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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-09 19:45:06 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-09 19:45:06 +0200
commit3b99107f0e0298e6fe0787f75b8f3d8306dfb230 (patch)
tree30536dbc9ca176470a2ae2938f952381e33f5deb /Documentation/block
parentMerge tag 'devprop-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/... (diff)
parentblk-iolatency: fix STS_AGAIN handling (diff)
downloadlinux-3b99107f0e0298e6fe0787f75b8f3d8306dfb230.tar.xz
linux-3b99107f0e0298e6fe0787f75b8f3d8306dfb230.zip
Merge tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe: "This is the main block updates for 5.3. Nothing earth shattering or major in here, just fixes, additions, and improvements all over the map. This contains: - Series of documentation fixes (Bart) - Optimization of the blk-mq ctx get/put (Bart) - null_blk removal race condition fix (Bob) - req/bio_op() cleanups (Chaitanya) - Series cleaning up the segment accounting, and request/bio mapping (Christoph) - Series cleaning up the page getting/putting for bios (Christoph) - block cgroup cleanups and moving it to where it is used (Christoph) - block cgroup fixes (Tejun) - Series of fixes and improvements to bcache, most notably a write deadlock fix (Coly) - blk-iolatency STS_AGAIN and accounting fixes (Dennis) - Series of improvements and fixes to BFQ (Douglas, Paolo) - debugfs_create() return value check removal for drbd (Greg) - Use struct_size(), where appropriate (Gustavo) - Two lighnvm fixes (Heiner, Geert) - MD fixes, including a read balance and corruption fix (Guoqing, Marcos, Xiao, Yufen) - block opal shadow mbr additions (Jonas, Revanth) - sbitmap compare-and-exhange improvemnts (Pavel) - Fix for potential bio->bi_size overflow (Ming) - NVMe pull requests: - improved PCIe suspent support (Keith Busch) - error injection support for the admin queue (Akinobu Mita) - Fibre Channel discovery improvements (James Smart) - tracing improvements including nvmetc tracing support (Minwoo Im) - misc fixes and cleanups (Anton Eidelman, Minwoo Im, Chaitanya Kulkarni)" - Various little fixes and improvements to drivers and core" * tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-block: (153 commits) blk-iolatency: fix STS_AGAIN handling block: nr_phys_segments needs to be zero for REQ_OP_WRITE_ZEROES blk-mq: simplify blk_mq_make_request() blk-mq: remove blk_mq_put_ctx() sbitmap: Replace cmpxchg with xchg block: fix .bi_size overflow block: sed-opal: check size of shadow mbr block: sed-opal: ioctl for writing to shadow mbr block: sed-opal: add ioctl for done-mark of shadow mbr block: never take page references for ITER_BVEC direct-io: use bio_release_pages in dio_bio_complete block_dev: use bio_release_pages in bio_unmap_user block_dev: use bio_release_pages in blkdev_bio_end_io iomap: use bio_release_pages in iomap_dio_bio_end_io block: use bio_release_pages in bio_map_user_iov block: use bio_release_pages in bio_unmap_user block: optionally mark pages dirty in bio_release_pages block: move the BIO_NO_PAGE_REF check into bio_release_pages block: skd_main.c: Remove call to memset after dma_alloc_coherent block: mtip32xx: Remove call to memset after dma_alloc_coherent ...
Diffstat (limited to 'Documentation/block')
-rw-r--r--Documentation/block/bfq-iosched.txt12
-rw-r--r--Documentation/block/biodoc.txt1
-rw-r--r--Documentation/block/queue-sysfs.txt64
3 files changed, 49 insertions, 28 deletions
diff --git a/Documentation/block/bfq-iosched.txt b/Documentation/block/bfq-iosched.txt
index b2265cf6c9c3..bbd6eb5bbb07 100644
--- a/Documentation/block/bfq-iosched.txt
+++ b/Documentation/block/bfq-iosched.txt
@@ -38,13 +38,13 @@ stack). To give an idea of the limits with BFQ, on slow or average
CPUs, here are, first, the limits of BFQ for three different CPUs, on,
respectively, an average laptop, an old desktop, and a cheap embedded
system, in case full hierarchical support is enabled (i.e.,
-CONFIG_BFQ_GROUP_IOSCHED is set), but CONFIG_DEBUG_BLK_CGROUP is not
+CONFIG_BFQ_GROUP_IOSCHED is set), but CONFIG_BFQ_CGROUP_DEBUG is not
set (Section 4-2):
- Intel i7-4850HQ: 400 KIOPS
- AMD A8-3850: 250 KIOPS
- ARM CortexTM-A53 Octa-core: 80 KIOPS
-If CONFIG_DEBUG_BLK_CGROUP is set (and of course full hierarchical
+If CONFIG_BFQ_CGROUP_DEBUG is set (and of course full hierarchical
support is enabled), then the sustainable throughput with BFQ
decreases, because all blkio.bfq* statistics are created and updated
(Section 4-2). For BFQ, this leads to the following maximum
@@ -537,19 +537,19 @@ or io.bfq.weight.
As for cgroups-v1 (blkio controller), the exact set of stat files
created, and kept up-to-date by bfq, depends on whether
-CONFIG_DEBUG_BLK_CGROUP is set. If it is set, then bfq creates all
+CONFIG_BFQ_CGROUP_DEBUG is set. If it is set, then bfq creates all
the stat files documented in
Documentation/cgroup-v1/blkio-controller.rst. If, instead,
-CONFIG_DEBUG_BLK_CGROUP is not set, then bfq creates only the files
+CONFIG_BFQ_CGROUP_DEBUG is not set, then bfq creates only the files
blkio.bfq.io_service_bytes
blkio.bfq.io_service_bytes_recursive
blkio.bfq.io_serviced
blkio.bfq.io_serviced_recursive
-The value of CONFIG_DEBUG_BLK_CGROUP greatly influences the maximum
+The value of CONFIG_BFQ_CGROUP_DEBUG greatly influences the maximum
throughput sustainable with bfq, because updating the blkio.bfq.*
stats is rather costly, especially for some of the stats enabled by
-CONFIG_DEBUG_BLK_CGROUP.
+CONFIG_BFQ_CGROUP_DEBUG.
Parameters to set
-----------------
diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt
index ac18b488cb5e..31c177663ed5 100644
--- a/Documentation/block/biodoc.txt
+++ b/Documentation/block/biodoc.txt
@@ -436,7 +436,6 @@ struct bio {
struct bvec_iter bi_iter; /* current index into bio_vec array */
unsigned int bi_size; /* total size in bytes */
- unsigned short bi_phys_segments; /* segments after physaddr coalesce*/
unsigned short bi_hw_segments; /* segments after DMA remapping */
unsigned int bi_max; /* max bio_vecs we can hold
used as index into pool */
diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt
index 83b457e24bba..b40b5b7cebd9 100644
--- a/Documentation/block/queue-sysfs.txt
+++ b/Documentation/block/queue-sysfs.txt
@@ -14,6 +14,15 @@ add_random (RW)
This file allows to turn off the disk entropy contribution. Default
value of this file is '1'(on).
+chunk_sectors (RO)
+------------------
+This has different meaning depending on the type of the block device.
+For a RAID device (dm-raid), chunk_sectors indicates the size in 512B sectors
+of the RAID volume stripe segment. For a zoned block device, either host-aware
+or host-managed, chunk_sectors indicates the size in 512B sectors of the zones
+of the device, with the eventual exception of the last zone of the device which
+may be smaller.
+
dax (RO)
--------
This file indicates whether the device supports Direct Access (DAX),
@@ -43,6 +52,16 @@ large discards are issued, setting this value lower will make Linux issue
smaller discards and potentially help reduce latencies induced by large
discard operations.
+discard_zeroes_data (RO)
+------------------------
+Obsolete. Always zero.
+
+fua (RO)
+--------
+Whether or not the block driver supports the FUA flag for write requests.
+FUA stands for Force Unit Access. If the FUA flag is set that means that
+write requests must bypass the volatile cache of the storage device.
+
hw_sector_size (RO)
-------------------
This is the hardware sector size of the device, in bytes.
@@ -83,14 +102,19 @@ logical_block_size (RO)
-----------------------
This is the logical block size of the device, in bytes.
+max_discard_segments (RO)
+-------------------------
+The maximum number of DMA scatter/gather entries in a discard request.
+
max_hw_sectors_kb (RO)
----------------------
This is the maximum number of kilobytes supported in a single data transfer.
max_integrity_segments (RO)
---------------------------
-When read, this file shows the max limit of integrity segments as
-set by block layer which a hardware controller can handle.
+Maximum number of elements in a DMA scatter/gather list with integrity
+data that will be submitted by the block layer core to the associated
+block driver.
max_sectors_kb (RW)
-------------------
@@ -100,11 +124,12 @@ size allowed by the hardware.
max_segments (RO)
-----------------
-Maximum number of segments of the device.
+Maximum number of elements in a DMA scatter/gather list that is submitted
+to the associated block driver.
max_segment_size (RO)
---------------------
-Maximum segment size of the device.
+Maximum size in bytes of a single element in a DMA scatter/gather list.
minimum_io_size (RO)
--------------------
@@ -132,6 +157,12 @@ per-block-cgroup request pool. IOW, if there are N block cgroups,
each request queue may have up to N request pools, each independently
regulated by nr_requests.
+nr_zones (RO)
+-------------
+For zoned block devices (zoned attribute indicating "host-managed" or
+"host-aware"), this indicates the total number of zones of the device.
+This is always 0 for regular block devices.
+
optimal_io_size (RO)
--------------------
This is the optimal IO size reported by the device.
@@ -185,8 +216,8 @@ This is the number of bytes the device can write in a single write-same
command. A value of '0' means write-same is not supported by this
device.
-wb_lat_usec (RW)
-----------------
+wbt_lat_usec (RW)
+-----------------
If the device is registered for writeback throttling, then this file shows
the target minimum read latency. If this latency is exceeded in a given
window of time (see wb_window_usec), then the writeback throttling will start
@@ -201,6 +232,12 @@ blk-throttle makes decision based on the samplings. Lower time means cgroups
have more smooth throughput, but higher CPU overhead. This exists only when
CONFIG_BLK_DEV_THROTTLING_LOW is enabled.
+write_zeroes_max_bytes (RO)
+---------------------------
+For block drivers that support REQ_OP_WRITE_ZEROES, the maximum number of
+bytes that can be zeroed at once. The value 0 means that REQ_OP_WRITE_ZEROES
+is not supported.
+
zoned (RO)
----------
This indicates if the device is a zoned block device and the zone model of the
@@ -213,19 +250,4 @@ devices are described in the ZBC (Zoned Block Commands) and ZAC
do not support zone commands, they will be treated as regular block devices
and zoned will report "none".
-nr_zones (RO)
--------------
-For zoned block devices (zoned attribute indicating "host-managed" or
-"host-aware"), this indicates the total number of zones of the device.
-This is always 0 for regular block devices.
-
-chunk_sectors (RO)
-------------------
-This has different meaning depending on the type of the block device.
-For a RAID device (dm-raid), chunk_sectors indicates the size in 512B sectors
-of the RAID volume stripe segment. For a zoned block device, either host-aware
-or host-managed, chunk_sectors indicates the size in 512B sectors of the zones
-of the device, with the eventual exception of the last zone of the device which
-may be smaller.
-
Jens Axboe <jens.axboe@oracle.com>, February 2009