From 2cddfc2e8fc78c13b0f5286ea5dd48cdf527ad41 Mon Sep 17 00:00:00 2001 From: Aaron Tomlin Date: Fri, 26 Dec 2025 11:07:24 -0500 Subject: 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 Signed-off-by: Steven Rostedt (Google) --- Documentation/trace/ftrace.rst | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'Documentation/trace') diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index d1f313a5f4ad..639f4d95732f 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -1290,6 +1290,15 @@ Here are the available options: This will be useful if you want to find out which hashed value is corresponding to the real value in trace log. + bitmask-list + When enabled, bitmasks are displayed as a human-readable list of + ranges (e.g., 0,2-5,7) using the printk "%*pbl" format specifier. + When disabled (the default), bitmasks are displayed in the + traditional hexadecimal bitmap representation. The list format is + particularly useful for tracing CPU masks and other large bitmasks + where individual bit positions are more meaningful than their + hexadecimal encoding. + record-cmd When any event or tracer is enabled, a hook is enabled in the sched_switch trace point to fill comm cache -- cgit v1.2.3