These patches enable write cache part of raid5-cache. The journal part was released with kernel 4.4. The caching part uses same disk format of raid456 journal, and provides acceleration to writes. Write operations are committed (bio_endio) once the data is secured in journal. Reconstruct and RMW are postponed to reclaim path, which is (hopefully) not on the critical path. The changes are organized in 5 patches (details below). Current reclaim approach can be improved. So far it works OK in my tests with spinning disks as raid device and SSD as journal. I removed the patch for chunk_aligned_read in earlier RFC (http://marc.info/?l=linux-raid&m=146432700719277). But we may still need some optimizations later, especially for SSD raid devices. Thanks, Song Song Liu (5): r5cache: write part of r5cache r5cache: sysfs entry r5c_state r5cache: naive reclaim approach r5cache: r5c recovery r5cache: handle SYNC and FUA drivers/md/raid5-cache.c | 1299 ++++++++++++++++++++++++++++++++++++++++------ drivers/md/raid5.c | 185 ++++++- drivers/md/raid5.h | 30 +- 3 files changed, 1327 insertions(+), 187 deletions(-) -- 2.8.0.rc2 -- 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
