linux-kernel - [PATCH 1/2] sched/topology: Set correct numa topology type

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]

Message-Id: <1533920419-17410-1-git-send-email-srikar@linux.vnet.ibm.com>
Date:   Fri, 10 Aug 2018 22:30:18 +0530
From:   Srikar Dronamraju <srikar@...ux.vnet.ibm.com>
To:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>
Cc:     Srikar Dronamraju <srikar@...ux.vnet.ibm.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Mel Gorman <mgorman@...hsingularity.net>,
        Rik van Riel <riel@...riel.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Michael Ellerman <mpe@...erman.id.au>,
        Heiko Carstens <heiko.carstens@...ibm.com>,
        Suravee Suthikulpanit <suravee.suthikulpanit@....com>,
        Andre Wild <wild@...ux.vnet.ibm.com>,
        linuxppc-dev <linuxppc-dev@...ts.ozlabs.org>
Subject: [PATCH 1/2] sched/topology: Set correct numa topology type

With commit 051f3ca02e46 ("sched/topology: Introduce NUMA identity node
sched domain") scheduler introduces an new numa level. However this
leads to numa topology on 2 node systems no more marked as NUMA_DIRECT.
After this commit, it gets reported as NUMA_BACKPLANE. This is because
sched_domains_numa_level is now 2 on 2 node systems.

Fix this by allowing setting systems that have upto 2 numa levels as
NUMA_DIRECT.

While here remove a code that assumes level can be 0.

Fixes: 051f3ca02e46 "Introduce NUMA identity node sched domain"
Signed-off-by: Srikar Dronamraju <srikar@...ux.vnet.ibm.com>
---
 kernel/sched/topology.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index a6e6b855ba81..cec3ee3ed320 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1315,7 +1315,7 @@ static void init_numa_topology_type(void)
 
 	n = sched_max_numa_distance;
 
-	if (sched_domains_numa_levels <= 1) {
+	if (sched_domains_numa_levels <= 2) {
 		sched_numa_topology_type = NUMA_DIRECT;
 		return;
 	}
@@ -1400,9 +1400,6 @@ void sched_init_numa(void)
 			break;
 	}
 
-	if (!level)
-		return;
-
 	/*
 	 * 'level' contains the number of unique distances
 	 *
-- 
2.12.3