From: John Hubbard <jhubbard@nvidia.com>
To: Christoph Hellwig <hch@infradead.org>,
Pingfan Liu <kernelfans@gmail.com>
Cc: <linux-mm@kvack.org>, Ira Weiny <ira.weiny@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Mike Rapoport <rppt@linux.ibm.com>,
Dan Williams <dan.j.williams@intel.com>,
Matthew Wilcox <willy@infradead.org>,
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>,
Keith Busch <keith.busch@intel.com>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCHv2 1/2] mm/gup: fix omission of check on FOLL_LONGTERM in get_user_pages_fast()
Date: Mon, 3 Jun 2019 11:43:11 -0700 [thread overview]
Message-ID: <e389551e-32c3-c9f2-2861-1a8819dc7cc9@nvidia.com> (raw)
In-Reply-To: <20190603164206.GB29719@infradead.org>
On 6/3/19 9:42 AM, Christoph Hellwig wrote:
>> +#if defined(CONFIG_CMA)
>
> You can just use #ifdef here.
>
>> +static inline int reject_cma_pages(int nr_pinned, unsigned int gup_flags,
>> + struct page **pages)
>
> Please use two instead of one tab to indent the continuing line of
> a function declaration.
>
>> +{
>> + if (unlikely(gup_flags & FOLL_LONGTERM)) {
>
> IMHO it would be a little nicer if we could move this into the caller.
>
It does feel wrong-ish to loop through potentially every page that
gup_fast just followed. But could you clarify what you had in mind just
a bit more detail? For example, in qib_user_sdma_pin_pages() we have:
ret = get_user_pages_fast(addr, j, FOLL_LONGTERM, pages);
Should this call a filter routine to avoid CMA pages, is that it?
thanks,
--
John Hubbard
NVIDIA
next prev parent reply other threads:[~2019-06-03 18:43 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-03 6:34 Pingfan Liu
2019-06-03 6:34 ` [PATCHv2 2/2] mm/gup: rename nr as nr_pinned " Pingfan Liu
2019-06-03 15:02 ` Ira Weiny
2019-06-03 15:00 ` [PATCHv2 1/2] mm/gup: fix omission of check on FOLL_LONGTERM " Ira Weiny
2019-06-03 16:42 ` Christoph Hellwig
2019-06-03 18:43 ` John Hubbard [this message]
2019-06-03 23:56 ` Ira Weiny
2019-06-04 7:08 ` Christoph Hellwig
2019-06-04 7:24 ` Pingfan Liu
2019-06-04 16:55 ` Ira Weiny
2019-06-04 19:38 ` John Hubbard
2019-06-04 19:29 ` John Hubbard
2019-06-04 7:13 ` Pingfan Liu
2019-06-04 7:17 ` Christoph Hellwig
2019-06-04 7:20 ` Pingfan Liu
Reply instructions:
You may reply publicly 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=e389551e-32c3-c9f2-2861-1a8819dc7cc9@nvidia.com \
--to=jhubbard@nvidia.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.ibm.com \
--cc=dan.j.williams@intel.com \
--cc=hch@infradead.org \
--cc=ira.weiny@intel.com \
--cc=keith.busch@intel.com \
--cc=kernelfans@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=rppt@linux.ibm.com \
--cc=willy@infradead.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox