blk-cgroup: Lower minimum weight from 100 to 10.
Subsystems (2)
PATCH 1/1 blk-cgroup: Lower minimum weight from 100 to 10.
We've found that we still get good, useful isolation at weights this low. I'd like to adjust the minimum so that any other changes can take these values into account.
--- Documentation/cgroups/blkio-controller.txt | 2 +- block/blk-cgroup.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
Documentation/cgroups/blkio-controller.txt +1 -1
@@ -140,7 +140,7 @@ Proportional weight policy files - Specifies per cgroup weight. This is default weight of the group on all the devices until and unless overridden by per device rule. (See blkio.weight_device). - Currently allowed range of weights is from 100 to 1000. + Currently allowed range of weights is from 10 to 1000. - blkio.weight_device - One can specify per cgroup per device rules using this interface.
block/blk-cgroup.h +1 -1
@@ -240,7 +240,7 @@ static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }#endif -#define BLKIO_WEIGHT_MIN 100 +#define BLKIO_WEIGHT_MIN 10#define BLKIO_WEIGHT_MAX 1000#define BLKIO_WEIGHT_DEFAULT 500
Signature · 1 line
1.7.3.1
Quoted 8 lines · Justin TerAvest
We've found that we still get good, useful isolation at weights this low. I'd like to adjust the minimum so that any other changes can take these values into account.
--- Documentation/cgroups/blkio-controller.txt | 2 +- block/blk-cgroup.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
Looks good to me.
Thanks
Vivek
Quoted 28 lines
Documentation/cgroups/blkio-controller.txt +1
-1@@ -140,7 +140,7 @@ Proportional weight policy files - Specifies per cgroup weight. This is default weight of the group on all the devices until and unless overridden by per device rule. (See blkio.weight_device). - Currently allowed range of weights is from 100 to 1000. + Currently allowed range of weights is from 10 to 1000. - blkio.weight_device - One can specify per cgroup per device rules using this interface.block/blk-cgroup.h +1
-1@@ -240,7 +240,7 @@ static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }#endif -#define BLKIO_WEIGHT_MIN 100 +#define BLKIO_WEIGHT_MIN 10#define BLKIO_WEIGHT_MAX 1000#define BLKIO_WEIGHT_DEFAULT 500Signature · 1 line
1.7.3.1
Quoted 3 lines · Justin TerAvest
We've found that we still get good, useful isolation at weights this low. I'd like to adjust the minimum so that any other changes can take these values into account.
Justin, this looks fine to me if Vivek agrees. You did not sign-off on the patch though, so I can't apply it yet. Please re-send with the ack from Vivek added and your signed-off-by as well.
Signature · 1 line
Jens Axboe
Quoted 8 lines · Jens Axboe
Quoted 3 lines · Justin TerAvest
We've found that we still get good, useful isolation at weights this low. I'd like to adjust the minimum so that any other changes can take these values into account.
Justin, this looks fine to me if Vivek agrees. You did not sign-off on the patch though, so I can't apply it yet. Please re-send with the ack from Vivek added and your signed-off-by as well.
The primary reason I am fine with wider weight range because there are many situations where we just don't get effective 10 times service differentiation for various reasons like workload don't seem to be active at the service tree at the same time or if we decide to swith off idling on faster storage etc.
So because of this leaky nature of service differentiation, it might help to have a wider range of allowed weights.
Thanks
Vivek