diff options
| author | Aaron Tomlin <atomlin@atomlin.com> | 2025-12-26 11:07:24 -0500 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2026-01-26 17:00:50 -0500 |
| commit | 2cddfc2e8fc78c13b0f5286ea5dd48cdf527ad41 (patch) | |
| tree | 4ebdba4d9ca44cee4a1cc23a9867770522875cb1 /kernel/trace/trace_seq.c | |
| parent | a4e0ea0e10a262fb6f1ad55a8a9d203bad776678 (diff) | |
tracing: Add bitmask-list option for human-readable bitmask display
Add support for displaying bitmasks in human-readable list format (e.g.,
0,2-5,7) in addition to the default hexadecimal bitmap representation.
This is particularly useful when tracing CPU masks and other large
bitmasks where individual bit positions are more meaningful than their
hexadecimal encoding.
When the "bitmask-list" option is enabled, the printk "%*pbl" format
specifier is used to render bitmasks as comma-separated ranges, making
trace output easier to interpret for complex CPU configurations and
large bitmask values.
Link: https://patch.msgid.link/20251226160724.2246493-2-atomlin@atomlin.com
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_seq.c')
| -rw-r--r-- | kernel/trace/trace_seq.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c index 32684ef4fb9d..85f6f10d107f 100644 --- a/kernel/trace/trace_seq.c +++ b/kernel/trace/trace_seq.c @@ -106,7 +106,7 @@ EXPORT_SYMBOL_GPL(trace_seq_printf); * Writes a ASCII representation of a bitmask string into @s. */ void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp, - int nmaskbits) + int nmaskbits) { unsigned int save_len = s->seq.len; @@ -125,6 +125,33 @@ void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp, EXPORT_SYMBOL_GPL(trace_seq_bitmask); /** + * trace_seq_bitmask_list - write a bitmask array in its list representation + * @s: trace sequence descriptor + * @maskp: points to an array of unsigned longs that represent a bitmask + * @nmaskbits: The number of bits that are valid in @maskp + * + * Writes a list representation (e.g., 0-3,5-7) of a bitmask string into @s. + */ +void trace_seq_bitmask_list(struct trace_seq *s, const unsigned long *maskp, + int nmaskbits) +{ + unsigned int save_len = s->seq.len; + + if (s->full) + return; + + __trace_seq_init(s); + + seq_buf_printf(&s->seq, "%*pbl", nmaskbits, maskp); + + if (unlikely(seq_buf_has_overflowed(&s->seq))) { + s->seq.len = save_len; + s->full = 1; + } +} +EXPORT_SYMBOL_GPL(trace_seq_bitmask_list); + +/** * trace_seq_vprintf - sequence printing of trace information * @s: trace sequence descriptor * @fmt: printf format string |