Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965281AbcKNWXZ (ORCPT ); Mon, 14 Nov 2016 17:23:25 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:33914 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S965117AbcKNWW2 (ORCPT ); Mon, 14 Nov 2016 17:22:28 -0500 From: Shaohua Li To: , CC: , , , Subject: [PATCH V4 14/15] blk-throttle: add interface for per-cgroup target latency Date: Mon, 14 Nov 2016 14:22:21 -0800 Message-ID: <93c7f38eb0d18995cd4d743cb15d986190e5f750.1479161136.git.shli@fb.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: References: X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-11-14_13:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2565 Lines: 109 Add interface for per-cgroup target latency. This latency is for 4k request. Signed-off-by: Shaohua Li --- block/blk-throttle.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index a05d351..ac4d9ea 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -147,6 +147,8 @@ struct throtl_grp { unsigned long last_check_time; int upgrade_check_batch; + + u64 latency_target; /* When did we start a new slice */ unsigned long slice_start[2]; unsigned long slice_end[2]; @@ -463,6 +465,7 @@ static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node) tg->iops[rw][index] = -1; } } + /* target latency default 0, eg, always not meet */ return &tg->pd; } @@ -1572,6 +1575,64 @@ static ssize_t tg_set_limit(struct kernfs_open_file *of, return ret ?: nbytes; } +static u64 tg_prfill_latency_target(struct seq_file *sf, + struct blkg_policy_data *pd, int off) +{ + struct throtl_grp *tg = pd_to_tg(pd); + const char *dname = blkg_dev_name(pd->blkg); + + if (!dname) + return 0; + if (tg->latency_target == 0) + return 0; + + seq_printf(sf, "%s 4k_lat=%llu\n", dname, tg->latency_target); + return 0; +} + +static int tg_print_latency_target(struct seq_file *sf, void *v) +{ + blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), + tg_prfill_latency_target, &blkcg_policy_throtl, + seq_cft(sf)->private, false); + return 0; +} + +static ssize_t tg_set_latency_target(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct blkcg *blkcg = css_to_blkcg(of_css(of)); + struct blkg_conf_ctx ctx; + struct throtl_grp *tg; + int ret = -EINVAL; + char tok[27]; + char *p; + u64 val; + + ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx); + if (ret) + return ret; + + tg = blkg_to_tg(ctx.blkg); + + if (sscanf(ctx.body, "%26s", tok) != 1) + goto out_finish; + + p = tok; + strsep(&p, "="); + if (!p || kstrtou64(p, 10, &val)) + goto out_finish; + + if (strcmp(tok, "4k_lat")) + goto out_finish; + + tg->latency_target = val; + ret = 0; +out_finish: + blkg_conf_finish(&ctx); + return ret ?: nbytes; +} + static struct cftype throtl_files[] = { { .name = "high", @@ -1587,6 +1648,12 @@ static struct cftype throtl_files[] = { .write = tg_set_limit, .private = LIMIT_MAX, }, + { + .name = "latency_target", + .flags = CFTYPE_NOT_ON_ROOT, + .seq_show = tg_print_latency_target, + .write = tg_set_latency_target, + }, { } /* terminate */ }; -- 2.9.3