From 2a371f7d5fa575010b915e325c5d20b9ad0d5d5a Mon Sep 17 00:00:00 2001 From: Chengming Zhou Date: Tue, 10 May 2022 11:47:57 +0800 Subject: [PATCH] blk-iocost: combine local_stat and desc_stat to stat When we flush usage, wait, indebt stat in iocg_flush_stat(), we use local_stat and desc_stat, which has no point since the leaf iocg only has local_stat and the inner iocg only has desc_stat. Also we don't need to flush percpu abs_vusage for these inner iocgs. This patch combine local_stat and desc_stat to stat, only flush percpu abs_vusage for active leaf iocgs, then build inner walk list to propagate. Signed-off-by: Chengming Zhou Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220510034757.21761-1-zhouchengming@bytedance.com Signed-off-by: Jens Axboe --- block/blk-iocost.c | 71 ++++++++++++++++++++++++------------------------------ 1 file changed, 32 insertions(+), 39 deletions(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 70a0a3d..bf83288 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -533,8 +533,7 @@ struct ioc_gq { /* statistics */ struct iocg_pcpu_stat __percpu *pcpu_stat; - struct iocg_stat local_stat; - struct iocg_stat desc_stat; + struct iocg_stat stat; struct iocg_stat last_stat; u64 last_stat_abs_vusage; u64 usage_delta_us; @@ -1371,7 +1370,7 @@ static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) return true; } else { if (iocg->indelay_since) { - iocg->local_stat.indelay_us += now->now - iocg->indelay_since; + iocg->stat.indelay_us += now->now - iocg->indelay_since; iocg->indelay_since = 0; } iocg->delay = 0; @@ -1419,7 +1418,7 @@ static void iocg_pay_debt(struct ioc_gq *iocg, u64 abs_vpay, /* if debt is paid in full, restore inuse */ if (!iocg->abs_vdebt) { - iocg->local_stat.indebt_us += now->now - iocg->indebt_since; + iocg->stat.indebt_us += now->now - iocg->indebt_since; iocg->indebt_since = 0; propagate_weights(iocg, iocg->active, iocg->last_inuse, @@ -1513,7 +1512,7 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, bool pay_debt, if (!waitqueue_active(&iocg->waitq)) { if (iocg->wait_since) { - iocg->local_stat.wait_us += now->now - iocg->wait_since; + iocg->stat.wait_us += now->now - iocg->wait_since; iocg->wait_since = 0; } return; @@ -1641,11 +1640,30 @@ static void iocg_build_inner_walk(struct ioc_gq *iocg, } } +/* propagate the deltas to the parent */ +static void iocg_flush_stat_upward(struct ioc_gq *iocg) +{ + if (iocg->level > 0) { + struct iocg_stat *parent_stat = + &iocg->ancestors[iocg->level - 1]->stat; + + parent_stat->usage_us += + iocg->stat.usage_us - iocg->last_stat.usage_us; + parent_stat->wait_us += + iocg->stat.wait_us - iocg->last_stat.wait_us; + parent_stat->indebt_us += + iocg->stat.indebt_us - iocg->last_stat.indebt_us; + parent_stat->indelay_us += + iocg->stat.indelay_us - iocg->last_stat.indelay_us; + } + + iocg->last_stat = iocg->stat; +} + /* collect per-cpu counters and propagate the deltas to the parent */ -static void iocg_flush_stat_one(struct ioc_gq *iocg, struct ioc_now *now) +static void iocg_flush_stat_leaf(struct ioc_gq *iocg, struct ioc_now *now) { struct ioc *ioc = iocg->ioc; - struct iocg_stat new_stat; u64 abs_vusage = 0; u64 vusage_delta; int cpu; @@ -1661,34 +1679,9 @@ static void iocg_flush_stat_one(struct ioc_gq *iocg, struct ioc_now *now) iocg->last_stat_abs_vusage = abs_vusage; iocg->usage_delta_us = div64_u64(vusage_delta, ioc->vtime_base_rate); - iocg->local_stat.usage_us += iocg->usage_delta_us; - - /* propagate upwards */ - new_stat.usage_us = - iocg->local_stat.usage_us + iocg->desc_stat.usage_us; - new_stat.wait_us = - iocg->local_stat.wait_us + iocg->desc_stat.wait_us; - new_stat.indebt_us = - iocg->local_stat.indebt_us + iocg->desc_stat.indebt_us; - new_stat.indelay_us = - iocg->local_stat.indelay_us + iocg->desc_stat.indelay_us; - - /* propagate the deltas to the parent */ - if (iocg->level > 0) { - struct iocg_stat *parent_stat = - &iocg->ancestors[iocg->level - 1]->desc_stat; - - parent_stat->usage_us += - new_stat.usage_us - iocg->last_stat.usage_us; - parent_stat->wait_us += - new_stat.wait_us - iocg->last_stat.wait_us; - parent_stat->indebt_us += - new_stat.indebt_us - iocg->last_stat.indebt_us; - parent_stat->indelay_us += - new_stat.indelay_us - iocg->last_stat.indelay_us; - } + iocg->stat.usage_us += iocg->usage_delta_us; - iocg->last_stat = new_stat; + iocg_flush_stat_upward(iocg); } /* get stat counters ready for reading on all active iocgs */ @@ -1699,13 +1692,13 @@ static void iocg_flush_stat(struct list_head *target_iocgs, struct ioc_now *now) /* flush leaves and build inner node walk list */ list_for_each_entry(iocg, target_iocgs, active_list) { - iocg_flush_stat_one(iocg, now); + iocg_flush_stat_leaf(iocg, now); iocg_build_inner_walk(iocg, &inner_walk); } /* keep flushing upwards by walking the inner list backwards */ list_for_each_entry_safe_reverse(iocg, tiocg, &inner_walk, walk_list) { - iocg_flush_stat_one(iocg, now); + iocg_flush_stat_upward(iocg); list_del_init(&iocg->walk_list); } } @@ -2152,16 +2145,16 @@ static int ioc_check_iocgs(struct ioc *ioc, struct ioc_now *now) /* flush wait and indebt stat deltas */ if (iocg->wait_since) { - iocg->local_stat.wait_us += now->now - iocg->wait_since; + iocg->stat.wait_us += now->now - iocg->wait_since; iocg->wait_since = now->now; } if (iocg->indebt_since) { - iocg->local_stat.indebt_us += + iocg->stat.indebt_us += now->now - iocg->indebt_since; iocg->indebt_since = now->now; } if (iocg->indelay_since) { - iocg->local_stat.indelay_us += + iocg->stat.indelay_us += now->now - iocg->indelay_since; iocg->indelay_since = now->now; } -- 2.7.4