[PATCH v3 03/10] fprobe: Add nr_maxactive to specify rethook_node pool size
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: 2023-02-01 15:56:41
Also in:
lkml
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
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'. Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> --- include/linux/fprobe.h | 2 ++ kernel/trace/fprobe.c | 5 ++++- 2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/include/linux/fprobe.h b/include/linux/fprobe.h
index e0d4e6136249..678f741a7b33 100644
--- a/include/linux/fprobe.h
+++ b/include/linux/fprobe.h@@ -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);
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index fa25d09c9d57..f222848571f2 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c@@ -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;