[PATCHSET] blkcg: update locking and fix stacking

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


Hey, guys.

This is the third patchset of blkcg API cleanup series and does the
following two things.

* Drops RCU and use double locking.  As with ioc, we might want to
  re-introduce RCU in more restricted form to walk blkg from blkcg but
  for now there's no need.  cgroup deletion is much colder than task
  exit and there's no other path which requires reverse double
  locking.

* Before this patchset, blk-throttle and cfq-iosched propio couldn't
  be used together because for any bios delayed by blk-throttle would
  be issued by a worker thread and get dumped to the default cgroup.
  So, bios will be nondeterministically thrown into the root cg.  This
  isn't a problem limited to blk-throttle.  Any mechanism which punts
  bios to a different task (e.g. btrfs) would mess up IO scheduling
  for both cgroups and iocontexts.

  This patchset implements a mechanism to associate a bio to a task
  (its cgroup and ioc actually) and block layer will handle the
  request as if it were issued by the associated task no matter which
  task actually ends up issuing it to block layer.  It's applied to
  blk-throttle such that any delayed bio is associated to the original
  task.

This patchset contains the following 9 patches.

 0001-blkcg-use-double-locking-instead-of-RCU-for-blkg-syn.patch
 0002-blkcg-drop-unnecessary-RCU-locking.patch
 0003-block-restructure-get_request.patch
 0004-block-interface-update-for-ioc-icq-creation-function.patch
 0005-block-ioc_task_link-can-t-fail.patch
 0006-block-add-io_context-active_ref.patch
 0007-block-implement-bio_associate_current.patch
 0008-block-make-block-cgroup-policies-follow-bio-task-ass.patch
 0009-block-make-blk-throttle-preserve-the-issuing-task-on.patch

 0001-0002 updates locking and strips out RCU.

 0003-0006 prepare for bio task association.

 0007-0009 implement bio task association and apply it to
 blk-throttle.

This patchset is on top of

  block/for-linus 621032ad6eaabf2fe771c4fa0d8f58e1fcfcdba6
+ [1] blkcg: kill policy node and blkg->dev, take#4
+ [2] blkcg: unify blkgs for different policies (updated)

and is also available in the following git branch.

 git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git blkcg-locking

The git branch has separate branches for previous patchsets, so using
it probably is the easiest way to review this series.  Jens, if you
want the whole thing reposted, please let me know.

diffstat follows.

 block/blk-cgroup.c        |  167 +++++++++++++++++-----------------------------
 block/blk-cgroup.h        |   12 +--
 block/blk-core.c          |   92 ++++++++++++++-----------
 block/blk-ioc.c           |   58 +++++++++------
 block/blk-throttle.c      |   41 +----------
 block/blk.h               |   24 +++---
 block/cfq-iosched.c       |   54 ++++----------
 block/cfq.h               |   10 --
 block/elevator.c          |    5 -
 fs/bio.c                  |   61 ++++++++++++++++
 include/linux/bio.h       |    8 ++
 include/linux/blk_types.h |   10 ++
 include/linux/blkdev.h    |    1 
 include/linux/elevator.h  |    6 +
 include/linux/iocontext.h |   32 ++++++--
 kernel/fork.c             |    5 -
 16 files changed, 299 insertions(+), 287 deletions(-)

Thanks.

--
tejun

[1] http://thread.gmane.org/gmane.linux.kernel/1247152
[2] http://thread.gmane.org/gmane.linux.kernel/1247287
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


[Other Archives]     [Linux Kernel Newbies]     [Linux Driver Development]     [Fedora Kernel]     [Linux Kernel Testers]     [Linux SH]     [Linux Omap]     [Linux Kbuild]     [Linux Tape]     [Linux Input]     [Linux Kernel Janitors]     [Linux Kernel Packagers]     [Linux Doc]     [Linux Man Pages]     [Linux API]     [Linux Memory Management]     [Linux Modules]     [Linux Standards]     [Kernel Announce]     [Netdev]     [Git]     [Linux PCI]     Linux CAN Development     [Linux I2C]     [Linux RDMA]     [Linux NUMA]     [Netfilter]     [Netfilter Devel]     [SELinux]     [Bugtraq]     [FIO]     [Linux Perf Users]     [Linux Serial]     [Linux PPP]     [Linux ISDN]     [Linux Next]     [Kernel Stable Commits]     [Linux Tip Commits]     [Kernel MM Commits]     [Linux Security Module]     [Filesystem Development]     [Ext3 Filesystem]     [Linux bcache]     [Ext4 Filesystem]     [Linux BTRFS]     [Linux CEPH Filesystem]     [Linux XFS]     [XFS]     [Linux NFS]     [Linux CIFS]     [Ecryptfs]     [Linux NILFS]     [Linux Cachefs]     [Reiser FS]     [Initramfs]     [Linux FB Devel]     [Linux OpenGL]     [DRI Devel]     [Fastboot]     [Linux RT Users]     [Linux RT Stable]     [eCos]     [Corosync]     [Linux Clusters]     [LVS Devel]     [Hot Plug]     [Linux Virtualization]     [KVM]     [KVM PPC]     [KVM ia64]     [Linux Containers]     [Linux Hexagon]     [Linux Cgroups]     [Util Linux]     [Wireless]     [Linux Bluetooth]     [Bluez Devel]     [Ethernet Bridging]     [Embedded Linux]     [Barebox]     [Linux MMC]     [Linux IIO]     [Sparse]     [Smatch]     [Linux Arch]     [x86 Platform Driver]     [Linux ACPI]     [Linux IBM ACPI]     [LM Sensors]     [CPU Freq]     [Linux Power Management]     [Linmodems]     [Linux DCCP]     [Linux SCTP]     [ALSA Devel]     [Linux USB]     [Linux PA RISC]     [Linux Samsung SOC]     [MIPS Linux]     [IBM S/390 Linux]     [ARM Linux]     [ARM Kernel]     [ARM MSM]     [Tegra Devel]     [Sparc Linux]     [Linux Security]     [Linux Sound]     [Linux Media]     [Video 4 Linux]     [Linux IRDA Users]     [Linux for the blind]     [Linux RAID]     [Linux ATA RAID]     [Device Mapper]     [Linux SCSI]     [SCSI Target Devel]     [Linux SCSI Target Infrastructure]     [Linux IDE]     [Linux SMP]     [Linux AXP]     [Linux Alpha]     [Linux M68K]     [Linux ia64]     [Linux 8086]     [Linux x86_64]     [Linux Config]     [Linux Apps]     [Linux MSDOS]     [Linux X.25]     [Linux Crypto]     [DM Crypt]     [Linux Trace Users]     [Linux Btrace]     [Linux Watchdog]     [Utrace Devel]     [Linux C Programming]     [Linux Assembly]     [Dash]     [DWARVES]     [Hail Devel]     [Linux Kernel Debugger]     [Linux gcc]     [Gcc Help]     [X.Org]     [Wine]

Add to Google Powered by Linux

[Older Kernel Discussion]     [Yosemite National Park Forum]     [Large Format Photos]     [Gimp]     [Yosemite Photos]     [Stuff]