[PATCH][RFC] nvdimm: pmem: always flush nvdimm for write request

flush nvdimm for write request can speed the random write, give about 20% performance The below is result of fio 4k random write nvdimm as /dev/pmem0 Before: Jobs: 32 (f=32): [W(32)][14.2%][w=1884MiB/s][w=482k IOPS][eta 01m:43s] After: Jobs: 32 (f=32): [W(32)][8.3%][w=2378MiB/s][w=609k IOPS][eta 01m:50s] This makes sure that the newly written data is durable too Co-developed-by: Liang ZhiCheng <liangzhicheng(a)baidu.com&gt; Signed-off-by: Liang ZhiCheng <liangzhicheng(a)baidu.com&gt; Signed-off-by: Li RongQing <lirongqing(a)baidu.com&gt; --- This test is done on intel AEP drivers/nvdimm/pmem.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 1d432c5ed..9f8f25880 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -197,6 +197,7 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) unsigned long start; struct bio_vec bvec; struct bvec_iter iter; + unsigned int op = bio_op(bio); struct pmem_device *pmem = q->queuedata; struct nd_region *nd_region = to_region(pmem); @@ -206,7 +207,7 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) do_acct = nd_iostat_start(bio, &start); bio_for_each_segment(bvec, bio, iter) { rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, - bvec.bv_offset, bio_op(bio), iter.bi_sector); + bvec.bv_offset, op, iter.bi_sector); if (rc) { bio->bi_status = rc; break; @@ -215,7 +216,7 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) if (do_acct) nd_iostat_end(bio, start); - if (bio->bi_opf & REQ_FUA) + if (bio->bi_opf & REQ_FUA || op_is_write(op)) nvdimm_flush(nd_region); bio_endio(bio); -- 2.16.2