[patch 070/119] block, THP: make block_device_operations.rw_page support THP

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Huang Ying <ying.huang@xxxxxxxxx>
Subject: block, THP: make block_device_operations.rw_page support THP

The .rw_page in struct block_device_operations is used by the swap
subsystem to read/write the page contents from/into the corresponding swap
slot in the swap device.  To support the THP (Transparent Huge Page) swap
optimization, the .rw_page is enhanced to support to read/write THP if
possible.

Link: http://lkml.kernel.org/r/20170724051840.2309-6-ying.huang@xxxxxxxxx
Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Reviewed-by: Ross Zwisler <ross.zwisler@xxxxxxxxx> [for brd.c, zram_drv.c, pmem.c]
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Vishal L Verma <vishal.l.verma@xxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Shaohua Li <shli@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 drivers/block/brd.c           |    6 ++++-
 drivers/block/zram/zram_drv.c |    2 +
 drivers/nvdimm/btt.c          |    4 ++-
 drivers/nvdimm/pmem.c         |   37 ++++++++++++++++++++++++--------
 4 files changed, 38 insertions(+), 11 deletions(-)

diff -puN drivers/block/brd.c~block-thp-make-block_device_operationsrw_page-support-thp drivers/block/brd.c
--- a/drivers/block/brd.c~block-thp-make-block_device_operationsrw_page-support-thp
+++ a/drivers/block/brd.c
@@ -326,7 +326,11 @@ static int brd_rw_page(struct block_devi
 		       struct page *page, bool is_write)
 {
 	struct brd_device *brd = bdev->bd_disk->private_data;
-	int err = brd_do_bvec(brd, page, PAGE_SIZE, 0, is_write, sector);
+	int err;
+
+	if (PageTransHuge(page))
+		return -ENOTSUPP;
+	err = brd_do_bvec(brd, page, PAGE_SIZE, 0, is_write, sector);
 	page_endio(page, is_write, err);
 	return err;
 }
diff -puN drivers/block/zram/zram_drv.c~block-thp-make-block_device_operationsrw_page-support-thp drivers/block/zram/zram_drv.c
--- a/drivers/block/zram/zram_drv.c~block-thp-make-block_device_operationsrw_page-support-thp
+++ a/drivers/block/zram/zram_drv.c
@@ -1285,6 +1285,8 @@ static int zram_rw_page(struct block_dev
 	struct zram *zram;
 	struct bio_vec bv;
 
+	if (PageTransHuge(page))
+		return -ENOTSUPP;
 	zram = bdev->bd_disk->private_data;
 
 	if (!valid_io_request(zram, sector, PAGE_SIZE)) {
diff -puN drivers/nvdimm/btt.c~block-thp-make-block_device_operationsrw_page-support-thp drivers/nvdimm/btt.c
--- a/drivers/nvdimm/btt.c~block-thp-make-block_device_operationsrw_page-support-thp
+++ a/drivers/nvdimm/btt.c
@@ -1241,8 +1241,10 @@ static int btt_rw_page(struct block_devi
 {
 	struct btt *btt = bdev->bd_disk->private_data;
 	int rc;
+	unsigned int len;
 
-	rc = btt_do_bvec(btt, NULL, page, PAGE_SIZE, 0, is_write, sector);
+	len = hpage_nr_pages(page) * PAGE_SIZE;
+	rc = btt_do_bvec(btt, NULL, page, len, 0, is_write, sector);
 	if (rc == 0)
 		page_endio(page, is_write, 0);
 
diff -puN drivers/nvdimm/pmem.c~block-thp-make-block_device_operationsrw_page-support-thp drivers/nvdimm/pmem.c
--- a/drivers/nvdimm/pmem.c~block-thp-make-block_device_operationsrw_page-support-thp
+++ a/drivers/nvdimm/pmem.c
@@ -80,22 +80,40 @@ static blk_status_t pmem_clear_poison(st
 static void write_pmem(void *pmem_addr, struct page *page,
 		unsigned int off, unsigned int len)
 {
-	void *mem = kmap_atomic(page);
+	unsigned int chunk;
+	void *mem;
 
-	memcpy_flushcache(pmem_addr, mem + off, len);
-	kunmap_atomic(mem);
+	while (len) {
+		mem = kmap_atomic(page);
+		chunk = min_t(unsigned int, len, PAGE_SIZE);
+		memcpy_flushcache(pmem_addr, mem + off, chunk);
+		kunmap_atomic(mem);
+		len -= chunk;
+		off = 0;
+		page++;
+		pmem_addr += PAGE_SIZE;
+	}
 }
 
 static blk_status_t read_pmem(struct page *page, unsigned int off,
 		void *pmem_addr, unsigned int len)
 {
+	unsigned int chunk;
 	int rc;
-	void *mem = kmap_atomic(page);
+	void *mem;
 
-	rc = memcpy_mcsafe(mem + off, pmem_addr, len);
-	kunmap_atomic(mem);
-	if (rc)
-		return BLK_STS_IOERR;
+	while (len) {
+		mem = kmap_atomic(page);
+		chunk = min_t(unsigned int, len, PAGE_SIZE);
+		rc = memcpy_mcsafe(mem + off, pmem_addr, chunk);
+		kunmap_atomic(mem);
+		if (rc)
+			return BLK_STS_IOERR;
+		len -= chunk;
+		off = 0;
+		page++;
+		pmem_addr += PAGE_SIZE;
+	}
 	return BLK_STS_OK;
 }
 
@@ -188,7 +206,8 @@ static int pmem_rw_page(struct block_dev
 	struct pmem_device *pmem = bdev->bd_queue->queuedata;
 	blk_status_t rc;
 
-	rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, is_write, sector);
+	rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE,
+			  0, is_write, sector);
 
 	/*
 	 * The ->rw_page interface is subtle and tricky.  The core
_
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux