[PATCH v7 1/4] tracing: Reset last_boot_info if ring buffer is reset
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STALE240d
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: 2026-02-09 09:25:34
Also in:
lkml
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Revision v7 of 10 in this series.
Revisions (10)
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Commit 32dc0042528d ("tracing: Reset last-boot buffers when reading
out all cpu buffers") resets the last_boot_info when user read out
all data via trace_pipe* files. But it is not reset when user
resets the buffer from other files. (e.g. write `trace` file)
Reset it when the corresponding ring buffer is reset too.
Fixes: 32dc0042528d ("tracing: Reset last-boot buffers when reading out all cpu buffers")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
Changes in v7:
- Remove unneeded update_last_data_if_empty() call from
tracing_snapshot_write() because snapshot is disabled on
persistent instances.
---
kernel/trace/trace.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 845b8a165daf..9e1cff78a1ca 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c@@ -4127,6 +4127,8 @@ static int tracing_single_release_tr(struct inode *inode, struct file *file) return single_release(inode, file); } +static bool update_last_data_if_empty(struct trace_array *tr); + static int tracing_open(struct inode *inode, struct file *file) { struct trace_array *tr = inode->i_private;
@@ -4151,6 +4153,8 @@ static int tracing_open(struct inode *inode, struct file *file) tracing_reset_online_cpus(trace_buf); else tracing_reset_cpu(trace_buf, cpu); + + update_last_data_if_empty(tr); } if (file->f_mode & FMODE_READ) {
@@ -5215,6 +5219,7 @@ tracing_set_trace_read(struct file *filp, char __user *ubuf, int tracer_init(struct tracer *t, struct trace_array *tr) { tracing_reset_online_cpus(&tr->array_buffer); + update_last_data_if_empty(tr); return t->init(tr); }
@@ -7028,6 +7033,7 @@ int tracing_set_clock(struct trace_array *tr, const char *clockstr) ring_buffer_set_clock(tr->snapshot_buffer.buffer, trace_clocks[i].func); tracing_reset_online_cpus(&tr->snapshot_buffer); #endif + update_last_data_if_empty(tr); if (tr->scratch && !(tr->flags & TRACE_ARRAY_FL_LAST_BOOT)) { struct trace_scratch *tscratch = tr->scratch;