On Mon, 2010-05-17 at 16:25 +0200, Stephane Eranian wrote:
> > Right, but I think the default of inherit is right, and once you do that
> > you basically have to do the per-task-per-cpu thing, otherwise your
> > fancy 16-way will start spending most of its time in cacheline bounces.
> >
> In that case, don't you think you should also ensure that the buffer is
> allocated on the NUMA node of the designated per-thread-per-cpu?
> I don't think it is the case today.
Yeah, something like the below ought to do I guess..
Almost-Signed-off-by: Peter Zijlstra <a.p.zijls...@chello.nl>
---
kernel/perf_event.c | 17 +++++++++++++++--
1 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 9dbe8cd..85e2d32 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2288,6 +2288,19 @@ perf_mmap_to_page(struct perf_mmap_data *data, unsigned
long pgoff)
return virt_to_page(data->data_pages[pgoff - 1]);
}
+static void *perf_mmap_alloc_page(int cpu)
+{
+ struct page *page;
+ int node;
+
+ node = (cpu == -1) ? cpu : cpu_to_node(cpu);
+ page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
+ if (!page)
+ return NULL;
+
+ return page_address(page);
+}
+
static struct perf_mmap_data *
perf_mmap_data_alloc(struct perf_event *event, int nr_pages)
{
@@ -2304,12 +2317,12 @@ perf_mmap_data_alloc(struct perf_event *event, int
nr_pages)
if (!data)
goto fail;
- data->user_page = (void *)get_zeroed_page(GFP_KERNEL);
+ data->user_page = perf_mmap_alloc_page(event->cpu);
if (!data->user_page)
goto fail_user_page;
for (i = 0; i < nr_pages; i++) {
- data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL);
+ data->data_pages[i] = perf_mmap_alloc_page(event->cpu);
if (!data->data_pages[i])
goto fail_data_pages;
}
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