]); - v = atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_READ]) + - atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_WRITE]) + - atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_DISCARD]); - seq_printf(sf, "%s Total %llu\n", dname, (unsigned long long)v); + v = rwstat->cnt[BLKG_RWSTAT_READ] + + rwstat->cnt[BLKG_RWSTAT_WRITE] + + rwstat->cnt[BLKG_RWSTAT_DISCARD]; + seq_printf(sf, "%s Total %llu\n", dname, v); return v; } EXPORT_SYMBOL_GPL(__blkg_prfill_rwstat); @@ -602,7 +602,7 @@ EXPORT_SYMBOL_GPL(blkg_prfill_stat); u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, int off) { - struct blkg_rwstat rwstat = { }; + struct blkg_rwstat_sample rwstat = { }; blkg_rwstat_read((void *)pd + off, &rwstat); return __blkg_prfill_rwstat(sf, pd, &rwstat); @@ -612,7 +612,7 @@ EXPORT_SYMBOL_GPL(blkg_prfill_rwstat); static u64 blkg_prfill_rwstat_field(struct seq_file *sf, struct blkg_policy_data *pd, int off) { - struct blkg_rwstat rwstat = { }; + struct blkg_rwstat_sample rwstat = { }; blkg_rwstat_read((void *)pd->blkg + off, &rwstat); return __blkg_prfill_rwstat(sf, pd, &rwstat); @@ -656,7 +656,7 @@ static u64 blkg_prfill_rwstat_field_recursive(struct seq_file *sf, struct blkg_policy_data *pd, int off) { - struct blkg_rwstat rwstat; + struct blkg_rwstat_sample rwstat; blkg_rwstat_recursive_sum(pd->blkg, NULL, off, &rwstat); return __blkg_prfill_rwstat(sf, pd, &rwstat); @@ -739,7 +739,7 @@ EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum); * @blkg: blkg of interest * @pol: blkcg_policy which contains the blkg_rwstat * @off: offset to the blkg_rwstat in blkg_policy_data or @blkg - * @sum: blkg_rwstat structure containing the results + * @sum: blkg_rwstat_sample structure containing the results * * Collect the blkg_rwstat specified by @blkg, @pol and @off and all its * online descendants and their aux counts. The caller must be holding the @@ -749,7 +749,7 @@ EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum); * is at @off bytes into @blkg's blkg_policy_data of the policy. */ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, - int off, struct blkg_rwstat *sum) + int off, struct blkg_rwstat_sample *sum) { struct blkcg_gq *pos_blkg; struct cgroup_subsys_state *pos_css; @@ -770,8 +770,7 @@ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, rwstat = (void *)pos_blkg + off; for (i = 0; i < BLKG_RWSTAT_NR; i++) - atomic64_set(&sum->aux_cnt[i], - blkg_rwstat_read_counter(rwstat, i)); + sum->cnt[i] = blkg_rwstat_read_counter(rwstat, i); } rcu_read_unlock(); } @@ -939,7 +938,7 @@ 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; + struct blkg_rwstat_sample rwstat; u64 rbytes, wbytes, rios, wios, dbytes, dios; size_t size = seq_get_buf(sf, &buf), off = 0; int i; @@ -961,15 +960,15 @@ static int blkcg_print_stat(struct seq_file *sf, void *v) blkg_rwstat_recursive_sum(blkg, NULL, offsetof(struct blkcg_gq, stat_bytes), &rwstat); - rbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]); - wbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]); - dbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]); + rbytes = rwstat.cnt[BLKG_RWSTAT_READ]; + wbytes = rwstat.cnt[BLKG_RWSTAT_WRITE]; + dbytes = rwstat.cnt[BLKG_RWSTAT_DISCARD]; blkg_rwstat_recursive_sum(blkg, NULL, offsetof(struct blkcg_gq, stat_ios), &rwstat); - rios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]); - wios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]); - dios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]); + rios = rwstat.cnt[BLKG_RWSTAT_READ]; + wios = rwstat.cnt[BLKG_RWSTAT_WRITE]; + dios = rwstat.cnt[BLKG_RWSTAT_DISCARD]; spin_unlock_irq(&blkg->q->queue_lock); diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 3ee858111274..e4a81767e111 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -63,8 +63,7 @@ struct blkcg { /* * blkg_[rw]stat->aux_cnt is excluded for local stats but included for - * recursive. Used to carry stats of dead children, and, for blkg_rwstat, - * to carry result values from read and sum operations. + * recursive. Used to carry stats of dead children. */ struct blkg_stat { struct percpu_counter cpu_cnt; @@ -76,6 +75,10 @@ struct blkg_rwstat { atomic64_t aux_cnt[BLKG_RWSTAT_NR]; }; +struct blkg_rwstat_sample { + u64 cnt[BLKG_RWSTAT_NR]; +}; + /* * A blkcg_gq (blkg) is association between a block cgroup (blkcg) and a * request_queue (q). This is used by blkcg policies which need to track @@ -213,7 +216,7 @@ void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, bool show_total); u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v); u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, - const struct blkg_rwstat *rwstat); + const struct blkg_rwstat_sample *rwstat); u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off); u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd, int off); @@ -225,7 +228,7 @@ int blkg_print_stat_ios_recursive(struct seq_file *sf, void *v); u64 blkg_stat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, int off); void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, - int off, struct blkg_rwstat *sum); + int off, struct blkg_rwstat_sample *sum); struct blkg_conf_ctx { struct gendisk *disk; @@ -701,13 +704,13 @@ static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat, * Read the current snapshot of @rwstat and return it in the aux counts. */ static inline void blkg_rwstat_read(struct blkg_rwstat *rwstat, - struct blkg_rwstat *result) + struct blkg_rwstat_sample *result) { int i; for (i = 0; i < BLKG_RWSTAT_NR; i++) - atomic64_set(&result->aux_cnt[i], - percpu_counter_sum_positive(&rwstat->cpu_cnt[i])); + result->cnt[i] = + percpu_counter_sum_positive(&rwstat->cpu_cnt[i]); } /** @@ -720,11 +723,10 @@ static inline void blkg_rwstat_read(struct blkg_rwstat *rwstat, */ static inline uint64_t blkg_rwstat_total(struct blkg_rwstat *rwstat) { - struct blkg_rwstat tmp = { }; + struct blkg_rwstat_sample tmp = { }; blkg_rwstat_read(rwstat, &tmp); - return atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) + - atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]); + return tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]; } /** -- 2.20.1