mbox series

[ndctl,v3,0/3] Replace udev rule for latch and dirty-shutdown-count

Message ID 153809529764.1963951.7530312689559729607.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive)
Headers show
Series Replace udev rule for latch and dirty-shutdown-count | expand

Message

Dan Williams Sept. 28, 2018, 12:41 a.m. UTC
Changes since v2 [1]:
* Drop the 'dirty-dimm' command
* Add ndctl_dimm_get_dirty_shutdown() api

[1]: https://lists.01.org/pipermail/linux-nvdimm/2018-September/017890.html

---

The latch mechanism is awkward especially when all that it needed is a
rolling count of dirty-shutdown events. The expectation going forward is
that the platform firmware will handle the latch, if it is present, and
the OS need only consume the dirty-shutdown count. The ndctl
implementation called libndctl apis from the udev queue which we
discovered injects unnecessary udev queue drains / stalls into the boot
path. Lastly, the userspace caching scheme for non-root users to consume
the dirty-shutdown-count just isn't as efficient as teaching the kernel
to cache this value and export it as a standard sysfs attribute.

---

Dan Williams (3):
      ndctl, lib: Add dirty-shutdown-count retrieval helper
      ndctl: Revert "ndctl, intel: Fallback to smart cached shutdown_count"
      ndctl: Revert "ndctl: Create ndctl udev rules for dirty shutdown"


 .gitignore             |    1 
 Makefile.am            |    3 -
 configure.ac           |   10 ---
 contrib/80-ndctl.rules |    3 -
 ndctl.spec.in          |    3 -
 ndctl/Makefile.am      |    5 --
 ndctl/lib/intel.c      |   41 -------------
 ndctl/lib/libndctl.c   |   16 ++++-
 ndctl/lib/libndctl.sym |    5 ++
 ndctl/lib/private.h    |    4 -
 ndctl/libndctl.h       |    1 
 ndctl/ndctl-udev.c     |  150 ------------------------------------------------
 test/libndctl.c        |   29 +++++++--
 13 files changed, 40 insertions(+), 231 deletions(-)
 delete mode 100644 contrib/80-ndctl.rules
 delete mode 100644 ndctl/ndctl-udev.c

Comments

Vishal Verma Oct. 3, 2018, 1:08 a.m. UTC | #1
On Thu, 2018-09-27 at 17:41 -0700, Dan Williams wrote:
> Changes since v2 [1]:
> * Drop the 'dirty-dimm' command
> * Add ndctl_dimm_get_dirty_shutdown() api
> 
> [1]: https://lists.01.org/pipermail/linux-nvdimm/2018-September/017890.html
> 
> ---
> 
> The latch mechanism is awkward especially when all that it needed is a
> rolling count of dirty-shutdown events. The expectation going forward is
> that the platform firmware will handle the latch, if it is present, and
> the OS need only consume the dirty-shutdown count. The ndctl
> implementation called libndctl apis from the udev queue which we
> discovered injects unnecessary udev queue drains / stalls into the boot
> path. Lastly, the userspace caching scheme for non-root users to consume
> the dirty-shutdown-count just isn't as efficient as teaching the kernel
> to cache this value and export it as a standard sysfs attribute.
> 
> ---
> 
> Dan Williams (3):
>       ndctl, lib: Add dirty-shutdown-count retrieval helper
>       ndctl: Revert "ndctl, intel: Fallback to smart cached shutdown_count"
>       ndctl: Revert "ndctl: Create ndctl udev rules for dirty shutdown"

These look good, applied.

> 
> 
>  .gitignore             |    1 
>  Makefile.am            |    3 -
>  configure.ac           |   10 ---
>  contrib/80-ndctl.rules |    3 -
>  ndctl.spec.in          |    3 -
>  ndctl/Makefile.am      |    5 --
>  ndctl/lib/intel.c      |   41 -------------
>  ndctl/lib/libndctl.c   |   16 ++++-
>  ndctl/lib/libndctl.sym |    5 ++
>  ndctl/lib/private.h    |    4 -
>  ndctl/libndctl.h       |    1 
>  ndctl/ndctl-udev.c     |  150 ------------------------------------------------
>  test/libndctl.c        |   29 +++++++--
>  13 files changed, 40 insertions(+), 231 deletions(-)
>  delete mode 100644 contrib/80-ndctl.rules
>  delete mode 100644 ndctl/ndctl-udev.c