The current check does not take into account the previous value of
pinned_vm; thus it is quite bogus as is. Fix this by checking the
new value after the (optimistic) atomic inc.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The driver uses mmap_sem for both pinned_vm accounting and
get_user_pages(). Because rdma drivers might want to use gup_longterm() in
the future we still need some sort of mmap_sem serialization (as opposed
to removing it entirely by using gup_fast()). Now that pinned_vm is atomic
the writer lock can therefore be converted to reader.
This also fixes a bug that __qib_get_user_pages was not taking into
account the current value of pinned_vm.
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Taking a sleeping lock to _only_ increment a variable is quite the
overkill, and pretty much all users do this. Furthermore, some drivers
(ie: infiniband and scif) that need pinned semantics can go to quite
some trouble to actually delay via workqueue (un)accounting for pinned
pages when not possible to acquire it.
By making the counter atomic we no longer need to hold the mmap_sem and
can simply some code around it for pinned_vm users. The counter is 64-bit
such that we need not worry about overflows such as rdma user input
controlled from userspace.
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Similar to the core change commit 5f1d43de54 ("IB/core: disable memory
registration of filesystem-dax vmas")
PSM should be prevented from using filesystem DAX pages.
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This removes the 'write' and 'force' from get_user_pages() and replaces
them with 'gup_flags' to make the use of FOLL_FORCE explicit in callers
as use of this flag can result in surprising behaviour (and hence bugs)
within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We will soon modify the vanilla get_user_pages() so it can no
longer be used on mm/tasks other than 'current/current->mm',
which is by far the most common way it is called. For now,
we allow the old-style calls, but warn when they are used.
(implemented in previous patch)
This patch switches all callers of:
get_user_pages()
get_user_pages_unlocked()
get_user_pages_locked()
to stop passing tsk/mm so they will no longer see the warnings.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: jack@suse.cz
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210156.113E9407@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The static helper routine, __qib_get_user_pages(), accepts a vma arg,
but current use always passes NULL.
This has caused some confusion associated with the correct use of this
argument, but since the current use case doesn't require the
flexiblity, the best thing to do is to simplfy the code to always pass
NULL to get_user_pages().
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Some kernel components pin user space memory (infiniband and perf) (by
increasing the page count) and account that memory as "mlocked".
The difference between mlocking and pinning is:
A. mlocked pages are marked with PG_mlocked and are exempt from
swapping. Page migration may move them around though.
They are kept on a special LRU list.
B. Pinned pages cannot be moved because something needs to
directly access physical memory. They may not be on any
LRU list.
I recently saw an mlockalled process where mm->locked_vm became
bigger than the virtual size of the process (!) because some
memory was accounted for twice:
Once when the page was mlocked and once when the Infiniband
layer increased the refcount because it needt to pin the RDMA
memory.
This patch introduces a separate counter for pinned pages and
accounts them seperately.
Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Mike Marciniszyn <infinipath@qlogic.com>
Cc: Roland Dreier <roland@kernel.org>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In most cases, get_user_pages and get_user_pages_fast should be used
to pin user pages in memory. But sometimes, some special flags except
FOLL_GET, FOLL_WRITE and FOLL_FORCE are needed, for example in
following patch, KVM needs FOLL_HWPOISON. To support these users,
__get_user_pages is exported directly.
There are some symbol name conflicts in infiniband driver, fixed them too.
Signed-off-by: Huang Ying <ying.huang@intel.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Michel Lespinasse <walken@google.com>
CC: Roland Dreier <roland@kernel.org>
CC: Ralph Campbell <infinipath@qlogic.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Add a low-level IB driver for QLogic PCIe adapters.
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
