summaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2019-11-25 10:59:41 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-11-25 10:59:41 -0800
commitff6814b078e33a4d26fee9ea80779c81a6744cd8 (patch)
treeb8559e89e01cad7d59e41e485d5c20ac6bb2e7ec /Documentation
parent6e7b06a4c88846c20c2cc01b370564a2423ff0d0 (diff)
parent1e279153dfd53e76006720df804d5935a6cbc6d5 (diff)
downloadlinux-ff6814b078e33a4d26fee9ea80779c81a6744cd8.tar.bz2
Merge tag 'for-5.5/block-20191121' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe: "Due to more granular branches, this one is small and will be followed with other core branches that add specific features. I meant to just have a core and drivers branch, but external dependencies we ended up adding a few more that are also core. The changes are: - Fixes and improvements for the zoned device support (Ajay, Damien) - sed-opal table writing and datastore UID (Revanth) - blk-cgroup (and bfq) blk-cgroup stat fixes (Tejun) - Improvements to the block stats tracking (Pavel) - Fix for overruning sysfs buffer for large number of CPUs (Ming) - Optimization for small IO (Ming, Christoph) - Fix typo in RWH lifetime hint (Eugene) - Dead code removal and documentation (Bart) - Reduction in memory usage for queue and tag set (Bart) - Kerneldoc header documentation (André) - Device/partition revalidation fixes (Jan) - Stats tracking for flush requests (Konstantin) - Various other little fixes here and there (et al)" * tag 'for-5.5/block-20191121' of git://git.kernel.dk/linux-block: (48 commits) Revert "block: split bio if the only bvec's length is > SZ_4K" block: add iostat counters for flush requests block,bfq: Skip tracing hooks if possible block: sed-opal: Introduce SUM_SET_LIST parameter and append it using 'add_token_u64' blk-cgroup: cgroup_rstat_updated() shouldn't be called on cgroup1 block: Don't disable interrupts in trigger_softirq() sbitmap: Delete sbitmap_any_bit_clear() blk-mq: Delete blk_mq_has_free_tags() and blk_mq_can_queue() block: split bio if the only bvec's length is > SZ_4K block: still try to split bio if the bvec crosses pages blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT blk-cgroup: reimplement basic IO stats using cgroup rstat blk-cgroup: remove now unused blkg_print_stat_{bytes|ios}_recursive() blk-throtl: stop using blkg->stat_bytes and ->stat_ios bfq-iosched: stop using blkg->stat_bytes and ->stat_ios bfq-iosched: relocate bfqg_*rwstat*() helpers block: add zone open, close and finish ioctl support block: add zone open, close and finish operations block: Simplify REQ_OP_ZONE_RESET_ALL handling block: Remove REQ_OP_ZONE_RESET plugging ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/procfs-diskstats5
-rw-r--r--Documentation/ABI/testing/sysfs-block6
-rw-r--r--Documentation/admin-guide/iostats.rst9
-rw-r--r--Documentation/block/stat.rst14
4 files changed, 32 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/procfs-diskstats b/Documentation/ABI/testing/procfs-diskstats
index 2c44b4f1b060..70dcaf2481f4 100644
--- a/Documentation/ABI/testing/procfs-diskstats
+++ b/Documentation/ABI/testing/procfs-diskstats
@@ -29,4 +29,9 @@ Description:
17 - sectors discarded
18 - time spent discarding
+ Kernel 5.5+ appends two more fields for flush requests:
+
+ 19 - flush requests completed successfully
+ 20 - time spent flushing
+
For more details refer to Documentation/admin-guide/iostats.rst
diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
index f8c7c7126bb1..ed8c14f161ee 100644
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@@ -15,6 +15,12 @@ Description:
9 - I/Os currently in progress
10 - time spent doing I/Os (ms)
11 - weighted time spent doing I/Os (ms)
+ 12 - discards completed
+ 13 - discards merged
+ 14 - sectors discarded
+ 15 - time spent discarding (ms)
+ 16 - flush requests completed
+ 17 - time spent flushing (ms)
For more details refer Documentation/admin-guide/iostats.rst
diff --git a/Documentation/admin-guide/iostats.rst b/Documentation/admin-guide/iostats.rst
index 5d63b18bd6d1..4f0462af3ca7 100644
--- a/Documentation/admin-guide/iostats.rst
+++ b/Documentation/admin-guide/iostats.rst
@@ -121,6 +121,15 @@ Field 15 -- # of milliseconds spent discarding
This is the total number of milliseconds spent by all discards (as
measured from __make_request() to end_that_request_last()).
+Field 16 -- # of flush requests completed
+ This is the total number of flush requests completed successfully.
+
+ Block layer combines flush requests and executes at most one at a time.
+ This counts flush requests executed by disk. Not tracked for partitions.
+
+Field 17 -- # of milliseconds spent flushing
+ This is the total number of milliseconds spent by all flush requests.
+
To avoid introducing performance bottlenecks, no locks are held while
modifying these counters. This implies that minor inaccuracies may be
introduced when changes collide, so (for instance) adding up all the
diff --git a/Documentation/block/stat.rst b/Documentation/block/stat.rst
index 9c07bc22b0bc..77311335c08b 100644
--- a/Documentation/block/stat.rst
+++ b/Documentation/block/stat.rst
@@ -41,6 +41,8 @@ discard I/Os requests number of discard I/Os processed
discard merges requests number of discard I/Os merged with in-queue I/O
discard sectors sectors number of sectors discarded
discard ticks milliseconds total wait time for discard requests
+flush I/Os requests number of flush I/Os processed
+flush ticks milliseconds total wait time for flush requests
=============== ============= =================================================
read I/Os, write I/Os, discard I/0s
@@ -48,6 +50,14 @@ read I/Os, write I/Os, discard I/0s
These values increment when an I/O request completes.
+flush I/Os
+==========
+
+These values increment when an flush I/O request completes.
+
+Block layer combines flush requests and executes at most one at a time.
+This counts flush requests executed by disk. Not tracked for partitions.
+
read merges, write merges, discard merges
=========================================
@@ -62,8 +72,8 @@ discarded from this block device. The "sectors" in question are the
standard UNIX 512-byte sectors, not any device- or filesystem-specific
block size. The counters are incremented when the I/O completes.
-read ticks, write ticks, discard ticks
-======================================
+read ticks, write ticks, discard ticks, flush ticks
+===================================================
These values count the number of milliseconds that I/O requests have
waited on this block device. If there are multiple I/O requests waiting,