[RESEND PATCH 0/7] Add FOLL_LONGTERM to GUP fast and use it

Andrew Morton akpm at linux-foundation.org
Wed Mar 20 09:19:30 AEDT 2019

On Sun, 17 Mar 2019 11:34:31 -0700 ira.weiny at intel.com wrote:

> Resending after rebasing to the latest mm tree.
> HFI1, qib, and mthca, use get_user_pages_fast() due to it performance
> advantages.  These pages can be held for a significant time.  But
> get_user_pages_fast() does not protect against mapping FS DAX pages.
> Introduce FOLL_LONGTERM and use this flag in get_user_pages_fast() which
> retains the performance while also adding the FS DAX checks.  XDP has also
> shown interest in using this functionality.[1]
> In addition we change get_user_pages() to use the new FOLL_LONGTERM flag and
> remove the specialized get_user_pages_longterm call.

It would be helpful to include your response to Christoph's question
in the changelog.  Because if one person was wondering about this,
others will likely do so.

We have no record of acks or reviewed-by's.  At least one was missed
but that is very very partial.

This patchset is fairly DAX-centered, but Dan wasn't cc'ed!

So ho hum.  I'll scoop them up and shall make the above changes to the
[1/n] changelog, but we still have some work to do.

More information about the Linuxppc-dev mailing list