All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dave Hansen <dave@sr71.net>
To: linux-kernel@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>,
	dave.hansen@linux.intel.com, akpm@linux-foundation.org,
	peterz@infradead.org, mingo@kernel.org
Subject: [PATCH] x86, sched: fix up typo in topology detection
Date: Tue, 30 Sep 2014 14:45:46 -0700	[thread overview]
Message-ID: <20140930214546.FD481CFF@viggo.jf.intel.com> (raw)


From: Dave Hansen <dave.hansen@linux.intel.com>

Commit cebf15eb09 (in linux-next now) added some code to try to
detect the situation where we have a NUMA node inside of the
"DIE" sched domain.  It detected this by looking for cpus which
match_die() but do not match NUMA nodes via topology_same_node().

I wrote it up as:

	if (match_die(c, o) == !topology_same_node(c, o))

which actually seemed to work some of the time, albiet
accidentally.

It should have been doing an &&, not an ==.

This code essentially chopped off the "DIE" domain on one of
Andrew Morton's systems.  He reported that this patch fixed his
issue.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
---

 b/arch/x86/kernel/smpboot.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN arch/x86/kernel/smpboot.c~fix-up-typo arch/x86/kernel/smpboot.c
--- a/arch/x86/kernel/smpboot.c~fix-up-typo	2014-09-30 14:24:52.934235516 -0700
+++ b/arch/x86/kernel/smpboot.c	2014-09-30 14:30:42.074917876 -0700
@@ -445,7 +445,7 @@ void set_cpu_sibling_map(int cpu)
 			} else if (i != cpu && !c->booted_cores)
 				c->booted_cores = cpu_data(i).booted_cores;
 		}
-		if (match_die(c, o) == !topology_same_node(c, o))
+		if (match_die(c, o) && !topology_same_node(c, o))
 			primarily_use_numa_for_topology();
 	}
 }
_

             reply	other threads:[~2014-09-30 21:46 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-30 21:45 Dave Hansen [this message]
2014-10-03  5:27 ` [tip:sched/core] sched/x86: Fix up typo in topology detection tip-bot for Dave Hansen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20140930214546.FD481CFF@viggo.jf.intel.com \
    --to=dave@sr71.net \
    --cc=akpm@linux-foundation.org \
    --cc=dave.hansen@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.