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-rw-r--r--arch/powerpc/include/asm/cputhreads.h16
-rw-r--r--arch/powerpc/mm/mmu_context_nohash.c93
-rw-r--r--arch/powerpc/mm/tlb_nohash.c10
3 files changed, 86 insertions, 33 deletions
diff --git a/arch/powerpc/include/asm/cputhreads.h b/arch/powerpc/include/asm/cputhreads.h
index fb11b0c459b..a8e18447c62 100644
--- a/arch/powerpc/include/asm/cputhreads.h
+++ b/arch/powerpc/include/asm/cputhreads.h
@@ -5,6 +5,15 @@
/*
* Mapping of threads to cores
+ *
+ * Note: This implementation is limited to a power of 2 number of
+ * threads per core and the same number for each core in the system
+ * (though it would work if some processors had less threads as long
+ * as the CPU numbers are still allocated, just not brought offline).
+ *
+ * However, the API allows for a different implementation in the future
+ * if needed, as long as you only use the functions and not the variables
+ * directly.
*/
#ifdef CONFIG_SMP
@@ -67,5 +76,12 @@ static inline int cpu_first_thread_in_core(int cpu)
return cpu & ~(threads_per_core - 1);
}
+static inline int cpu_last_thread_in_core(int cpu)
+{
+ return cpu | (threads_per_core - 1);
+}
+
+
+
#endif /* _ASM_POWERPC_CPUTHREADS_H */
diff --git a/arch/powerpc/mm/mmu_context_nohash.c b/arch/powerpc/mm/mmu_context_nohash.c
index b1a727def15..834436d6d6b 100644
--- a/arch/powerpc/mm/mmu_context_nohash.c
+++ b/arch/powerpc/mm/mmu_context_nohash.c
@@ -25,10 +25,20 @@
* also clear mm->cpu_vm_mask bits when processes are migrated
*/
-#undef DEBUG
-#define DEBUG_STEAL_ONLY
-#undef DEBUG_MAP_CONSISTENCY
-/*#define DEBUG_CLAMP_LAST_CONTEXT 15 */
+#define DEBUG_MAP_CONSISTENCY
+#define DEBUG_CLAMP_LAST_CONTEXT 31
+//#define DEBUG_HARDER
+
+/* We don't use DEBUG because it tends to be compiled in always nowadays
+ * and this would generate way too much output
+ */
+#ifdef DEBUG_HARDER
+#define pr_hard(args...) printk(KERN_DEBUG args)
+#define pr_hardcont(args...) printk(KERN_CONT args)
+#else
+#define pr_hard(args...) do { } while(0)
+#define pr_hardcont(args...) do { } while(0)
+#endif
#include <linux/kernel.h>
#include <linux/mm.h>
@@ -71,7 +81,7 @@ static DEFINE_SPINLOCK(context_lock);
static unsigned int steal_context_smp(unsigned int id)
{
struct mm_struct *mm;
- unsigned int cpu, max;
+ unsigned int cpu, max, i;
max = last_context - first_context;
@@ -89,15 +99,22 @@ static unsigned int steal_context_smp(unsigned int id)
id = first_context;
continue;
}
- pr_devel("[%d] steal context %d from mm @%p\n",
- smp_processor_id(), id, mm);
+ pr_hardcont(" | steal %d from 0x%p", id, mm);
/* Mark this mm has having no context anymore */
mm->context.id = MMU_NO_CONTEXT;
- /* Mark it stale on all CPUs that used this mm */
- for_each_cpu(cpu, mm_cpumask(mm))
- __set_bit(id, stale_map[cpu]);
+ /* Mark it stale on all CPUs that used this mm. For threaded
+ * implementations, we set it on all threads on each core
+ * represented in the mask. A future implementation will use
+ * a core map instead but this will do for now.
+ */
+ for_each_cpu(cpu, mm_cpumask(mm)) {
+ for (i = cpu_first_thread_in_core(cpu);
+ i <= cpu_last_thread_in_core(cpu); i++)
+ __set_bit(id, stale_map[i]);
+ cpu = i - 1;
+ }
return id;
}
@@ -126,7 +143,7 @@ static unsigned int steal_context_up(unsigned int id)
/* Pick up the victim mm */
mm = context_mm[id];
- pr_devel("[%d] steal context %d from mm @%p\n", cpu, id, mm);
+ pr_hardcont(" | steal %d from 0x%p", id, mm);
/* Flush the TLB for that context */
local_flush_tlb_mm(mm);
@@ -179,19 +196,14 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
/* No lockless fast path .. yet */
spin_lock(&context_lock);
-#ifndef DEBUG_STEAL_ONLY
- pr_devel("[%d] activating context for mm @%p, active=%d, id=%d\n",
- cpu, next, next->context.active, next->context.id);
-#endif
+ pr_hard("[%d] activating context for mm @%p, active=%d, id=%d",
+ cpu, next, next->context.active, next->context.id);
#ifdef CONFIG_SMP
/* Mark us active and the previous one not anymore */
next->context.active++;
if (prev) {
-#ifndef DEBUG_STEAL_ONLY
- pr_devel(" old context %p active was: %d\n",
- prev, prev->context.active);
-#endif
+ pr_hardcont(" (old=0x%p a=%d)", prev, prev->context.active);
WARN_ON(prev->context.active < 1);
prev->context.active--;
}
@@ -201,8 +213,14 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
/* If we already have a valid assigned context, skip all that */
id = next->context.id;
- if (likely(id != MMU_NO_CONTEXT))
+ if (likely(id != MMU_NO_CONTEXT)) {
+#ifdef DEBUG_MAP_CONSISTENCY
+ if (context_mm[id] != next)
+ pr_err("MMU: mm 0x%p has id %d but context_mm[%d] says 0x%p\n",
+ next, id, id, context_mm[id]);
+#endif
goto ctxt_ok;
+ }
/* We really don't have a context, let's try to acquire one */
id = next_context;
@@ -235,11 +253,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
next_context = id + 1;
context_mm[id] = next;
next->context.id = id;
-
-#ifndef DEBUG_STEAL_ONLY
- pr_devel("[%d] picked up new id %d, nrf is now %d\n",
- cpu, id, nr_free_contexts);
-#endif
+ pr_hardcont(" | new id=%d,nrf=%d", id, nr_free_contexts);
context_check_map();
ctxt_ok:
@@ -248,15 +262,20 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
* local TLB for it and unmark it before we use it
*/
if (test_bit(id, stale_map[cpu])) {
- pr_devel("[%d] flushing stale context %d for mm @%p !\n",
- cpu, id, next);
+ pr_hardcont(" | stale flush %d [%d..%d]",
+ id, cpu_first_thread_in_core(cpu),
+ cpu_last_thread_in_core(cpu));
+
local_flush_tlb_mm(next);
/* XXX This clear should ultimately be part of local_flush_tlb_mm */
- __clear_bit(id, stale_map[cpu]);
+ for (cpu = cpu_first_thread_in_core(cpu);
+ cpu <= cpu_last_thread_in_core(cpu); cpu++)
+ __clear_bit(id, stale_map[cpu]);
}
/* Flick the MMU and release lock */
+ pr_hardcont(" -> %d\n", id);
set_context(id, next->pgd);
spin_unlock(&context_lock);
}
@@ -266,6 +285,8 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
*/
int init_new_context(struct task_struct *t, struct mm_struct *mm)
{
+ pr_hard("initing context for mm @%p\n", mm);
+
mm->context.id = MMU_NO_CONTEXT;
mm->context.active = 0;
@@ -305,7 +326,9 @@ static int __cpuinit mmu_context_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned int)(long)hcpu;
-
+#ifdef CONFIG_HOTPLUG_CPU
+ struct task_struct *p;
+#endif
/* We don't touch CPU 0 map, it's allocated at aboot and kept
* around forever
*/
@@ -324,8 +347,16 @@ static int __cpuinit mmu_context_cpu_notify(struct notifier_block *self,
pr_devel("MMU: Freeing stale context map for CPU %d\n", cpu);
kfree(stale_map[cpu]);
stale_map[cpu] = NULL;
- break;
-#endif
+
+ /* We also clear the cpu_vm_mask bits of CPUs going away */
+ read_lock(&tasklist_lock);
+ for_each_process(p) {
+ if (p->mm)
+ cpu_mask_clear_cpu(cpu, mm_cpumask(p->mm));
+ }
+ read_unlock(&tasklist_lock);
+ break;
+#endif /* CONFIG_HOTPLUG_CPU */
}
return NOTIFY_OK;
}
diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index ad2eb4d34dd..d908e75cc3b 100644
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -87,6 +87,12 @@ EXPORT_SYMBOL(local_flush_tlb_page);
static DEFINE_SPINLOCK(tlbivax_lock);
+static int mm_is_core_local(struct mm_struct *mm)
+{
+ return cpumask_subset(mm_cpumask(mm),
+ topology_thread_cpumask(smp_processor_id()));
+}
+
struct tlb_flush_param {
unsigned long addr;
unsigned int pid;
@@ -131,7 +137,7 @@ void flush_tlb_mm(struct mm_struct *mm)
pid = mm->context.id;
if (unlikely(pid == MMU_NO_CONTEXT))
goto no_context;
- if (!cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id()))) {
+ if (!mm_is_core_local(mm)) {
struct tlb_flush_param p = { .pid = pid };
/* Ignores smp_processor_id() even if set. */
smp_call_function_many(mm_cpumask(mm),
@@ -153,7 +159,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
if (unlikely(pid == MMU_NO_CONTEXT))
goto bail;
cpu_mask = mm_cpumask(vma->vm_mm);
- if (!cpumask_equal(cpu_mask, cpumask_of(smp_processor_id()))) {
+ if (!mm_is_core_local(mm)) {
/* If broadcast tlbivax is supported, use it */
if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) {
int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL);
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-25 05:39:58 +0000