[PATCH v2] trace/pid_list: Change gfp flags in pid_list_fill_irq()

[Levi Yun]

From: "levi.yun" <yeoreum....@arm.com>

pid_list_fill_irq() runs via irq_work.
When CONFIG_PREEMPT_RT is disabled, it would run in irq_context.
so it shouldn't sleep while memory allocation.

Change gfp flags from GFP_KERNEL to GFP_NOWAIT to prevent sleep in
irq_work.

This change wouldn't impact functionality in practice because the worst-size
is 2K.

Signed-off-by: levi.yun <yeoreum....@arm.com>
---
 kernel/trace/pid_list.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/pid_list.c b/kernel/trace/pid_list.c
index 95106d02b32d..85de221c0b6f 100644
--- a/kernel/trace/pid_list.c
+++ b/kernel/trace/pid_list.c
@@ -354,7 +354,7 @@ static void pid_list_refill_irq(struct irq_work *iwork)
        while (upper_count-- > 0) {
                union upper_chunk *chunk;

-               chunk = kzalloc(sizeof(*chunk), GFP_KERNEL);
+               chunk = kzalloc(sizeof(*chunk), GFP_NOWAIT);
                if (!chunk)
                        break;
                *upper_next = chunk;
@@ -365,7 +365,7 @@ static void pid_list_refill_irq(struct irq_work *iwork)
        while (lower_count-- > 0) {
                union lower_chunk *chunk;

-               chunk = kzalloc(sizeof(*chunk), GFP_KERNEL);
+               chunk = kzalloc(sizeof(*chunk), GFP_NOWAIT);
                if (!chunk)
                        break;
                *lower_next = chunk;
--
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}