| Message ID | 1557480663-16759-2-git-send-email-suzuki.poulose@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: Do not call smp_processor_id from preemptible contexts | expand |
Hi Suzuki, On 10/05/2019 10:31, Suzuki K Poulose 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 > > 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..cae9d8a 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); If cpu == -1 represents a "don't care" scenario, it might be clearer to just use NUMA_NO_NODE instead, and let the allocator handle it. Robin. > > etr_perf = kzalloc_node(sizeof(*etr_perf), GFP_KERNEL, node); > if (!etr_perf) >
Hi Robin, On 10/05/2019 11:38, Robin Murphy wrote: > Hi Suzuki, > > On 10/05/2019 10:31, Suzuki K Poulose 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 : > >> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c >> index 793639f..cae9d8a 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); > > If cpu == -1 represents a "don't care" scenario, it might be clearer to > just use NUMA_NO_NODE instead, and let the allocator handle it. Thanks for the suggestion, will use that instead Cheers Suzuki
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 793639f..cae9d8a 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); etr_perf = kzalloc_node(sizeof(*etr_perf), GFP_KERNEL, node); if (!etr_perf)
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 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(-)