kernel/linux.git/tools/tracing/rtla/src/common.c, branch v7.0-rc7

rtla: Make stop_tracing variable volatile

2026-01-07T14:57:55+00:00

The stop_tracing global variable is accessed from both the signal handler context and the main program flow without synchronization. This creates a potential race condition where compiler optimizations could cache the variable value in registers, preventing the signal handler's updates from being visible to other parts of the program. Add the volatile qualifier to stop_tracing in both common.c and common.h to ensure all accesses to this variable bypass compiler optimizations and read directly from memory. This guarantees that when the signal handler sets stop_tracing, the change is immediately visible to the main program loop, preventing potential hangs or delayed shutdown when termination signals are received. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-16-wander@redhat.com Signed-off-by: Tomas Glozar

tools/rtla: Consolidate -H/--house-keeping option parsing

2026-01-07T14:57:17+00:00

Each rtla tool duplicates parsing of -H/--house-keeping. Migrate the option parsing from individual tools to the common_parse_options(). Signed-off-by: Costa Shulyupin Link: https://lore.kernel.org/r/20251209100047.2692515-8-costa.shul@redhat.com Signed-off-by: Tomas Glozar

tools/rtla: Consolidate -P/--priority option parsing

2026-01-07T14:57:17+00:00

Each rtla tool duplicates parsing of -P/--priority. Migrate the option parsing from individual tools to the common_parse_options(). Signed-off-by: Costa Shulyupin Link: https://lore.kernel.org/r/20251209100047.2692515-7-costa.shul@redhat.com Signed-off-by: Tomas Glozar

tools/rtla: Consolidate -e/--event option parsing

2026-01-07T14:57:17+00:00

Each rtla tool duplicates parsing of -e/--event. Migrate the option parsing from individual tools to the common_parse_options(). Signed-off-by: Costa Shulyupin Link: https://lore.kernel.org/r/20251209100047.2692515-6-costa.shul@redhat.com Signed-off-by: Tomas Glozar

tools/rtla: Consolidate -d/--duration option parsing

2026-01-07T14:57:17+00:00

Each rtla tool duplicates parsing of -d/--duration. Migrate the option parsing from individual tools to the common_parse_options(). Signed-off-by: Costa Shulyupin Link: https://lore.kernel.org/r/20251209100047.2692515-5-costa.shul@redhat.com Signed-off-by: Tomas Glozar

tools/rtla: Consolidate -D/--debug option parsing

2026-01-07T14:57:17+00:00

Each rtla tool duplicates parsing of -D/--debug. Migrate the option parsing from individual tools to the common_parse_options(). Signed-off-by: Costa Shulyupin Link: https://lore.kernel.org/r/20251209100047.2692515-4-costa.shul@redhat.com Signed-off-by: Tomas Glozar

tools/rtla: Consolidate -C/--cgroup option parsing

2026-01-07T14:57:17+00:00

Each rtla tool duplicates parsing of -C/--cgroup. Migrate the option parsing from individual tools to the common_parse_options(). Signed-off-by: Costa Shulyupin Link: https://lore.kernel.org/r/20251209100047.2692515-3-costa.shul@redhat.com Signed-off-by: Tomas Glozar

tools/rtla: Consolidate -c/--cpus option parsing

2026-01-07T14:57:16+00:00

Each rtla tool duplicates parsing of -c/--cpus. Migrate the option parsing from individual tools to the common_parse_options(). Signed-off-by: Costa Shulyupin Link: https://lore.kernel.org/r/20251209100047.2692515-2-costa.shul@redhat.com Signed-off-by: Tomas Glozar

tools/rtla: Add common_parse_options()

2026-01-07T14:57:16+00:00

Each rtla tool duplicates parsing of many common options. This creates maintenance overhead and risks inconsistencies when updating these options. Add common_parse_options() to centralize parsing of options used across all tools. Common options to be migrated in future patches. Changes since v1: - restore opterr Signed-off-by: Costa Shulyupin Link: https://lore.kernel.org/r/20251209100047.2692515-1-costa.shul@redhat.com Signed-off-by: Tomas Glozar

tools/rtla: Add common_usage()

2026-01-07T14:57:15+00:00

The rtla tools have significant code quadruplication in their usage functions. Each tool implements its own version of the same help text formatting and option descriptions, leading to maintenance overhead and inconsistencies. Documentation/tools/rtla/common_options.rst lists 14 common options. Add common_usage() infrastructure to consolidate help formatting. Subsequent patches will extend this to handle other common options. The refactored output is almost identical to the original, with the following changes: - add square brackets to specify optionality: `usage: [rtla] ...` - remove `-q` from timerlat hist because hist tools don't support it - minor spacing Signed-off-by: Costa Shulyupin Link: https://lore.kernel.org/r/20251124063204.845425-1-costa.shul@redhat.com Signed-off-by: Tomas Glozar