Commit-ID: ceb1cbac8eda66cf0f889def226b4e82f8ff857b
Gitweb: http://git.kernel.org/tip/ceb1cbac8eda66cf0f889def226b4e82f8ff857b
Author: Kamalesh Babulal <kamalesh@xxxxxxxxxxxxxxxxxx>
AuthorDate: Thu, 31 May 2012 13:07:38 +0530
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 6 Jun 2012 16:37:59 +0200
sched/x86: Calculate booted cores after construction of sibling_mask
Commit 316ad248307fb ("sched/x86: Rewrite set_cpu_sibling_map()")
broke the booted_cores accounting.
The problem is that the booted_cores accounting needs all the
sibling links set up. So restore the second loop and add a comment as
to why its needed.
On qemu booted with -smp sockets=1,cores=2,threads=2;
Before:
$ grep cores /proc/cpuinfo
cpu cores : 2
cpu cores : 1
cpu cores : 4
cpu cores : 3
With the patch:
$ grep cores /proc/cpuinfo
cpu cores : 2
cpu cores : 2
cpu cores : 2
cpu cores : 2
Reported-by: Prarit Bhargava <prarit@xxxxxxxxxx>
Reported-by: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Kamalesh Babulal <kamalesh@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20120531073738.GH7511@xxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/smpboot.c | 9 +++++++++
1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index fd019d7..3fab55b 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -382,6 +382,15 @@ void __cpuinit set_cpu_sibling_map(int cpu)
if ((i == cpu) || (has_mc && match_llc(c, o)))
link_mask(llc_shared, cpu, i);
+ }
+
+ /*
+ * This needs a separate iteration over the cpus because we rely on all
+ * cpu_sibling_mask links to be set-up.
+ */
+ for_each_cpu(i, cpu_sibling_setup_mask) {
+ o = &cpu_data(i);
+
if ((i == cpu) || (has_mc && match_mc(c, o))) {
link_mask(core, cpu, i);
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|