On 2021/3/24 12:04, Namhyung Kim wrote:
On Wed, Mar 24, 2021 at 12:47 PM Like Xu <like...@linux.intel.com> wrote:
Hi Namhyung,
On 2021/3/24 9:32, Namhyung Kim wrote:
Hello,
On Mon, Mar 22, 2021 at 3:14 PM Like Xu <like...@linux.intel.com> wrote:
+void reserve_lbr_buffers(struct perf_event *event)
+{
+ struct kmem_cache *kmem_cache = x86_get_pmu()->task_ctx_cache;
+ struct cpu_hw_events *cpuc;
+ int cpu;
+
+ if (!static_cpu_has(X86_FEATURE_ARCH_LBR))
+ return;
+
+ for_each_possible_cpu(cpu) {
+ cpuc = per_cpu_ptr(&cpu_hw_events, cpu);
+ if (kmem_cache && !cpuc->lbr_xsave && !event->attr.precise_ip)
+ cpuc->lbr_xsave = kmem_cache_alloc(kmem_cache,
GFP_KERNEL);
+ }
+}
I think we should use kmem_cache_alloc_node().
"kmem_cache_alloc_node - Allocate an object on the specified node"
The reserve_lbr_buffers() is called in __x86_pmu_event_init().
When the LBR perf_event is scheduled to another node, it seems
that we will not call init() and allocate again.
Do you mean use kmem_cache_alloc_node() for each numa_nodes_parsed ?
I assume cpuc->lbr_xsave will be accessed for that cpu only.
Then it needs to allocate it in the node that cpu belongs to.
Something like below..
cpuc->lbr_xsave = kmem_cache_alloc_node(kmem_cache, GFP_KERNEL,
cpu_to_node(cpu));
Thanks, it helps and I will apply it in the next version.
Thanks,
Namhyung
