[PATCH tip/core/rcu 11/30] refperf: Dynamically allocate thread-summary output buffer

paulmck
2020-06-23T00:32:04Z

Currently, the buffer used to accumulate the thread-summary output is
fixed size, which will cause problems if someone decides to run on a large
number of PCUs. This commit therefore dynamically allocates this buffer.

[ paulmck: Fix memory allocation as suggested by KASAN. ]
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/refperf.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/refperf.c b/kernel/rcu/refperf.c
index 75b9cce..fc940e3 100644
--- a/kernel/rcu/refperf.c
+++ b/kernel/rcu/refperf.c
@@ -301,9 +301,12 @@ u64 process_durations(int n)
int i;
struct reader_task *rt;
char buf1[64];
- char buf[512];
+ char *buf;
u64 sum = 0;

+ buf = kmalloc(128 + nreaders * 32, GFP_KERNEL);
+ if (!buf)
+ return 0;
buf[0] = 0;
sprintf(buf, "Experiment #%d (Format: <THREAD-NUM>:<Total loop time in ns>)",
exp_idx);
@@ -322,6 +325,7 @@ u64 process_durations(int n)

PERFOUT("%s\n", buf);

+ kfree(buf);
return sum;
}

--
2.9.5