On Wed, Aug 10, 2016 at 05:52:05PM +0200, Peter Zijlstra wrote:
> On Wed, Aug 10, 2016 at 04:15:38PM +0200, Jiri Olsa wrote:
> > it's very likely I'm missing something, but seems to me
> > that attached patch (untested) might work as well
>
> Hmm, I think you're right. Earlier code (which hasn't survived) tried to
> match logical and physical if possible, but that was busted and got
> removed.
>
> The code as is should indeed allow for this.
>
> Maybe one nit, the variable is no longer used for a max, so maybe rename
> it too?
ok, renaming it to logical_packages then, attaching full patch
thanks,
jirka
---
The fix is to remove logical_package_map bitmap completely
and just keep and update the logical_packages number.
arch/x86/include/asm/topology.h | 4 ++--
arch/x86/kernel/smpboot.c | 21 +++++----------------
2 files changed, 7 insertions(+), 18 deletions(-)
diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index cf75871d2f81..c28010088651 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -118,8 +118,8 @@ extern const struct cpumask *cpu_coregroup_mask(int cpu);
#define topology_core_cpumask(cpu) (per_cpu(cpu_core_map, cpu))
#define topology_sibling_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu))
-extern unsigned int __max_logical_packages;
-#define topology_max_packages() (__max_logical_packages)
+extern unsigned int logical_packages;
+#define topology_max_packages() (logical_packages)
extern int __max_smt_threads;
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 157bf0957219..b1b775dbede6 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -100,10 +100,9 @@ EXPORT_PER_CPU_SYMBOL(cpu_info);
/* Logical package management. We might want to allocate that dynamically */
static int *physical_to_logical_pkg __read_mostly;
static unsigned long *physical_package_map __read_mostly;;
-static unsigned long *logical_package_map __read_mostly;
static unsigned int max_physical_pkg_id __read_mostly;
-unsigned int __max_logical_packages __read_mostly;
-EXPORT_SYMBOL(__max_logical_packages);
+unsigned int logical_packages __read_mostly;
+EXPORT_SYMBOL(logical_packages);
/* Maximum number of SMT threads on any online core */
int __max_smt_threads __read_mostly;
@@ -277,14 +276,8 @@ int topology_update_package_map(unsigned int apicid, unsigned int cpu)
if (test_and_set_bit(pkg, physical_package_map))
goto found;
- new = find_first_zero_bit(logical_package_map, __max_logical_packages);
- if (new >= __max_logical_packages) {
- physical_to_logical_pkg[pkg] = -1;
- pr_warn("APIC(%x) Package %u exceeds logical package map\n",
- apicid, pkg);
- return -ENOSPC;
- }
- set_bit(new, logical_package_map);
+ new = logical_packages++;
+
pr_info("APIC(%x) Converting physical %u to logical package %u\n",
apicid, pkg, new);
physical_to_logical_pkg[pkg] = new;
@@ -340,7 +333,7 @@ static void __init smp_init_package_map(void)
ncpus = 1;
}
- __max_logical_packages = DIV_ROUND_UP(total_cpus, ncpus);
+ logical_packages = 0;
/*
* Possibly larger than what we need as the number of apic ids per
@@ -352,10 +345,6 @@ static void __init smp_init_package_map(void)
memset(physical_to_logical_pkg, 0xff, size);
size = BITS_TO_LONGS(max_physical_pkg_id) * sizeof(unsigned long);
physical_package_map = kzalloc(size, GFP_KERNEL);
- size = BITS_TO_LONGS(__max_logical_packages) * sizeof(unsigned long);
- logical_package_map = kzalloc(size, GFP_KERNEL);
-
- pr_info("Max logical packages: %u\n", __max_logical_packages);
for_each_present_cpu(cpu) {
unsigned int apicid = apic->cpu_present_to_apicid(cpu);
--
2.4.11