From 7e267a8c790edfde9b697cbe944ee566f41219c3 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 1 Jun 2016 20:48:15 -0700 Subject: libnvdimm, pmem: use REQ_FUA, REQ_FLUSH for nvdimm_flush() Given that nvdimm_flush() has higher overhead than wmb_pmem() (pointer chasing through nd_region), and that we otherwise assume a platform has ADR capability when flush hints are not present, move nvdimm_flush() to REQ_FLUSH context. Note that we still arrange for nvdimm_flush() to be called even in the ADR case. We need at least once wmb() fence to push buffered writes in the cpu out to the ADR protected domain. Cc: Toshi Kani Cc: Ross Zwisler Signed-off-by: Dan Williams --- drivers/nvdimm/pmem.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) (limited to 'drivers/nvdimm') diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index e303655f243e..9d9c1beef020 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -113,6 +113,11 @@ static int pmem_do_bvec(struct pmem_device *pmem, struct page *page, return rc; } +/* account for REQ_FLUSH rename, replace with REQ_PREFLUSH after v4.8-rc1 */ +#ifndef REQ_FLUSH +#define REQ_FLUSH REQ_PREFLUSH +#endif + static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) { int rc = 0; @@ -121,6 +126,10 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) struct bio_vec bvec; struct bvec_iter iter; struct pmem_device *pmem = q->queuedata; + struct nd_region *nd_region = to_region(pmem); + + if (bio->bi_rw & REQ_FLUSH) + nvdimm_flush(nd_region); do_acct = nd_iostat_start(bio, &start); bio_for_each_segment(bvec, bio, iter) { @@ -135,8 +144,8 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) if (do_acct) nd_iostat_end(bio, start); - if (bio_data_dir(bio)) - nvdimm_flush(to_region(pmem)); + if (bio->bi_rw & REQ_FUA) + nvdimm_flush(nd_region); bio_endio(bio); return BLK_QC_T_NONE; @@ -149,8 +158,6 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector, int rc; rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, rw, sector); - if (rw & WRITE) - nvdimm_flush(to_region(pmem)); /* * The ->rw_page interface is subtle and tricky. The core @@ -279,6 +286,7 @@ static int pmem_attach_disk(struct device *dev, return PTR_ERR(addr); pmem->virt_addr = (void __pmem *) addr; + blk_queue_write_cache(q, true, true); blk_queue_make_request(q, pmem_make_request); blk_queue_physical_block_size(q, PAGE_SIZE); blk_queue_max_hw_sectors(q, UINT_MAX); -- cgit v1.2.3-59-g8ed1b