We have recently turned on ftrace-dump-on-oops for i915's CI and an issue we have encountered is that the trace buffer size greatly exceeds the pstore capabilities; we get the tail of the oops but not the introduction. Currently the global buffer size is controllable on the cmdline, but at the request of our CI sysadmin, we would like to add a control to the Kconfig as well. The rationale being the cmdline carries the temporary hacks that we want to eradicate, and we want to track the permanent configuration in .config. I have kept the Kconfig option hidden from the user as the default should suffice for the majority of users; reserving the configuration for those that eschew the cmdline option. Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Steven Rostedt <srostedt@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Tomi Sarvela <tomi.p.sarvela@xxxxxxxxx> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> --- kernel/trace/Kconfig | 6 ++++++ kernel/trace/trace.c | 4 +--- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 434c840e2d82..d5b3b13a66b5 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -100,6 +100,12 @@ config TRACING select EVENT_TRACING select TRACE_CLOCK +config GLOBAL_TRACE_BUF_SIZE + int + range 0 4194034 + default 1441792 # 16384 * 88 (sizeof(struct print_entry)) + depends on TRACING + config GENERIC_TRACER bool select TRACING diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 752e5daf0896..b1e6ebd96da3 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -614,9 +614,7 @@ int tracing_is_enabled(void) * to not have to wait for all that output. Anyway this can be * boot time and run time configurable. */ -#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ - -static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; +static unsigned long trace_buf_size = CONFIG_GLOBAL_TRACE_BUF_SIZE; /* trace_types holds a link list of available tracers. */ static struct tracer *trace_types __read_mostly; -- 2.15.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
