From: john stultz <johnstul@us.ibm.com>
To: Andrew Morton <akpm@osdl.org>
Cc: Andi Kleen <ak@suse.de>, lkml <linux-kernel@vger.kernel.org>
Subject: [PATCH] x86-64: Fix bad assumption that dualcore cpus have synced TSCs (resend)
Date: Mon, 26 Sep 2005 12:46:52 -0700 [thread overview]
Message-ID: <1127764012.8195.138.camel@cog.beaverton.ibm.com> (raw)
Andrew,
This patch should resolve the issue seen in bugme bug #5105, where it
is assumed that dualcore x86_64 systems have synced TSCs. This is not
the case, and alternate timesources should be used instead.
For more details, see:
http://bugzilla.kernel.org/show_bug.cgi?id=5105
Andi's earlier concerns that the TSCs should be synced on dualcore
systems have been resolved by confirmation from AMD folks that they can
be unsynced.
Please consider for inclusion in your tree.
thanks
-john
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -959,9 +959,6 @@ static __init int unsynchronized_tsc(voi
are handled in the OEM check above. */
if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
return 0;
- /* All in a single socket - should be synchronized */
- if (cpus_weight(cpu_core_map[0]) == num_online_cpus())
- return 0;
#endif
/* Assume multi socket systems are not synchronized */
return num_online_cpus() > 1;
next reply other threads:[~2005-09-26 19:47 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-26 19:46 john stultz [this message]
2005-09-26 20:33 ` Andrew Morton
2005-09-27 8:34 ` Andi Kleen
2005-09-26 22:15 ` Stefan Smietanowski
2005-09-26 22:28 ` john stultz
2005-09-26 23:31 ` Stefan Smietanowski
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=1127764012.8195.138.camel@cog.beaverton.ibm.com \
--to=johnstul@us.ibm.com \
--cc=ak@suse.de \
--cc=akpm@osdl.org \
--cc=linux-kernel@vger.kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®