From patchwork Mon Nov 16 17:23:05 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Moyer X-Patchwork-Id: 7629361 Return-Path: X-Original-To: patchwork-linux-block@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 4F894BF90C for ; Mon, 16 Nov 2015 17:23:13 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 77048204D9 for ; Mon, 16 Nov 2015 17:23:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 509B6204D1 for ; Mon, 16 Nov 2015 17:23:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752532AbbKPRXJ (ORCPT ); Mon, 16 Nov 2015 12:23:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36911 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751265AbbKPRXH (ORCPT ); Mon, 16 Nov 2015 12:23:07 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id 7A57891DCA; Mon, 16 Nov 2015 17:23:07 +0000 (UTC) Received: from segfault.boston.devel.redhat.com (segfault.boston.devel.redhat.com [10.19.60.26]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id tAGHN6xV016757 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 16 Nov 2015 12:23:06 -0500 From: Jeff Moyer To: Jan Kara , Jens Axboe Cc: LKML , linux-block@vger.kernel.org Subject: Re: CFQ timer precision References: <20151116151159.GE3443@quack.suse.cz> <564A0142.2090605@kernel.dk> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Mon, 16 Nov 2015 12:23:05 -0500 In-Reply-To: <564A0142.2090605@kernel.dk> (Jens Axboe's message of "Mon, 16 Nov 2015 09:16:02 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Spam-Status: No, score=-7.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hi Jan, Jens Axboe writes: > On 11/16/2015 08:11 AM, Jan Kara wrote: >> Hello, >> >> lately I was looking into a big performance hit we take when blkio >> controller is enabled and jbd2 thread ends up in a different cgroup than >> user process. E.g. dbench4 throughput drops from ~140 MB/s to ~20 MB/s. >> However artificial dbench4 is, this kind of drop will likely be clearly >> visible in real life workloads as well. With unified cgroup hierarchy >> the above cgroup split between jbd2 and user processes is unavoidable >> once you enable blkio controller so IMO we should accomodate that better. Is group idle enabled? What happens if you set that to 0? What's the storage? >> I have couple of CFQ idling improvements / fixes which I'll post later this >> week once I'll complete some round of benchmarking. They improve the >> throughput to ~40 MB/s which helps but clearly there's still a big room for >> improvement. The reason for the performance drop is essentially in idling >> we do to avoid starvation of CFQ queues. Now when idling in this context, >> current default of 8 ms idle window is far to large - we start the timer >> after the final request is completed and thus we effectively give the >> process 8 ms of CPU time to submit the next IO request. Which I think is >> usually far too much. I think I'd need to see blktrace data to make any real sense of this problem statement. It's just too vague. >> The problem is that more fine grained idling is >> actually problematic because e.g. SUSE distro kernels have HZ=250 and thus >> 1 jiffy is 4 ms. Hence my proposal: Do you think it would be OK to convert >> CFQ to use highres timers and do all the accounting in microseconds? >> Then we could tune the idle time to be say 1ms or even autotune it based on >> process' think time both of which I expect would get us much closer to >> original throughput (4 ms idle window gets us to ~70 MB/s with my patches, >> disabling idling gets us to original throughput as expected). > > Converting to a non-jiffies timer base should be quite fine. We didn't > have hrtimers when CFQ was written :-) I actually have a patch that allows setting slices at the usec granularity, but didn't go so far as to use hrtimers. I have no idea why I wrote it, or whether it works. ;-) I've attached it in case it's useful to you, Jan. Cheers, Jeff --- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 5da8e6e..fc50fa77 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -10,7 +10,7 @@ #include #include #include -#include +#include #include #include #include @@ -22,23 +22,23 @@ */ /* max queue in one round of service */ static const int cfq_quantum = 8; -static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; +static const int cfq_fifo_expire[2] = { NSEC_PER_SEC / 4, NSEC_PER_SEC / 8 }; /* maximum backwards seek, in KiB */ static const int cfq_back_max = 16 * 1024; /* penalty of a backwards seek */ static const int cfq_back_penalty = 2; -static const int cfq_slice_sync = HZ / 10; -static int cfq_slice_async = HZ / 25; +static const int cfq_slice_sync = NSEC_PER_SEC / 10; +static int cfq_slice_async = NSEC_PER_SEC / 25; static const int cfq_slice_async_rq = 2; -static int cfq_slice_idle = HZ / 125; -static int cfq_group_idle = HZ / 125; -static const int cfq_target_latency = HZ * 3/10; /* 300 ms */ +static int cfq_slice_idle = NSEC_PER_SEC / 125; +static int cfq_group_idle = NSEC_PER_SEC / 125; +static const int cfq_target_latency = NSEC_PER_SEC * 3/10; /* 300 ms */ static const int cfq_hist_divisor = 4; /* * offset from end of service tree */ -#define CFQ_IDLE_DELAY (HZ / 5) +#define CFQ_IDLE_DELAY (NSEC_PER_SEC / 5) /* * below this threshold, we consider thinktime immediate @@ -89,7 +89,7 @@ struct cfq_rb_root { struct cfq_ttime ttime; }; #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, \ - .ttime = {.last_end_request = jiffies,},} + .ttime = {.last_end_request = ktime_get_ns(),},} /* * Per process-grouping structure @@ -104,7 +104,7 @@ struct cfq_queue { /* service_tree member */ struct rb_node rb_node; /* service_tree key */ - unsigned long rb_key; + u64 rb_key; /* prio tree member */ struct rb_node p_node; /* prio tree root we belong to, if any */ @@ -125,8 +125,8 @@ struct cfq_queue { unsigned int allocated_slice; unsigned int slice_dispatch; /* time when first request from queue completed and slice started. */ - unsigned long slice_start; - unsigned long slice_end; + u64 slice_start; + u64 slice_end; long slice_resid; /* pending priority requests */ @@ -1046,11 +1046,12 @@ static inline void cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) { unsigned slice = cfq_scaled_cfqq_slice(cfqd, cfqq); + u64 now = ktime_get_ns(); - cfqq->slice_start = jiffies; - cfqq->slice_end = jiffies + slice; + cfqq->slice_start = now; + cfqq->slice_end = now + slice; cfqq->allocated_slice = slice; - cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); + cfq_log_cfqq(cfqd, cfqq, "set_slice=%llu", cfqq->slice_end - now); } /* @@ -1062,7 +1063,7 @@ static inline bool cfq_slice_used(struct cfq_queue *cfqq) { if (cfq_cfqq_slice_new(cfqq)) return false; - if (time_before(jiffies, cfqq->slice_end)) + if (ktime_get_ns() < cfqq->slice_end) return false; return true; @@ -1426,27 +1427,27 @@ static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq, unsigned int *unaccounted_time) { unsigned int slice_used; + u64 now = ktime_get_ns(); /* * Queue got expired before even a single request completed or * got expired immediately after first request completion. */ - if (!cfqq->slice_start || cfqq->slice_start == jiffies) { + if (!cfqq->slice_start || cfqq->slice_start == now) { /* * Also charge the seek time incurred to the group, otherwise * if there are mutiple queues in the group, each can dispatch * a single request on seeky media and cause lots of seek time * and group will never know it. */ - slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start), - 1); + slice_used = max_t(unsigned, (now - cfqq->dispatch_start), 1); } else { - slice_used = jiffies - cfqq->slice_start; + slice_used = now - cfqq->slice_start; if (slice_used > cfqq->allocated_slice) { *unaccounted_time = slice_used - cfqq->allocated_slice; slice_used = cfqq->allocated_slice; } - if (time_after(cfqq->slice_start, cfqq->dispatch_start)) + if (cfqq->slice_start > cfqq->dispatch_start) *unaccounted_time += cfqq->slice_start - cfqq->dispatch_start; } @@ -1462,6 +1463,7 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) - cfqg->service_tree_idle.count; unsigned int vfr; + u64 now = ktime_get_ns(); BUG_ON(nr_sync < 0); used_sl = charge = cfq_cfqq_slice_usage(cfqq, &unaccounted_sl); @@ -1483,9 +1485,8 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, cfq_group_service_tree_add(st, cfqg); /* This group is being expired. Save the context */ - if (time_after(cfqd->workload_expires, jiffies)) { - cfqg->saved_wl_slice = cfqd->workload_expires - - jiffies; + if (cfqd->workload_expires > now) { + cfqg->saved_wl_slice = cfqd->workload_expires - now; cfqg->saved_wl_type = cfqd->serving_wl_type; cfqg->saved_wl_class = cfqd->serving_wl_class; } else @@ -1517,7 +1518,7 @@ static void cfq_init_cfqg_base(struct cfq_group *cfqg) *st = CFQ_RB_ROOT; RB_CLEAR_NODE(&cfqg->rb_node); - cfqg->ttime.last_end_request = jiffies; + cfqg->ttime.last_end_request = ktime_get_ns(); } #ifdef CONFIG_CFQ_GROUP_IOSCHED @@ -2024,10 +2025,11 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, { struct rb_node **p, *parent; struct cfq_queue *__cfqq; - unsigned long rb_key; + u64 rb_key; struct cfq_rb_root *st; int left; int new_cfqq = 1; + u64 now = ktime_get_ns(); st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq)); if (cfq_class_idle(cfqq)) { @@ -2037,7 +2039,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, __cfqq = rb_entry(parent, struct cfq_queue, rb_node); rb_key += __cfqq->rb_key; } else - rb_key += jiffies; + rb_key += now; } else if (!add_front) { /* * Get our rb key offset. Subtract any residual slice @@ -2045,13 +2047,13 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, * count indicates slice overrun, and this should position * the next service time further away in the tree. */ - rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; + rb_key = cfq_slice_offset(cfqd, cfqq) + now; rb_key -= cfqq->slice_resid; cfqq->slice_resid = 0; } else { - rb_key = -HZ; + rb_key = -NSEC_PER_SEC; __cfqq = cfq_rb_first(st); - rb_key += __cfqq ? __cfqq->rb_key : jiffies; + rb_key += __cfqq ? __cfqq->rb_key : now; } if (!RB_EMPTY_NODE(&cfqq->rb_node)) { @@ -2077,7 +2079,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, /* * sort by key, that represents service time. */ - if (time_before(rb_key, __cfqq->rb_key)) + if (rb_key < __cfqq->rb_key) p = &parent->rb_left; else { p = &parent->rb_right; @@ -2377,7 +2379,7 @@ cfq_merged_requests(struct request_queue *q, struct request *rq, * reposition in fifo if next is older than rq */ if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && - time_before(next->fifo_time, rq->fifo_time) && + next->fifo_time < rq->fifo_time && cfqq == RQ_CFQQ(next)) { list_move(&rq->queuelist, &next->queuelist); rq->fifo_time = next->fifo_time; @@ -2438,7 +2440,7 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd, cfqd->serving_wl_class, cfqd->serving_wl_type); cfqg_stats_update_avg_queue_size(cfqq->cfqg); cfqq->slice_start = 0; - cfqq->dispatch_start = jiffies; + cfqq->dispatch_start = ktime_get_ns(); cfqq->allocated_slice = 0; cfqq->slice_end = 0; cfqq->slice_dispatch = 0; @@ -2487,7 +2489,7 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, if (cfq_cfqq_slice_new(cfqq)) cfqq->slice_resid = cfq_scaled_cfqq_slice(cfqd, cfqq); else - cfqq->slice_resid = cfqq->slice_end - jiffies; + cfqq->slice_resid = cfqq->slice_end - ktime_get_ns(); cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); } @@ -2722,6 +2724,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) struct cfq_queue *cfqq = cfqd->active_queue; struct cfq_io_cq *cic; unsigned long sl, group_idle = 0; + u64 now = ktime_get_ns(); /* * SSD device without seek penalty, disable idling. But only do so @@ -2764,7 +2767,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) * time slice. */ if (sample_valid(cic->ttime.ttime_samples) && - (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) { + (cfqq->slice_end - now < cic->ttime.ttime_mean)) { cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%lu", cic->ttime.ttime_mean); return; @@ -2781,7 +2784,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) else sl = cfqd->cfq_slice_idle; - mod_timer(&cfqd->idle_slice_timer, jiffies + sl); + mod_timer(&cfqd->idle_slice_timer, now + sl); cfqg_stats_set_start_idle_time(cfqq->cfqg); cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu group_idle: %d", sl, group_idle ? 1 : 0); @@ -2824,7 +2827,7 @@ static struct request *cfq_check_fifo(struct cfq_queue *cfqq) return NULL; rq = rq_entry_fifo(cfqq->fifo.next); - if (time_before(jiffies, rq->fifo_time)) + if (ktime_get_ns() < rq->fifo_time) rq = NULL; cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); @@ -2909,7 +2912,7 @@ static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd, /* select the one with lowest rb_key */ queue = cfq_rb_first(st_for(cfqg, wl_class, i)); if (queue && - (!key_valid || time_before(queue->rb_key, lowest_key))) { + (!key_valid || queue->rb_key < lowest_key)) { lowest_key = queue->rb_key; cur_best = i; key_valid = true; @@ -2927,6 +2930,7 @@ choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg) struct cfq_rb_root *st; unsigned group_slice; enum wl_class_t original_class = cfqd->serving_wl_class; + u64 now = ktime_get_ns(); /* Choose next priority. RT > BE > IDLE */ if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg)) @@ -2935,7 +2939,7 @@ choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg) cfqd->serving_wl_class = BE_WORKLOAD; else { cfqd->serving_wl_class = IDLE_WORKLOAD; - cfqd->workload_expires = jiffies + 1; + cfqd->workload_expires = now + jiffies_to_nsecs(1); return; } @@ -2953,7 +2957,7 @@ choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg) /* * check workload expiration, and that we still have other queues ready */ - if (count && !time_after(jiffies, cfqd->workload_expires)) + if (count && !(now > cfqd->workload_expires)) return; new_workload: @@ -2999,7 +3003,7 @@ new_workload: slice = max_t(unsigned, slice, CFQ_MIN_TT); cfq_log(cfqd, "workload slice:%d", slice); - cfqd->workload_expires = jiffies + slice; + cfqd->workload_expires = now + slice; } static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) @@ -3017,16 +3021,17 @@ static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) static void cfq_choose_cfqg(struct cfq_data *cfqd) { struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); + u64 now = ktime_get_ns(); cfqd->serving_group = cfqg; /* Restore the workload type data */ if (cfqg->saved_wl_slice) { - cfqd->workload_expires = jiffies + cfqg->saved_wl_slice; + cfqd->workload_expires = now + cfqg->saved_wl_slice; cfqd->serving_wl_type = cfqg->saved_wl_type; cfqd->serving_wl_class = cfqg->saved_wl_class; } else - cfqd->workload_expires = jiffies - 1; + cfqd->workload_expires = now - 1; choose_wl_class_and_type(cfqd, cfqg); } @@ -3038,6 +3043,7 @@ static void cfq_choose_cfqg(struct cfq_data *cfqd) static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) { struct cfq_queue *cfqq, *new_cfqq = NULL; + u64 now = ktime_get_ns(); cfqq = cfqd->active_queue; if (!cfqq) @@ -3109,7 +3115,7 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) **/ if (CFQQ_SEEKY(cfqq) && cfq_cfqq_idle_window(cfqq) && (cfq_cfqq_slice_new(cfqq) || - (cfqq->slice_end - jiffies > jiffies - cfqq->slice_start))) { + (cfqq->slice_end - now > now - cfqq->slice_start))) { cfq_clear_cfqq_deep(cfqq); cfq_clear_cfqq_idle_window(cfqq); } @@ -3187,11 +3193,12 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd) static inline bool cfq_slice_used_soon(struct cfq_data *cfqd, struct cfq_queue *cfqq) { + u64 now = ktime_get_ns(); + /* the queue hasn't finished any request, can't estimate */ if (cfq_cfqq_slice_new(cfqq)) return true; - if (time_after(jiffies + cfqd->cfq_slice_idle * cfqq->dispatched, - cfqq->slice_end)) + if (now + cfqd->cfq_slice_idle * cfqq->dispatched > cfqq->slice_end) return true; return false; @@ -3266,7 +3273,7 @@ static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) * based on the last sync IO we serviced */ if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { - unsigned long last_sync = jiffies - cfqd->last_delayed_sync; + unsigned long last_sync = ktime_get_ns() - cfqd->last_delayed_sync; unsigned int depth; depth = last_sync / cfqd->cfq_slice[1]; @@ -3352,7 +3359,7 @@ static int cfq_dispatch_requests(struct request_queue *q, int force) if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || cfq_class_idle(cfqq))) { - cfqq->slice_end = jiffies + 1; + cfqq->slice_end = ktime_get_ns() + 1; cfq_slice_expired(cfqd, 0); } @@ -3430,7 +3437,7 @@ static void cfq_init_icq(struct io_cq *icq) { struct cfq_io_cq *cic = icq_to_cic(icq); - cic->ttime.last_end_request = jiffies; + cic->ttime.last_end_request = ktime_get_ns(); } static void cfq_exit_icq(struct io_cq *icq) @@ -3694,7 +3701,7 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, static void __cfq_update_io_thinktime(struct cfq_ttime *ttime, unsigned long slice_idle) { - unsigned long elapsed = jiffies - ttime->last_end_request; + unsigned long elapsed = ktime_get_ns() - ttime->last_end_request; elapsed = min(elapsed, 2UL * slice_idle); ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8; @@ -3947,7 +3954,7 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq) cfq_log_cfqq(cfqd, cfqq, "insert_request"); cfq_init_prio_data(cfqq, RQ_CIC(rq)); - rq->fifo_time = jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]; + rq->fifo_time = ktime_get_ns() + cfqd->cfq_fifo_expire[rq_is_sync(rq)]; list_add_tail(&rq->queuelist, &cfqq->fifo); cfq_add_rq_rb(rq); cfqg_stats_update_io_add(RQ_CFQG(rq), cfqd->serving_group, @@ -3995,6 +4002,7 @@ static void cfq_update_hw_tag(struct cfq_data *cfqd) static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) { struct cfq_io_cq *cic = cfqd->active_cic; + u64 now = ktime_get_ns(); /* If the queue already has requests, don't wait */ if (!RB_EMPTY_ROOT(&cfqq->sort_list)) @@ -4013,7 +4021,7 @@ static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) /* if slice left is less than think time, wait busy */ if (cic && sample_valid(cic->ttime.ttime_samples) - && (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) + && (cfqq->slice_end - now < cic->ttime.ttime_mean)) return true; /* @@ -4023,7 +4031,7 @@ static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) * case where think time is less than a jiffy, mark the queue wait * busy if only 1 jiffy is left in the slice. */ - if (cfqq->slice_end - jiffies == 1) + if (cfqq->slice_end - now <= jiffies_to_nsecs(1)) return true; return false; @@ -4034,9 +4042,8 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) struct cfq_queue *cfqq = RQ_CFQQ(rq); struct cfq_data *cfqd = cfqq->cfqd; const int sync = rq_is_sync(rq); - unsigned long now; + u64 now = ktime_get_ns(); - now = jiffies; cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", !!(rq->cmd_flags & REQ_NOIDLE)); @@ -4064,7 +4071,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) cfqq_type(cfqq)); st->ttime.last_end_request = now; - if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now)) + if (!(rq->start_time + cfqd->cfq_fifo_expire[1] > now)) cfqd->last_delayed_sync = now; } @@ -4092,7 +4099,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) unsigned long extend_sl = cfqd->cfq_slice_idle; if (!cfqd->cfq_slice_idle) extend_sl = cfqd->cfq_group_idle; - cfqq->slice_end = jiffies + extend_sl; + cfqq->slice_end = now + extend_sl; cfq_mark_cfqq_wait_busy(cfqq); cfq_log_cfqq(cfqd, cfqq, "will busy wait"); } @@ -4468,7 +4475,7 @@ static int cfq_init_queue(struct request_queue *q, struct elevator_type *e) * we optimistically start assuming sync ops weren't delayed in last * second, in order to have larger depth for async operations. */ - cfqd->last_delayed_sync = jiffies - HZ; + cfqd->last_delayed_sync = ktime_get_ns() - NSEC_PER_SEC; return 0; out_free: @@ -4501,7 +4508,7 @@ static ssize_t __FUNC(struct elevator_queue *e, char *page) \ struct cfq_data *cfqd = e->elevator_data; \ unsigned int __data = __VAR; \ if (__CONV) \ - __data = jiffies_to_msecs(__data); \ + __data = __data / NSEC_PER_MSEC; \ return cfq_var_show(__data, (page)); \ } SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); @@ -4518,6 +4525,20 @@ SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); SHOW_FUNCTION(cfq_target_latency_show, cfqd->cfq_target_latency, 1); #undef SHOW_FUNCTION +#define USEC_SHOW_FUNCTION(__FUNC, __VAR) \ +static ssize_t __FUNC(struct elevator_queue *e, char *page) \ +{ \ + struct cfq_data *cfqd = e->elevator_data; \ + unsigned int __data = __VAR; \ + __data = __data / NSEC_PER_USEC; \ + return cfq_var_show(__data, (page)); \ +} +USEC_SHOW_FUNCTION(cfq_slice_idle_us_show, cfqd->cfq_slice_idle); +USEC_SHOW_FUNCTION(cfq_group_idle_us_show, cfqd->cfq_group_idle); +USEC_SHOW_FUNCTION(cfq_slice_sync_us_show, cfqd->cfq_slice[1]); +USEC_SHOW_FUNCTION(cfq_slice_async_us_show, cfqd->cfq_slice[0]); +#undef USEC_SHOW_FUNCTION + #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ { \ @@ -4529,7 +4550,7 @@ static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) else if (__data > (MAX)) \ __data = (MAX); \ if (__CONV) \ - *(__PTR) = msecs_to_jiffies(__data); \ + *(__PTR) = __data * NSEC_PER_MSEC; \ else \ *(__PTR) = __data; \ return ret; \ @@ -4552,6 +4573,25 @@ STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); STORE_FUNCTION(cfq_target_latency_store, &cfqd->cfq_target_latency, 1, UINT_MAX, 1); #undef STORE_FUNCTION +#define USEC_STORE_FUNCTION(__FUNC, __PTR, MIN, MAX) \ +static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ +{ \ + struct cfq_data *cfqd = e->elevator_data; \ + unsigned int __data; \ + int ret = cfq_var_store(&__data, (page), count); \ + if (__data < (MIN)) \ + __data = (MIN); \ + else if (__data > (MAX)) \ + __data = (MAX); \ + *(__PTR) = __data * NSEC_PER_USEC; \ + return ret; \ +} +USEC_STORE_FUNCTION(cfq_slice_idle_us_store, &cfqd->cfq_slice_idle, 0, UINT_MAX); +USEC_STORE_FUNCTION(cfq_group_idle_us_store, &cfqd->cfq_group_idle, 0, UINT_MAX); +USEC_STORE_FUNCTION(cfq_slice_sync_us_store, &cfqd->cfq_slice[1], 1, UINT_MAX); +USEC_STORE_FUNCTION(cfq_slice_async_us_store, &cfqd->cfq_slice[0], 1, UINT_MAX); +#undef USEC_STORE_FUNCTION + #define CFQ_ATTR(name) \ __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) @@ -4562,10 +4602,14 @@ static struct elv_fs_entry cfq_attrs[] = { CFQ_ATTR(back_seek_max), CFQ_ATTR(back_seek_penalty), CFQ_ATTR(slice_sync), + CFQ_ATTR(slice_sync_us), CFQ_ATTR(slice_async), + CFQ_ATTR(slice_async_us), CFQ_ATTR(slice_async_rq), CFQ_ATTR(slice_idle), + CFQ_ATTR(slice_idle_us), CFQ_ATTR(group_idle), + CFQ_ATTR(group_idle_us), CFQ_ATTR(low_latency), CFQ_ATTR(target_latency), __ATTR_NULL