On 06/23/2018 12:22 PM, Douglas Gilbert wrote:
Add likely() and unlikely() hints to conditionals on or near the fastpath. Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx> Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx> Reviewed-by: Bart Van Assche <bart.vanassche@xxxxxxx> --- A reviewer wanted any performance improvement (or otherwise) quantified. The improvement was so small, that ftrace ignored it. Inline timing code suggests the improvement from this whole patchset is around 7 nanoseconds per invocation (tested on a Lenovo X270 (i5-7200U)). Not exactly huge. Another win might be the smaller size of scsi_io_completion() after the refactoring; this should allow more other code to fit in the instruction cache.
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx> Cheers, Hannes
