linux-kernel - [PATCH] sched/numa: recovered SD_PERFER

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 20 Jul 2012 14:19:50 +0800
From:	Alex Shi <alex.shi@...el.com>
To:	a.p.zijlstra@...llo.nl
Cc:	tj@...nel.org, alex.shi@...el.com, mingo@...nel.org,
	akpm@...ux-foundation.org, linux-kernel@...r.kernel.org
Subject: [PATCH] sched/numa: recovered SD_PERFER_SIBLING on CPU domain

commit 8e7fbcbc22c(sched: Remove stale power aware scheduling remnants
and dysfunctional knobs) removed SD_PERFER_SIBLING on CPU domain
On numa machine, that causes load_balance didn't perfer LCPU in same
physical CPU package.

It causes some regression on our numa machines from core2 to NHM and SNB.
Recover this domain flag can recover the performance drop.

This recovery doesn't has any bad impact on my all benchmarks specjbb,
kbuild, fio, hackbench .. etc, on all my machines.
Since it is a recovery, I assume it also has no bad impact for other
platforms.

Signed-off-by: Alex Shi <alex.shi@...el.com>
---
 include/linux/topology.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/include/linux/topology.h b/include/linux/topology.h
index e91cd43..fec12d6 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -164,6 +164,7 @@ int arch_update_cpu_topology(void);
 				| 0*SD_SHARE_CPUPOWER			\
 				| 0*SD_SHARE_PKG_RESOURCES		\
 				| 0*SD_SERIALIZE			\
+				| 1*SD_PREFER_SIBLING			\
 				,					\
 	.last_balance		= jiffies,				\
 	.balance_interval	= 1,					\
-- 
1.7.5.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/