From: Al Viro <viro@ZenIV.linux.org.uk>
To: Ingo Molnar <mingo@kernel.org>
Cc: Jerome Glisse <j.glisse@gmail.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Boaz Harrosh <boaz@plexistor.com>, Jan Kara <jack@suse.cz>,
Mike Snitzer <snitzer@redhat.com>, Neil Brown <neilb@suse.de>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Chris Mason <clm@fb.com>, Paul Mackerras <paulus@samba.org>,
"H. Peter Anvin" <hpa@zytor.com>, Christoph Hellwig <hch@lst.de>,
Alasdair Kergon <agk@redhat.com>,
"linux-nvdimm@lists.01.org" <linux-nvdimm@ml01.01.org>,
Mel Gorman <mgorman@suse.de>,
Matthew Wilcox <willy@linux.intel.com>,
Ross Zwisler <ross.zwisler@linux.intel.com>,
Rik van Riel <riel@redhat.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Jens Axboe <axboe@kernel.dk>, Theodore Ts'o <tytso@mit.edu>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Julia Lawall <Julia.Lawall@lip6.fr>, Tejun Heo <tj@kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
paulmck@linux.vnet.ibm.com
Subject: Re: [PATCH v2 00/10] evacuate struct page from the block layer, introduce __pfn_t
Date: Fri, 8 May 2015 10:20:44 +0100 [thread overview]
Message-ID: <20150508092044.GH889@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20150508053759.GA25786@gmail.com>
On Fri, May 08, 2015 at 07:37:59AM +0200, Ingo Molnar wrote:
> same as iov_iter_get_pages(), except that pages array is allocated
> (kmalloc if possible, vmalloc if that fails) and left for caller to
> free. Lustre and NFS ->direct_IO() switched to it.
>
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
>
> So if code does iov_iter_get_pages_alloc() on a user address that has
> a real struct page behind it - and some other code does a regular
> get_user_pages() on it, we'll have two sets of struct page
> descriptors, the 'real' one, and a fake allocated one, right?
Huh? iov_iter_get_pages() is given an array of pointers to struct page,
which it fills with what it finds. iov_iter_get_pages_alloc() *allocates*
such an array, fills that with what it finds and gives the allocated array
to caller.
We are not allocating any struct page instances in either of those.
next prev parent reply other threads:[~2015-05-08 9:20 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-06 20:04 [PATCH v2 00/10] evacuate struct page from the block layer, introduce __pfn_t Dan Williams
2015-05-06 20:04 ` [PATCH v2 01/10] arch: introduce __pfn_t for persistent memory i/o Dan Williams
2015-05-07 14:55 ` Stephen Rothwell
2015-05-08 0:21 ` Dan Williams
2015-05-06 20:05 ` [PATCH v2 02/10] block: add helpers for accessing a bio_vec page Dan Williams
2015-05-08 15:59 ` Dan Williams
2015-05-06 20:05 ` [PATCH v2 03/10] block: convert .bv_page to .bv_pfn bio_vec Dan Williams
2015-05-06 20:05 ` [PATCH v2 04/10] dma-mapping: allow archs to optionally specify a ->map_pfn() operation Dan Williams
2015-05-06 20:05 ` [PATCH v2 05/10] scatterlist: use sg_phys() Dan Williams
2015-05-06 20:05 ` [PATCH v2 06/10] scatterlist: support "page-less" (__pfn_t only) entries Dan Williams
2015-05-06 20:05 ` [PATCH v2 07/10] x86: support dma_map_pfn() Dan Williams
2015-05-06 20:05 ` [PATCH v2 08/10] x86: support kmap_atomic_pfn_t() for persistent memory Dan Williams
2015-05-06 20:20 ` [Linux-nvdimm] " Dan Williams
2015-05-06 20:05 ` [PATCH v2 09/10] dax: convert to __pfn_t Dan Williams
2015-05-06 20:05 ` [PATCH v2 10/10] block: base support for pfn i/o Dan Williams
2015-05-06 22:10 ` [PATCH v2 00/10] evacuate struct page from the block layer, introduce __pfn_t Linus Torvalds
2015-05-06 23:47 ` Dan Williams
2015-05-07 0:19 ` Linus Torvalds
2015-05-07 2:36 ` Dan Williams
2015-05-07 9:02 ` Ingo Molnar
2015-05-07 14:42 ` Ingo Molnar
2015-05-07 15:52 ` Dan Williams
2015-05-07 17:52 ` Ingo Molnar
2015-05-07 15:00 ` Linus Torvalds
2015-05-07 15:40 ` Dan Williams
2015-05-07 15:58 ` Linus Torvalds
2015-05-07 16:03 ` Dan Williams
2015-05-07 17:36 ` Ingo Molnar
2015-05-07 17:42 ` Dan Williams
2015-05-07 17:56 ` Dave Hansen
2015-05-07 19:11 ` Ingo Molnar
2015-05-07 19:36 ` Jerome Glisse
2015-05-07 19:48 ` Ingo Molnar
2015-05-07 19:53 ` Ingo Molnar
2015-05-07 20:18 ` Jerome Glisse
2015-05-08 5:37 ` Ingo Molnar
2015-05-08 9:20 ` Al Viro [this message]
2015-05-08 9:26 ` Ingo Molnar
2015-05-08 10:00 ` Al Viro
2015-05-08 13:45 ` Rik van Riel
2015-05-08 14:05 ` Ingo Molnar
2015-05-08 14:54 ` Rik van Riel
[not found] ` <21836.51957.715473.780762@quad.stoffel.home>
2015-05-08 15:54 ` Linus Torvalds
2015-05-08 16:28 ` Al Viro
2015-05-08 16:59 ` Rik van Riel
2015-05-09 1:14 ` Linus Torvalds
2015-05-09 3:02 ` Rik van Riel
2015-05-09 3:52 ` Linus Torvalds
2015-05-09 21:56 ` Dave Chinner
2015-05-09 8:45 ` "Directly mapped persistent memory page cache" Ingo Molnar
2015-05-09 18:24 ` Dan Williams
2015-05-10 9:46 ` Ingo Molnar
2015-05-10 17:29 ` Dan Williams
[not found] ` <87r3qpyciy.fsf@x220.int.ebiederm.org>
2015-05-10 10:07 ` Ingo Molnar
2015-05-11 8:25 ` Dave Chinner
2015-05-11 9:18 ` Ingo Molnar
2015-05-11 10:12 ` Zuckerman, Boris
2015-05-11 10:38 ` Ingo Molnar
2015-05-12 0:53 ` Dave Chinner
2015-05-12 14:47 ` Jerome Glisse
2015-06-05 5:43 ` Dan Williams
2015-05-11 14:31 ` Matthew Wilcox
2015-05-11 20:01 ` Jerome Glisse
2015-05-07 17:43 ` [PATCH v2 00/10] evacuate struct page from the block layer, introduce __pfn_t Linus Torvalds
2015-05-07 20:06 ` Dan Williams
2015-05-07 16:18 ` Christoph Hellwig
2015-05-07 16:41 ` Dan Williams
2015-05-07 18:40 ` Ingo Molnar
2015-05-07 19:44 ` Dan Williams
2015-05-07 17:30 ` Jerome Glisse
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=20150508092044.GH889@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=Julia.Lawall@lip6.fr \
--cc=agk@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=axboe@kernel.dk \
--cc=benh@kernel.crashing.org \
--cc=boaz@plexistor.com \
--cc=clm@fb.com \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=hch@lst.de \
--cc=heiko.carstens@de.ibm.com \
--cc=hpa@zytor.com \
--cc=j.glisse@gmail.com \
--cc=jack@suse.cz \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nvdimm@ml01.01.org \
--cc=martin.petersen@oracle.com \
--cc=mgorman@suse.de \
--cc=mingo@kernel.org \
--cc=neilb@suse.de \
--cc=paulmck@linux.vnet.ibm.com \
--cc=paulus@samba.org \
--cc=riel@redhat.com \
--cc=ross.zwisler@linux.intel.com \
--cc=schwidefsky@de.ibm.com \
--cc=snitzer@redhat.com \
--cc=tj@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=tytso@mit.edu \
--cc=willy@linux.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
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;
as well as URLs for NNTP newsgroup(s).