Hi Suzuki,
On Fri, 3 May 2019 at 10:04, Suzuki K Poulose suzuki.poulose@arm.com wrote:
Instead of using smp_processor_id() to figure out the node, use the numa_node_id() for the current CPU node to avoid splats like :
BUG: using smp_processor_id() in preemptible [00000000] code: perf/1743 caller is alloc_etr_buf.isra.6+0x80/0xa0 CPU: 1 PID: 1743 Comm: perf Not tainted 5.1.0-rc6-147786-g116841e #344 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Feb 1 2019 Call trace: dump_backtrace+0x0/0x150 show_stack+0x14/0x20 dump_stack+0x9c/0xc4 debug_smp_processor_id+0x10c/0x110 alloc_etr_buf.isra.6+0x80/0xa0 tmc_alloc_etr_buffer+0x12c/0x1f0 etm_setup_aux+0x1c4/0x230 rb_alloc_aux+0x1b8/0x2b8 perf_mmap+0x35c/0x478 mmap_region+0x34c/0x4f0 do_mmap+0x2d8/0x418 vm_mmap_pgoff+0xd0/0xf8 ksys_mmap_pgoff+0x88/0xf8 __arm64_sys_mmap+0x28/0x38 el0_svc_handler+0xd8/0x138 el0_svc+0x8/0xc
That is very interesting...
Fixes: 855ab61c16bf70b646 ("coresight: tmc-etr: Refactor function tmc_etr_setup_perf_buf()") Cc: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com
drivers/hwtracing/coresight/coresight-tmc-etr.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 793639f..74578bd 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1323,13 +1323,11 @@ static struct etr_perf_buffer * tmc_etr_setup_perf_buf(struct tmc_drvdata *drvdata, struct perf_event *event, int nr_pages, void **pages, bool snapshot) {
int node, cpu = event->cpu;
int node; struct etr_buf *etr_buf; struct etr_perf_buffer *etr_perf;
if (cpu == -1)cpu = smp_processor_id();node = cpu_to_node(cpu);
node = (event->cpu == -1)? numa_node_id() : cpu_to_node(event->cpu);
Seems to me using numa_node_id() simply circumvent function debug_smp_processor_id() and using get_cpu() and put_cpu() would be more appropriate. But I'll trust the NUMA people have thought about this long before me. Would you mind sending another revision that fix the same code for ETB and ETF?
Thanks, Mathieu
etr_perf = kzalloc_node(sizeof(*etr_perf), GFP_KERNEL, node); if (!etr_perf)-- 2.7.4