Messages in this thread | | | Date | Wed, 2 Dec 2009 10:27:22 -0500 | From | Vivek Goyal <> | Subject | Re: [PATCH 06/21] blkio: Introduce blkio controller cgroup interface |
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On Tue, Dec 01, 2009 at 05:34:37AM +0530, Divyesh Shah wrote: > On Mon, Nov 30, 2009 at 8:29 AM, Vivek Goyal <vgoyal@redhat.com> wrote: > > o This is basic implementation of blkio controller cgroup interface. This is > > the common interface visible to user space and should be used by different > > IO control policies as we implement those. > > > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > > --- > > block/Kconfig | 13 +++ > > block/Kconfig.iosched | 1 + > > block/Makefile | 1 + > > block/blk-cgroup.c | 177 +++++++++++++++++++++++++++++++++++++++++ > > block/blk-cgroup.h | 58 +++++++++++++ > > include/linux/cgroup_subsys.h | 6 ++ > > include/linux/iocontext.h | 4 + > > 7 files changed, 260 insertions(+), 0 deletions(-) > > create mode 100644 block/blk-cgroup.c > > create mode 100644 block/blk-cgroup.h > > > > diff --git a/block/Kconfig b/block/Kconfig > > index 9be0b56..6ba1a8e 100644 > > --- a/block/Kconfig > > +++ b/block/Kconfig > > @@ -77,6 +77,19 @@ config BLK_DEV_INTEGRITY > > T10/SCSI Data Integrity Field or the T13/ATA External Path > > Protection. If in doubt, say N. > > > > +config BLK_CGROUP > > + bool > > + depends on CGROUPS > > + default n > > + ---help--- > > + Generic block IO controller cgroup interface. This is the common > > + cgroup interface which should be used by various IO controlling > > + policies. > > + > > + Currently, CFQ IO scheduler uses it to recognize task groups and > > + control disk bandwidth allocation (proportional time slice allocation) > > + to such task groups. > > + > > endif # BLOCK > > > > config BLOCK_COMPAT > > diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched > > index 8bd1051..be0280d 100644 > > --- a/block/Kconfig.iosched > > +++ b/block/Kconfig.iosched > > @@ -23,6 +23,7 @@ config IOSCHED_DEADLINE > > > > config IOSCHED_CFQ > > tristate "CFQ I/O scheduler" > > + select BLK_CGROUP > > default y > > ---help--- > > The CFQ I/O scheduler tries to distribute bandwidth equally > > diff --git a/block/Makefile b/block/Makefile > > index 7914108..cb2d515 100644 > > --- a/block/Makefile > > +++ b/block/Makefile > > @@ -8,6 +8,7 @@ obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \ > > blk-iopoll.o ioctl.o genhd.o scsi_ioctl.o > > > > obj-$(CONFIG_BLK_DEV_BSG) += bsg.o > > +obj-$(CONFIG_BLK_CGROUP) += blk-cgroup.o > > obj-$(CONFIG_IOSCHED_NOOP) += noop-iosched.o > > obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o > > obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o > > diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c > > new file mode 100644 > > index 0000000..4f6afd7 > > --- /dev/null > > +++ b/block/blk-cgroup.c > > @@ -0,0 +1,177 @@ > > +/* > > + * Common Block IO controller cgroup interface > > + * > > + * Based on ideas and code from CFQ, CFS and BFQ: > > + * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> > > + * > > + * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it> > > + * Paolo Valente <paolo.valente@unimore.it> > > + * > > + * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com> > > + * Nauman Rafique <nauman@google.com> > > + */ > > +#include <linux/ioprio.h> > > +#include "blk-cgroup.h" > > + > > +struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT }; > > This should use BLKIO_WEIGHT_MAX as 2*BLKIO_WEIGHT_DEFAULT is same as > BLKIO_WEIGHT_MAX unless there is a reason why you would want the value > to remain as a multiple of default_weight instead of max in case the > constants change later. >
Hi Divyesh,
Every new group gets the weight as BLKIO_WEIGHT_DEFAULT. For root group by default I wanted to give it double the weight to begin with as it will have all the async queues, will also have all the sync-noidle queues (in case of group_isolation=0) and will be doing all the system IO.
That's a different thing that 2*BLKIO_WEIGHT_DEFAULT happens to be same as BLKIO_WEIGHT_MAX.
So functionality wise it does not change anything. It is just a matter of what is more intutive as a root group default.
To me 2*BLKIO_WEIGHT_DEFAULT looks just fine. So I will keep it as it is, unless you really think that it is not intutive and BLKIO_WEIGHT_MAX is more intutive.
Thanks Vivek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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