[for-next,03/25] fprobe: Add nr_maxactive to specify rethook_node pool size
Commit Message
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Add nr_maxactive to specify rethook_node pool size. This means
the maximum number of actively running target functions concurrently
for probing by exit_handler. Note that if the running function is
preempted or sleep, it is still counted as 'active'.
Link: https://lkml.kernel.org/r/167526697917.433354.17779774988245113106.stgit@mhiramat.roam.corp.google.com
Cc: Florent Revest <revest@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
include/linux/fprobe.h | 2 ++
kernel/trace/fprobe.c | 5 ++++-
2 files changed, 6 insertions(+), 1 deletion(-)
@@ -14,6 +14,7 @@
* @flags: The status flag.
* @rethook: The rethook data structure. (internal data)
* @entry_data_size: The private data storage size.
+ * @nr_maxactive: The max number of active functions.
* @entry_handler: The callback function for function entry.
* @exit_handler: The callback function for function exit.
*/
@@ -31,6 +32,7 @@ struct fprobe {
unsigned int flags;
struct rethook *rethook;
size_t entry_data_size;
+ int nr_maxactive;
void (*entry_handler)(struct fprobe *fp, unsigned long entry_ip,
struct pt_regs *regs, void *entry_data);
@@ -143,7 +143,10 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
}
/* Initialize rethook if needed */
- size = num * num_possible_cpus() * 2;
+ if (fp->nr_maxactive)
+ size = fp->nr_maxactive;
+ else
+ size = num * num_possible_cpus() * 2;
if (size < 0)
return -E2BIG;