From b0bc225d0e5de887340d4d92a8c594ef0f60d412 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Wed, 29 May 2013 14:48:15 +0200 Subject: [PATCH] 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 Acked-by: Peter Zijlstra Cc: a.p.zijlstra@chello.nl Cc: fenghua.yu@intel.com Link: http://lkml.kernel.org/r/1369831695-11970-1-git-send-email-drjones@redhat.com Signed-off-by: Ingo Molnar --- 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 9c73b51817e4..bfd348e99369 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); /* -- 2.20.1