Commit-ID: b0bc225d0e5de887340d4d92a8c594ef0f60d412
Gitweb: http://git.kernel.org/tip/b0bc225d0e5de887340d4d92a8c594ef0f60d412
Author: Andrew Jones <drjones@xxxxxxxxxx>
AuthorDate: Wed, 29 May 2013 14:48:15 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 31 May 2013 13:10:38 +0200
sched/x86: Construct all sibling maps if smt
Commit 316ad248307fb ("sched/x86: Rewrite
set_cpu_sibling_map()") broke the construction of sibling maps,
which also broke the booted_cores accounting.
Before the rewrite, if smt was present, then each map was
updated for each smt sibling. After the rewrite only
cpu_sibling_mask gets updated, as the llc and core maps depend
on 'has_mc = x86_max_cores > 1' instead. This leads to problems
with topologies like the following
(qemu -smp sockets=2,cores=1,threads=2)
processor : 0
physical id : 0
siblings : 1 <= should be 2
core id : 0
cpu cores : 1
processor : 1
physical id : 0
siblings : 1 <= should be 2
core id : 0
cpu cores : 0 <= should be 1
processor : 2
physical id : 1
siblings : 1 <= should be 2
core id : 0
cpu cores : 1
processor : 3
physical id : 1
siblings : 1 <= should be 2
core id : 0
cpu cores : 0 <= should be 1
This patch restores the former construction by defining has_mc
as (has_smt || x86_max_cores > 1). This should be fine as there
were no (has_smt && !has_mc) conditions in the context.
Aso rename has_mc to has_mp now that it's not just for cores.
Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx>
Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: a.p.zijlstra@xxxxxxxxx
Cc: fenghua.yu@xxxxxxxxx
Link: http://lkml.kernel.org/r/1369831695-11970-1-git-send-email-drjones@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/smpboot.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 9c73b51..bfd348e 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -372,15 +372,15 @@ static bool __cpuinit match_mc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
void __cpuinit set_cpu_sibling_map(int cpu)
{
- bool has_mc = boot_cpu_data.x86_max_cores > 1;
bool has_smt = smp_num_siblings > 1;
+ bool has_mp = has_smt || boot_cpu_data.x86_max_cores > 1;
struct cpuinfo_x86 *c = &cpu_data(cpu);
struct cpuinfo_x86 *o;
int i;
cpumask_set_cpu(cpu, cpu_sibling_setup_mask);
- if (!has_smt && !has_mc) {
+ if (!has_mp) {
cpumask_set_cpu(cpu, cpu_sibling_mask(cpu));
cpumask_set_cpu(cpu, cpu_llc_shared_mask(cpu));
cpumask_set_cpu(cpu, cpu_core_mask(cpu));
@@ -394,7 +394,7 @@ void __cpuinit set_cpu_sibling_map(int cpu)
if ((i == cpu) || (has_smt && match_smt(c, o)))
link_mask(sibling, cpu, i);
- if ((i == cpu) || (has_mc && match_llc(c, o)))
+ if ((i == cpu) || (has_mp && match_llc(c, o)))
link_mask(llc_shared, cpu, i);
}
@@ -406,7 +406,7 @@ void __cpuinit set_cpu_sibling_map(int cpu)
for_each_cpu(i, cpu_sibling_setup_mask) {
o = &cpu_data(i);
- if ((i == cpu) || (has_mc && match_mc(c, o))) {
+ if ((i == cpu) || (has_mp && match_mc(c, o))) {
link_mask(core, cpu, i);
/*
--
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