Commit 7e267a8c authored by Dan Williams's avatar Dan Williams

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 <toshi.kani@hpe.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 0c27af60
......@@ -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);
......
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