• Steven Rostedt's avatar
    ftrace: trace_entries to dynamically change trace buffer size · a98a3c3f
    Steven Rostedt authored
    This patch adds /debug/tracing/trace_entries that allows users to
    see as well as modify the number of trace entries the buffers hold.
    
    The number of entries only increments in ENTRIES_PER_PAGE which is
    calculated by the size of an entry with the number of entries that
    can fit in a page. The user does not need to use an exact size, but
    the entries will be rounded to one of the increments.
    
    Trying to set the entries to 0 will return with -EINVAL.
    
    To avoid race conditions, the modification of the buffer size can only
    be done when tracing is completely disabled (current_tracer == none).
    A info message will be printed if a user tries to modify the buffer size
    when not set to none.
    Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    a98a3c3f
trace.c 61.6 KB