Linux-NVDIMM Archive on lore.kernel.org
 help / color / Atom feed
From: "Verma, Vishal L" <vishal.l.verma@intel.com>
To: "Williams, Dan J" <dan.j.williams@intel.com>
Cc: "Olson, Ben" <ben.olson@intel.com>,
	"linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
	"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
	"Biesek, Michal" <michal.biesek@intel.com>
Subject: Re: [ndctl PATCH 04/10] libdaxctl: add an API to determine if memory is movable
Date: Fri, 18 Oct 2019 19:57:07 +0000
Message-ID: <dfd1bdbaa41c3f6e97834d592b32bb10ba562c6a.camel@intel.com> (raw)
In-Reply-To: <CAPcyv4hb7vPbWhb3R5fyJH0H5OqRmhtVr=_D0tiYrkc_r8HpaQ@mail.gmail.com>


On Fri, 2019-10-18 at 11:54 -0700, Dan Williams wrote:
> On Wed, Oct 2, 2019 at 4:49 PM Vishal Verma <vishal.l.verma@intel.com> wrote:
> > By default, daxctl always attempts to online new memory sections as
> > 'movable' so that routine kernel allocations aren't serviced from this
> > memory, and the memory is later removable via hot-unplug.
> > 
> > System configuration, or other agents (such as udev rules) may race
> > 'daxctl' to online memory, and this may result in the memory not being
> > 'movable'. Add an interface to query the movability of a memory object
> > associated with a dax device.
> > 
> > This is in preparation to both display a 'movable' attribute in device
> > listings, as well as optionally allowing memory to be onlined as
> > non-movable.
> > 
> > Cc: Dan Williams <dan.j.williams@intel.com>
> > Reported-by: Ben Olson <ben.olson@intel.com>
> > Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
> > ---
> >  daxctl/lib/libdaxctl-private.h | 20 +++++++++
> >  daxctl/lib/libdaxctl.c         | 77 ++++++++++++++++++++++++++++++++--
> >  daxctl/lib/libdaxctl.sym       |  5 +++
> >  daxctl/libdaxctl.h             |  1 +
> >  4 files changed, 100 insertions(+), 3 deletions(-)
> > 
> > diff --git a/daxctl/lib/libdaxctl-private.h b/daxctl/lib/libdaxctl-private.h
> > index 7ba3c46..82939bb 100644
> > --- a/daxctl/lib/libdaxctl-private.h
> > +++ b/daxctl/lib/libdaxctl-private.h
> > @@ -44,6 +44,25 @@ enum memory_op {
> >         MEM_SET_ONLINE,
> >         MEM_IS_ONLINE,
> >         MEM_COUNT,
> > +       MEM_FIND_ZONE,
> 
> This is private so the naming is not too big a concern, but isn't this
> a MEM_GET_ZONE? A find operation to me is something that can succeed
> to find nothing, whereas a get operation fail assumes the association
> can always be retrieved barring exceptional conditions.

Hm, my personal view of find vs. get was that 'get' grabs a reference
(or similar) to something which we know how to get to (have a pointer
directly) etc. 'Find' is more of a 'go searching for' something - and it
may involve walking and looping over data structures.

But I'm not too opposed to this, and can change to 'get' if that follows
convention better.


_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org

  reply index

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-02 23:49 [ndctl PATCH 00/10] fixes and movability for system-ram mode Vishal Verma
2019-10-02 23:49 ` [ndctl PATCH 01/10] libdaxctl: refactor path construction in op_for_one_memblock() Vishal Verma
2019-10-18 18:43   ` Dan Williams
2019-10-02 23:49 ` [ndctl PATCH 02/10] libdaxctl: refactor memblock_is_online() checks Vishal Verma
2019-10-18 18:45   ` Dan Williams
2019-10-02 23:49 ` [ndctl PATCH 03/10] daxctl/device.c: fix json output omission for reconfigure-device Vishal Verma
2019-10-18 18:46   ` Dan Williams
2019-10-02 23:49 ` [ndctl PATCH 04/10] libdaxctl: add an API to determine if memory is movable Vishal Verma
2019-10-18 18:54   ` Dan Williams
2019-10-18 19:57     ` Verma, Vishal L [this message]
2019-10-18 20:40       ` Dan Williams
2019-10-02 23:49 ` [ndctl PATCH 05/10] libdaxctl: allow memblock_in_dev() to return an error Vishal Verma
2019-10-18 19:15   ` Dan Williams
2019-10-02 23:49 ` [ndctl PATCH 06/10] daxctl: show a 'movable' attribute in device listings Vishal Verma
2019-10-18 19:16   ` Dan Williams
2019-10-02 23:49 ` [ndctl PATCH 07/10] daxctl: detect races when onlining memory blocks Vishal Verma
2019-10-18 19:26   ` Dan Williams
2019-10-02 23:49 ` [ndctl PATCH 08/10] Documentation: clarify memory movablity for reconfigure-device Vishal Verma
2019-10-18 20:46   ` Dan Williams
2019-10-18 20:50     ` Verma, Vishal L
2019-10-02 23:49 ` [ndctl PATCH 09/10] libdaxctl: add an API to online memory in a non-movable state Vishal Verma
2019-10-18 20:54   ` Dan Williams
2019-10-02 23:49 ` [ndctl PATCH 10/10] daxctl: add --no-movable option for onlining memory Vishal Verma
2019-10-18 20:58   ` Dan Williams
2019-10-18 21:04     ` Verma, Vishal L
2019-10-18 21:25       ` Dan Williams

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=dfd1bdbaa41c3f6e97834d592b32bb10ba562c6a.camel@intel.com \
    --to=vishal.l.verma@intel.com \
    --cc=ben.olson@intel.com \
    --cc=dan.j.williams@intel.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=linux-nvdimm@lists.01.org \
    --cc=michal.biesek@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-NVDIMM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-nvdimm/0 linux-nvdimm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-nvdimm linux-nvdimm/ https://lore.kernel.org/linux-nvdimm \
		linux-nvdimm@lists.01.org
	public-inbox-index linux-nvdimm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.01.lists.linux-nvdimm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git