Neil hello. 1. i have applied the common path according to http://www.spinics.net/lists/raid/msg11838.html as much as i can. it looks ok in terms of throughput. before i continue to a non common path ( step 3 ) i do not understand raid0_mergeable_bvec entirely. as i understand the code checks alignment . i made a version for this purpose which looks like that: static int raid5_mergeable_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *biovec) { mddev_t *mddev = q->queuedata; sector_t sector=bio->bi_sector+get_start_sect(bio->bi_bdev); int max; unsigned int chunk_sectors = mddev->chunk_size >> 9; unsigned int bio_sectors = bio->bi_size >> 9; max=(chunk_sectors-((sector&(chunk_sectors-1))+bio_sectors))<<9; if (max < 0){ printk("handle_aligned_read not aligned %d %d %d %lld\n",max,chunk_sectors,bio_sectors,sector); return -1; // Is bigger than one chunk size } // printk("handle_aligned_read aligned %d %d %d %lld\n",max,chunk_sectors,bio_sectors,sector); return max; } Questions: 1.1 why did you drop the max=0 case ? 1.2 what these lines mean ? do i need it ? if (max <= biovec->bv_len && bio_sectors == 0) return biovec->bv_len; else return max; } thank you Raz - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
