From: Peter Zijlstra <peterz@infradead.org>
To: bharata@linux.vnet.ibm.com
Cc: linux-kernel@vger.kernel.org,
Dhaval Giani <dhaval.giani@gmail.com>,
Balbir Singh <balbir@linux.vnet.ibm.com>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
Srivatsa Vaddagiri <vatsa@in.ibm.com>,
Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>,
Ingo Molnar <mingo@elte.hu>, Pavel Emelyanov <xemul@openvz.org>,
Herbert Poetzl <herbert@13thfloor.at>,
Avi Kivity <avi@redhat.com>, Chris Friesen <cfriesen@nortel.com>,
Paul Menage <menage@google.com>,
Mike Waychison <mikew@google.com>, Paul Turner <pjt@google.com>,
Nikhil Rao <ncrao@google.com>
Subject: Re: [PATCH v3 2/7] sched: accumulate per-cfs_rq cpu usage
Date: Thu, 14 Oct 2010 11:01:40 +0200 [thread overview]
Message-ID: <1287046900.29097.161.camel@twins> (raw)
In-Reply-To: <20101012075109.GC9893@in.ibm.com>
On Tue, 2010-10-12 at 13:21 +0530, Bharata B Rao wrote:
> +static void account_cfs_rq_quota(struct cfs_rq *cfs_rq,
> + unsigned long delta_exec)
> +{
> + if (cfs_rq->quota_assigned == RUNTIME_INF)
> + return;
> +
> + cfs_rq->quota_used += delta_exec;
> +
> + if (cfs_rq->quota_used < cfs_rq->quota_assigned)
> + return;
> +
> + cfs_rq->quota_assigned += tg_request_cfs_quota(cfs_rq->tg);
> +}
That looks iffy, quota_assigned is only ever incremented and can wrap.
Why not subtract delta_exec and replenish when <0? That keeps the
numbers small.
next prev parent reply other threads:[~2010-10-14 9:02 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-12 7:49 [PATCH v3 0/7] CFS Bandwidth Control Bharata B Rao
2010-10-12 7:50 ` [PATCH v3 1/7] sched: introduce primitives to account for CFS bandwidth tracking Bharata B Rao
2010-10-13 13:00 ` Balbir Singh
2010-10-14 5:14 ` Bharata B Rao
2010-10-14 7:52 ` Peter Zijlstra
2010-10-14 12:38 ` Balbir Singh
2010-10-14 13:24 ` Peter Zijlstra
2010-12-06 9:02 ` Bharata B Rao
2010-10-12 7:51 ` [PATCH v3 2/7] sched: accumulate per-cfs_rq cpu usage Bharata B Rao
2010-10-13 13:30 ` Balbir Singh
2010-10-13 13:46 ` Nikhil Rao
2010-10-13 13:59 ` Balbir Singh
2010-10-13 14:41 ` Nikhil Rao
2010-10-14 5:39 ` Balbir Singh
2010-10-14 8:57 ` Peter Zijlstra
2010-10-14 9:07 ` Paul Turner
2010-10-14 9:13 ` Peter Zijlstra
2010-10-14 9:01 ` Peter Zijlstra [this message]
2010-10-14 9:14 ` Paul Turner
2010-10-14 9:27 ` Peter Zijlstra
2010-10-14 9:53 ` Paul Turner
2010-10-14 9:19 ` Peter Zijlstra
2010-10-14 9:27 ` Paul Turner
2010-10-14 9:40 ` Bharata B Rao
2010-10-12 7:52 ` [PATCH v3 3/7] sched: throttle cfs_rq entities which exceed their local quota Bharata B Rao
2010-10-13 6:34 ` KAMEZAWA Hiroyuki
2010-10-13 6:44 ` Paul Turner
2010-10-13 6:47 ` Bharata B Rao
2010-10-13 6:52 ` Paul Turner
2010-10-13 7:00 ` KAMEZAWA Hiroyuki
2010-10-13 7:13 ` Paul Turner
2010-10-14 9:12 ` Peter Zijlstra
2010-10-14 9:50 ` KAMEZAWA Hiroyuki
2010-10-14 9:59 ` Peter Zijlstra
2010-10-14 10:08 ` KAMEZAWA Hiroyuki
2010-10-14 10:25 ` Paul Turner
2010-10-14 10:41 ` Peter Zijlstra
2010-10-14 23:30 ` KAMEZAWA Hiroyuki
2010-10-14 10:37 ` Peter Zijlstra
2010-10-14 9:58 ` Paul Turner
2010-10-12 7:52 ` [PATCH v3 4/7] sched: unthrottle cfs_rq(s) who ran out of quota at period refresh Bharata B Rao
2010-10-15 4:45 ` Balbir Singh
2010-12-07 13:13 ` Bharata B Rao
2010-10-12 7:53 ` [PATCH v3 5/7] sched: add exports tracking cfs bandwidth control statistics Bharata B Rao
2010-10-12 7:54 ` [PATCH v3 6/7] sched: hierarchical task accounting for FAIR_GROUP_SCHED Bharata B Rao
2010-10-12 7:55 ` [PATCH v3 7/7] sched: Return/expire slack quota using generation counters Bharata B Rao
2010-10-13 5:14 ` [PATCH v3 0/7] CFS Bandwidth Control KAMEZAWA Hiroyuki
2010-10-13 5:44 ` Herbert Poetzl
2010-10-13 6:26 ` Paul Turner
2010-11-17 8:32 ` Lai Jiangshan
2010-11-19 3:24 ` Bharata B Rao
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