From: Tim Chen <tim.c.chen@linux.intel.com>
To: Steve Sistare <steven.sistare@oracle.com>,
mingo@redhat.com, peterz@infradead.org
Cc: subhra.mazumdar@oracle.com, dhaval.giani@oracle.com,
daniel.m.jordan@oracle.com, pavel.tatashin@microsoft.com,
matt@codeblueprint.co.uk, umgwanakikbuti@gmail.com,
riel@redhat.com, jbacik@fb.com, juri.lelli@redhat.com,
valentin.schneider@arm.com, vincent.guittot@linaro.org,
quentin.perret@arm.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 01/10] sched: Provide sparsemask, a reduced contention bitmap
Date: Thu, 31 Jan 2019 11:18:47 -0800 [thread overview]
Message-ID: <ebcb37f6-ae2f-b9fa-4911-e6b135cd65e8@linux.intel.com> (raw)
In-Reply-To: <1544131696-2888-2-git-send-email-steven.sistare@oracle.com>
On 12/6/18 1:28 PM, Steve Sistare wrote:
> Provide struct sparsemask and functions to manipulate it. A sparsemask is
> a sparse bitmap. It reduces cache contention vs the usual bitmap when many
> threads concurrently set, clear, and visit elements, by reducing the number
> of significant bits per cacheline. For each cacheline chunk of the mask,
> only the first K bits of the first word are used, and the remaining bits
> are ignored, where K is a creation time parameter. Thus a sparsemask that
> can represent a set of N elements is approximately (N/K * CACHELINE) bytes
> in size.
>
> This type is simpler and more efficient than the struct sbitmap used by
> block drivers.
>
> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Steve,
We did a test of this patch set with an OLTP benchmark using Oracle database
on a 2 socket SKX platform with 2 X 28 cores. The patchset boosted the
performance by 3.5%.
The percentage of cpu idle time is lowered by 5%,
with user time increased by 4% and kernel time increased by 1%,
indicating a better cpu utilization overall.
The performance looks encouraging.
Thanks.
Tim
next prev parent reply other threads:[~2019-01-31 19:18 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-06 21:28 [PATCH v4 00/10] steal tasks to improve CPU utilization Steve Sistare
2018-12-06 21:28 ` [PATCH v4 01/10] sched: Provide sparsemask, a reduced contention bitmap Steve Sistare
2019-01-31 19:18 ` Tim Chen [this message]
2018-12-06 21:28 ` [PATCH v4 02/10] sched/topology: Provide hooks to allocate data shared per LLC Steve Sistare
2018-12-06 21:28 ` [PATCH v4 03/10] sched/topology: Provide cfs_overload_cpus bitmap Steve Sistare
2018-12-07 20:20 ` Valentin Schneider
2018-12-07 22:35 ` Steven Sistare
2018-12-08 18:33 ` Valentin Schneider
2018-12-06 21:28 ` [PATCH v4 04/10] sched/fair: Dynamically update cfs_overload_cpus Steve Sistare
2018-12-07 20:20 ` Valentin Schneider
2018-12-07 22:35 ` Steven Sistare
2018-12-08 18:47 ` Valentin Schneider
2018-12-06 21:28 ` [PATCH v4 05/10] sched/fair: Hoist idle_stamp up from idle_balance Steve Sistare
2018-12-06 21:28 ` [PATCH v4 06/10] sched/fair: Generalize the detach_task interface Steve Sistare
2018-12-06 21:28 ` [PATCH v4 07/10] sched/fair: Provide can_migrate_task_llc Steve Sistare
2018-12-06 21:28 ` [PATCH v4 08/10] sched/fair: Steal work from an overloaded CPU when CPU goes idle Steve Sistare
2018-12-07 20:21 ` Valentin Schneider
2018-12-07 22:36 ` Steven Sistare
2018-12-08 18:39 ` Valentin Schneider
2018-12-06 21:28 ` [PATCH v4 09/10] sched/fair: disable stealing if too many NUMA nodes Steve Sistare
2018-12-07 11:43 ` Valentin Schneider
2018-12-07 13:37 ` Steven Sistare
2018-12-06 21:28 ` [PATCH v4 10/10] sched/fair: Provide idle search schedstats Steve Sistare
2018-12-07 11:56 ` Valentin Schneider
2018-12-07 13:45 ` Steven Sistare
2018-12-24 12:25 ` Rick Lindsley
2019-01-14 17:04 ` Steven Sistare
2018-12-07 20:30 ` [PATCH v4 00/10] steal tasks to improve CPU utilization Valentin Schneider
2018-12-07 22:36 ` Steven Sistare
2019-02-01 15:07 ` Valentin Schneider
2018-12-10 16:10 ` Vincent Guittot
2018-12-10 16:29 ` Steven Sistare
2018-12-10 16:33 ` Vincent Guittot
2018-12-10 17:08 ` Vincent Guittot
2018-12-10 17:20 ` Steven Sistare
2018-12-10 17:06 ` Valentin Schneider
2019-01-04 13:44 ` Shijith Thotton
2019-01-14 16:55 ` Steven Sistare
2019-01-31 17:16 ` Dhaval Giani
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