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authorChristoph Hellwig <hch@lst.de>2019-06-06 12:26:24 +0200
committerJens Axboe <axboe@kernel.dk>2019-06-20 10:32:35 -0600
commit8060c47ba853f147c46bf1e6f6d93d1726fcb57a (patch)
treeccab63ea63d2b21044874e93f2e0595c62774ade /Documentation
parentd6258980daf207f986676e59e6ea295204cdc84e (diff)
block: rename CONFIG_DEBUG_BLK_CGROUP to CONFIG_BFQ_CGROUP_DEBUG
This option is entirely bfq specific, give it an appropinquate name. Also make it depend on CONFIG_BFQ_GROUP_IOSCHED in Kconfig, as all the functionality already does so anyway. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/block/bfq-iosched.txt12
-rw-r--r--Documentation/cgroup-v1/blkio-controller.txt12
2 files changed, 12 insertions, 12 deletions
diff --git a/Documentation/block/bfq-iosched.txt b/Documentation/block/bfq-iosched.txt
index 1a0f2ac02eb6..f02163fabf80 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.txt. 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/cgroup-v1/blkio-controller.txt b/Documentation/cgroup-v1/blkio-controller.txt
index d1a1b7bdd03a..78ec4500f220 100644
--- a/Documentation/cgroup-v1/blkio-controller.txt
+++ b/Documentation/cgroup-v1/blkio-controller.txt
@@ -77,7 +77,7 @@ Various user visible config options
CONFIG_BLK_CGROUP
- Block IO controller.
-CONFIG_DEBUG_BLK_CGROUP
+CONFIG_BFQ_CGROUP_DEBUG
- Debug help. Right now some additional stats file show up in cgroup
if this option is enabled.
@@ -193,13 +193,13 @@ Proportional weight policy files
write, sync or async.
- blkio.avg_queue_size
- - Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
+ - Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
The average queue size for this cgroup over the entire time of this
cgroup's existence. Queue size samples are taken each time one of the
queues of this cgroup gets a timeslice.
- blkio.group_wait_time
- - Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
+ - Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
This is the amount of time the cgroup had to wait since it became busy
(i.e., went from 0 to 1 request queued) to get a timeslice for one of
its queues. This is different from the io_wait_time which is the
@@ -210,7 +210,7 @@ Proportional weight policy files
got a timeslice and will not include the current delta.
- blkio.empty_time
- - Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
+ - Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
This is the amount of time a cgroup spends without any pending
requests when not being served, i.e., it does not include any time
spent idling for one of the queues of the cgroup. This is in
@@ -219,7 +219,7 @@ Proportional weight policy files
time it had a pending request and will not include the current delta.
- blkio.idle_time
- - Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y.
+ - Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y.
This is the amount of time spent by the IO scheduler idling for a
given cgroup in anticipation of a better request than the existing ones
from other queues/cgroups. This is in nanoseconds. If this is read
@@ -228,7 +228,7 @@ Proportional weight policy files
the current delta.
- blkio.dequeue
- - Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y. This
+ - Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y. This
gives the statistics about how many a times a group was dequeued
from service tree of the device. First two fields specify the major
and minor number of the device and third field specifies the number