From: ira.weiny@intel.com
To: John Hubbard <jhubbard@nvidia.com>,
Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Jason Gunthorpe <jgg@ziepe.ca>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
"David S. Miller" <davem@davemloft.net>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Rich Felker <dalias@libc.org>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Ralf Baechle <ralf@linux-mips.org>,
Paul Burton <paul.burton@mips.com>,
James Hogan <jhogan@kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-s390@vger.kernel.org, linux-sh@vger.kernel.org,
sparclinux@vger.kernel.org, kvm-ppc@vger.kernel.org,
kvm@vger.kernel.org, linux-fpga@vger.kernel.org,
dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org,
linux-media@vger.kernel.org, linux-scsi@vger.kernel.org,
devel@driverdev.osuosl.org,
virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-fbdev@vger.kernel.org,
xen-devel@lists.xenproject.org, devel@lists.orangefs.org,
ceph-devel@vger.kernel.org, rds-devel@oss.oracle.com
Subject: [RESEND PATCH 4/7] mm/gup: Add FOLL_LONGTERM capability to GUP fast
Date: Tue, 19 Feb 2019 21:30:37 -0800 [thread overview]
Message-ID: <20190220053040.10831-5-ira.weiny@intel.com> (raw)
In-Reply-To: <20190220053040.10831-1-ira.weiny@intel.com>
From: Ira Weiny <ira.weiny@intel.com>
DAX pages were previously unprotected from longterm pins when users
called get_user_pages_fast().
Use the new FOLL_LONGTERM flag to check for DEVMAP pages and fall
back to regular GUP processing if a DEVMAP page is encountered.
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
mm/gup.c | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/mm/gup.c b/mm/gup.c
index 6f32d36b3c5b..f7e759c523bb 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1439,6 +1439,9 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
goto pte_unmap;
if (pte_devmap(pte)) {
+ if (unlikely(flags & FOLL_LONGTERM))
+ goto pte_unmap;
+
pgmap = get_dev_pagemap(pte_pfn(pte), pgmap);
if (unlikely(!pgmap)) {
undo_dev_pagemap(nr, nr_start, pages);
@@ -1578,8 +1581,11 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
if (!pmd_access_permitted(orig, flags & FOLL_WRITE))
return 0;
- if (pmd_devmap(orig))
+ if (pmd_devmap(orig)) {
+ if (unlikely(flags & FOLL_LONGTERM))
+ return 0;
return __gup_device_huge_pmd(orig, pmdp, addr, end, pages, nr);
+ }
refs = 0;
page = pmd_page(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
@@ -1904,8 +1910,20 @@ int get_user_pages_fast(unsigned long start, int nr_pages,
start += nr << PAGE_SHIFT;
pages += nr;
- ret = get_user_pages_unlocked(start, nr_pages - nr, pages,
- gup_flags);
+ if (gup_flags & FOLL_LONGTERM) {
+ down_read(¤t->mm->mmap_sem);
+ ret = __gup_longterm_locked(current, current->mm,
+ start, nr_pages - nr,
+ pages, NULL, gup_flags);
+ up_read(¤t->mm->mmap_sem);
+ } else {
+ /*
+ * retain FAULT_FOLL_ALLOW_RETRY optimization if
+ * possible
+ */
+ ret = get_user_pages_unlocked(start, nr_pages - nr,
+ pages, gup_flags);
+ }
/* Have to be a bit careful with return values */
if (nr > 0) {
--
2.20.1
next prev parent reply other threads:[~2019-02-20 5:31 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-20 5:30 [RESEND PATCH 0/7] Add FOLL_LONGTERM to GUP fast and use it ira.weiny
2019-02-20 5:30 ` [RESEND PATCH 1/7] mm/gup: Replace get_user_pages_longterm() with FOLL_LONGTERM ira.weiny
2019-02-20 5:30 ` [RESEND PATCH 2/7] mm/gup: Change write parameter to flags in fast walk ira.weiny
2019-02-20 5:30 ` [RESEND PATCH 3/7] mm/gup: Change GUP fast to use flags rather than a write 'bool' ira.weiny
2019-02-20 19:29 ` Mike Marshall
2019-02-21 3:18 ` Souptick Joarder
2019-02-21 22:24 ` Ira Weiny
2019-02-20 5:30 ` ira.weiny [this message]
2019-02-20 5:30 ` [RESEND PATCH 5/7] IB/hfi1: Use the new FOLL_LONGTERM flag to get_user_pages_fast() ira.weiny
2019-02-20 5:30 ` [RESEND PATCH 6/7] IB/qib: " ira.weiny
2019-02-20 5:30 ` [RESEND PATCH 7/7] IB/mthca: " ira.weiny
2019-02-20 15:19 ` [RESEND PATCH 0/7] Add FOLL_LONGTERM to GUP fast and use it Christoph Hellwig
2019-02-20 18:02 ` Ira Weiny
2019-02-27 19:14 ` Ira Weiny
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=20190220053040.10831-5-ira.weiny@intel.com \
--to=ira.weiny@intel.com \
--cc=akpm@linux-foundation.org \
--cc=benh@kernel.crashing.org \
--cc=bp@alien8.de \
--cc=ceph-devel@vger.kernel.org \
--cc=dalias@libc.org \
--cc=davem@davemloft.net \
--cc=devel@driverdev.osuosl.org \
--cc=devel@lists.orangefs.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=heiko.carstens@de.ibm.com \
--cc=jgg@ziepe.ca \
--cc=jhogan@kernel.org \
--cc=jhubbard@nvidia.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=kvm-ppc@vger.kernel.org \
--cc=kvm@vger.kernel.org \
--cc=linux-fbdev@vger.kernel.org \
--cc=linux-fpga@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=linux-mips@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-rdma@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=linux-sh@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mhocko@suse.com \
--cc=mingo@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=paul.burton@mips.com \
--cc=paulus@samba.org \
--cc=peterz@infradead.org \
--cc=ralf@linux-mips.org \
--cc=rds-devel@oss.oracle.com \
--cc=schwidefsky@de.ibm.com \
--cc=sparclinux@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=virtualization@lists.linux-foundation.org \
--cc=xen-devel@lists.xenproject.org \
--cc=ysato@users.sourceforge.jp \
/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).