• Alexander Shishkin's avatar
    perf: Add wakeup watermark control to the AUX area · 1a594131
    Alexander Shishkin authored
    When AUX area gets a certain amount of new data, we want to wake up
    userspace to collect it. This adds a new control to specify how much
    data will cause a wakeup. This is then passed down to pmu drivers via
    output handle's "wakeup" field, so that the driver can find the nearest
    point where it can generate an interrupt.
    
    We repurpose __reserved_2 in the event attribute for this, even though
    it was never checked to be zero before, aux_watermark will only matter
    for new AUX-aware code, so the old code should still be fine.
    Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
    Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Kaixu Xia <kaixu.xia@linaro.org>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Mike Galbraith <efault@gmx.de>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Robert Richter <rric@kernel.org>
    Cc: Stephane Eranian <eranian@google.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: acme@infradead.org
    Cc: adrian.hunter@intel.com
    Cc: kan.liang@intel.com
    Cc: markus.t.metzger@intel.com
    Cc: mathieu.poirier@linaro.org
    Link: http://lkml.kernel.org/r/1421237903-181015-10-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    1a594131
ring_buffer.c 16.8 KB