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From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, coresight@lists.linaro.org,
	mathieu.poirier@linaro.org,
	Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH 1/2] coresight: Do not call smp_processor_id() from preemptible
Date: Fri,  3 May 2019 17:04:18 +0100	[thread overview]
Message-ID: <1556899459-27785-1-git-send-email-suzuki.poulose@arm.com> (raw)

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..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);
 
 	etr_perf = kzalloc_node(sizeof(*etr_perf), GFP_KERNEL, node);
 	if (!etr_perf)
-- 
2.7.4


             reply	other threads:[~2019-05-03 16:04 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-03 16:04 Suzuki K Poulose [this message]
2019-05-03 16:04 ` [PATCH 2/2] coresight: alloc_perf_buf: Do not call smp_processor_id " Suzuki K Poulose
2019-05-08 16:39 ` [PATCH 1/2] coresight: Do not call smp_processor_id() " Mathieu Poirier
2019-05-08 16:43   ` Suzuki K Poulose

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