Re: [PATCH 1/4] SCHED: add some "wait..on_bit...timeout()" interfaces.

On Thu, 18 Sep 2014 16:42:22 +0200 Peter Zijlstra [off-list ref]
wrote:

On Tue, Sep 16, 2014 at 03:31:35PM +1000, NeilBrown wrote:

quoted

In commit c1221321b7c25b53204447cff9949a6d5a7ddddc
   sched: Allow wait_on_bit_action() functions to support a timeout

I suggested that a "wait_on_bit_timeout()" interface would not meet my
need.  This isn't true - I was just over-engineering.

Including a 'private' field in wait_bit_key instead of a focused
"timeout" field was just premature generalization.  If some other
use is ever found, it can be generalized or added later.

So this patch renames "private" to "timeout" with a meaning "stop
waiting when "jiffies" reaches or passes "timeout",
and adds two of the many possible wait..bit..timeout() interfaces:

wait_on_page_bit_killable_timeout(), which is the one I want to use,
and out_of_line_wait_on_bit_timeout() which is a reasonably general
example.  Others can be added as needed.

Signed-off-by: NeilBrown <redacted>
---
 include/linux/pagemap.h |    2 ++
 include/linux/wait.h    |    5 ++++-
 kernel/sched/wait.c     |   36 ++++++++++++++++++++++++++++++++++++
 mm/filemap.c            |   13 +++++++++++++
 4 files changed, 55 insertions(+), 1 deletion(-)

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Thanks.
I assume that means it is OK for this patch to go to Linus via the NFS tree,
so we get to keep everything together.
Now I just need an Ack from akpm for the mm bits (please...)

NeilBrown