2013/03/30 2:15, Jan Kara wrote:
Sorry for not getting to you earlier. So we agree in our analysis. Do you agree with the attached patch? Does it help your workload?
According to your two patches, direct I/O works as the following steps: 1. add sdio->cur_page to sdio->bio by dio_new_bio() or dio_bio_add_page() 2. submit sdio->bio if sdio->boudary is set 3. set the curret page to sdio->cur_page in submit_page_section() Only one page is submitted separately because of submitting bio before step 3. For example, we write 52KB data with O_DIRECT, it is ideal that filesystem submits a bio twice (48KB and 4KB). However, after applying your two patches, 52KB data is split into three bios (44KB, 4KB and 4KB). Regards, Kazuya Mio -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
