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| author |   Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2025-02-19 00:09:08 +0900 |
|---|---|---|
| committer |   Steven Rostedt (Google) <rostedt@goodmis.org> | 2025-03-28 08:39:28 -0400 |
| commit | fb6d03238e35f96cc1d6a5411ee1d684221d1c39 (patch) | |
| tree | b338b7283d9bbd5a3f8122b4f7af3fe73637c1c3 /kernel/trace/trace.h | |
| parent | mm/memblock: Add reserved memory release function (diff) | |
| download | wireguard-linux-fb6d03238e35f96cc1d6a5411ee1d684221d1c39.tar.xz wireguard-linux-fb6d03238e35f96cc1d6a5411ee1d684221d1c39.zip | |
tracing: Freeable reserved ring buffer
Make the ring buffer on reserved memory to be freeable. This allows us
to free the trace instance on the reserved memory without changing
cmdline and rebooting. Even if we can not change the kernel cmdline
for security reason, we can release the reserved memory for the ring
buffer as free (available) memory.
For example, boot kernel with reserved memory;
"reserve_mem=20M:2M:trace trace_instance=boot_mapped^traceoff@trace"
~ # free
total used free shared buff/cache available
Mem: 1995548 50544 1927568 14964 17436 1911480
Swap: 0 0 0
~ # rmdir /sys/kernel/tracing/instances/boot_mapped/
[ 23.704023] Freeing reserve_mem:trace memory: 20476K
~ # free
total used free shared buff/cache available
Mem: 2016024 41844 1956740 14968 17440 1940572
Swap: 0 0 0
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Link: https://lore.kernel.org/173989134814.230693.18199312930337815629.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to '')
| -rw-r--r-- | kernel/trace/trace.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 90493220c362..0d6efb8a1179 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -348,6 +348,7 @@ struct trace_array { unsigned int mapped; unsigned long range_addr_start; unsigned long range_addr_size; + char *range_name; long text_delta; void *scratch; /* pointer in persistent memory */ int scratch_size; |