On 1/10/19 4:12 PM, Jeff Moyer wrote: > Jens Axboe <axboe@xxxxxxxxx> writes: > >> Add hint on whether a read was served out of the page cache, or if it >> hit media. This is useful for buffered async IO, O_DIRECT reads would >> never have this set (for obvious reasons). >> >> If the read hit page cache, cqe->flags will have IOCQE_FLAG_CACHEHIT >> set. > > We may want to hold off on this one until the whole mincore/RWF_NOWAIT > debate is sorted. [1] Definitely, it's why it's separate and at the end of the series. But in reality, this doesn't leak anything that timing doesn't already tell you. So it's kind of a moot point. -- Jens Axboe