From: Peter Zijlstra <peterz@infradead.org>
To: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Cc: mingo@kernel.org, LKML <linux-kernel@vger.kernel.org>,
roland@kernel.org, Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
efault@gmx.de, Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH v3] sched: balance_cpu to consider other cpus in its group as target of (pinned) task
Date: Wed, 20 Jun 2012 19:38:21 +0200 [thread overview]
Message-ID: <1340213901.21745.122.camel@twins> (raw)
In-Reply-To: <4FE06CDB.2060605@linux.vnet.ibm.com>
On Tue, 2012-06-19 at 17:43 +0530, Prashanth Nageshappa wrote:
> T2 will starve eternally in this case. The same
> scenario can arise in presence of non-rt tasks as well (say we replace F1 with
> high irq load or with a very high priority SCHED_OTHER task that can't move out
> of C2).
Uhm, no. In the case where both F1 and T2 are SCHED_OTHER starvation is
impossible.
What can happen with pure SCHED_OTHER affinities is being less fair than
desired.
Anyway, I took the patch with a few minor edits -- ie. we don't need to
reset loop_break, its never changed (same for the ALL_PINNED patch you
sent).
next prev parent reply other threads:[~2012-06-20 17:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-19 12:13 [PATCH v3] sched: balance_cpu to consider other cpus in its group as target of (pinned) task Prashanth Nageshappa
2012-06-20 17:38 ` Peter Zijlstra [this message]
2012-06-21 3:40 ` Srivatsa Vaddagiri
2012-06-21 4:23 ` Srivatsa Vaddagiri
2012-06-21 5:24 ` Prashanth Nageshappa
2012-06-21 8:34 ` Peter Zijlstra
2012-06-20 17:40 ` Peter Zijlstra
2012-07-06 6:23 ` [tip:sched/core] sched: Improve balance_cpu() " tip-bot for Srivatsa Vaddagiri
2012-07-24 14:20 ` tip-bot for Srivatsa Vaddagiri
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