From: Peter Xu <peterx@redhat.com>
To: Axel Rasmussen <axelrasmussen@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
Andrea Arcangeli <aarcange@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Daniel Colascione <dancol@google.com>,
Hugh Dickins <hughd@google.com>,
Jerome Glisse <jglisse@redhat.com>, Joe Perches <joe@perches.com>,
Lokesh Gidra <lokeshgidra@google.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Mike Rapoport <rppt@linux.vnet.ibm.com>, Shaohua Li <shli@fb.com>,
Shuah Khan <shuah@kernel.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Wang Qing <wangqing@vivo.com>,
linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
linux-mm@kvack.org, Brian Geffon <bgeffon@google.com>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
Mina Almasry <almasrymina@google.com>,
Oliver Upton <oupton@google.com>
Subject: Re: [PATCH 3/9] userfaultfd/shmem: support minor fault registration for shmem
Date: Fri, 9 Apr 2021 12:50:24 -0400 [thread overview]
Message-ID: <20210409165024.GF792100@xz-x1> (raw)
In-Reply-To: <20210408234327.624367-4-axelrasmussen@google.com>
On Thu, Apr 08, 2021 at 04:43:21PM -0700, Axel Rasmussen wrote:
[...]
> @@ -1820,16 +1821,27 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
>
> page = pagecache_get_page(mapping, index,
> FGP_ENTRY | FGP_HEAD | FGP_LOCK, 0);
> - if (xa_is_value(page)) {
> + swapped = xa_is_value(page);
> + if (swapped) {
> error = shmem_swapin_page(inode, index, &page,
> sgp, gfp, vma, fault_type);
> if (error == -EEXIST)
> goto repeat;
> -
> *pagep = page;
> - return error;
> + if (error)
> + return error;
> }
>
> + if (page && vma && userfaultfd_minor(vma)) {
> + unlock_page(page);
> + put_page(page);
> + *fault_type = handle_userfault(vmf, VM_UFFD_MINOR);
> + return 0;
> + }
If we need to consider swapping for UFFDIO_CONTINUE later (as Hugh pointed out
previously, which looks the right thing to do), it's indeed a bit awkward to
swapin here. Maybe move this chunk to right after pagecache_get_page()
returns? Then no need to touch the rest.
> +
> + if (swapped)
> + return 0;
> +
> if (page)
> hindex = page->index;
> if (page && sgp == SGP_WRITE)
> --
> 2.31.1.295.g9ea45b61b8-goog
>
--
Peter Xu
next prev parent reply other threads:[~2021-04-09 16:50 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-08 23:43 [PATCH 0/9] userfaultfd: add minor fault handling for shmem Axel Rasmussen
2021-04-08 23:43 ` [PATCH 1/9] userfaultfd/hugetlbfs: avoid including userfaultfd_k.h in hugetlb.h Axel Rasmussen
2021-04-12 23:47 ` Peter Xu
2021-04-08 23:43 ` [PATCH 2/9] userfaultfd/shmem: combine shmem_{mcopy_atomic,mfill_zeropage}_pte Axel Rasmussen
2021-04-12 23:57 ` Peter Xu
2021-04-08 23:43 ` [PATCH 3/9] userfaultfd/shmem: support minor fault registration for shmem Axel Rasmussen
2021-04-09 16:50 ` Peter Xu [this message]
2021-04-08 23:43 ` [PATCH 4/9] userfaultfd/shmem: support UFFDIO_CONTINUE " Axel Rasmussen
2021-04-12 23:17 ` Peter Xu
2021-04-13 4:40 ` Axel Rasmussen
2021-04-13 18:12 ` Peter Xu
2021-04-15 18:18 ` Axel Rasmussen
2021-04-08 23:43 ` [PATCH 5/9] userfaultfd/selftests: use memfd_create for shmem test type Axel Rasmussen
2021-04-08 23:43 ` [PATCH 6/9] userfaultfd/selftests: create alias mappings in the shmem test Axel Rasmussen
2021-04-08 23:43 ` [PATCH 7/9] userfaultfd/selftests: reinitialize test context in each test Axel Rasmussen
2021-04-08 23:43 ` [PATCH 8/9] userfaultfd/selftests: exercise minor fault handling shmem support Axel Rasmussen
2021-04-08 23:43 ` [PATCH 9/9] userfaultfd/shmem: modify shmem_mcopy_atomic_pte to use install_ptes Axel Rasmussen
2021-04-09 5:04 ` [PATCH 0/9] userfaultfd: add minor fault handling for shmem Andrew Morton
2021-04-09 17:03 ` Axel Rasmussen
2021-04-09 21:18 ` Peter Xu
2021-04-09 22:16 ` Mike Kravetz
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=20210409165024.GF792100@xz-x1 \
--to=peterx@redhat.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=almasrymina@google.com \
--cc=axelrasmussen@google.com \
--cc=bgeffon@google.com \
--cc=dancol@google.com \
--cc=dgilbert@redhat.com \
--cc=hughd@google.com \
--cc=jglisse@redhat.com \
--cc=joe@perches.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=lokeshgidra@google.com \
--cc=mike.kravetz@oracle.com \
--cc=oupton@google.com \
--cc=rppt@linux.vnet.ibm.com \
--cc=sfr@canb.auug.org.au \
--cc=shli@fb.com \
--cc=shuah@kernel.org \
--cc=viro@zeniv.linux.org.uk \
--cc=wangqing@vivo.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).