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] Cheers, Jeff [1] https://lore.kernel.org/lkml/20190109022430.GE27534@dastard/