Minor refactoring, to get rid of some duplicated code
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes the retry-based AIO infrastructure now that nothing in tree
is using it.
We want to remove retry-based AIO because it is fundemantally unsafe.
It retries IO submission from a kernel thread that has only assumed the
mm of the submitting task. All other task_struct references in the IO
submission path will see the kernel thread, not the submitting task.
This design flaw means that nothing of any meaningful complexity can use
retry-based AIO.
This removes all the code and data associated with the retry machinery.
The most significant benefit of this is the removal of the locking
around the unused run list in the submission path.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Signed-off-by: Zach Brown <zab@redhat.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes the only in-tree user of aio retry. This will let us
remove the retry code from the aio core.
Removing retry is relatively easy as the USB gadget wasn't using it to
retry IOs at all. It always fully submitted the IO in the context of
the initial io_submit() call. It only used the AIO retry facility to
get the submitter's mm context for copying the result of a read back to
user space. This is easy to implement with use_mm() and a work struct,
much like kvm does with async_pf_execute() for get_user_pages().
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bunch of performance improvements and cleanups Zach Brown and I have
been working on. The code should be pretty solid at this point, though
it could of course use more review and testing.
The results in my testing are pretty impressive, particularly when an
ioctx is being shared between multiple threads. In my crappy synthetic
benchmark, with 4 threads submitting and one thread reaping completions,
I saw overhead in the aio code go from ~50% (mostly ioctx lock
contention) to low single digits. Performance with ioctx per thread
improved too, but I'd have to rerun those benchmarks.
The reason I've been focused on performance when the ioctx is shared is
that for a fair number of real world completions, userspace needs the
completions aggregated somehow - in practice people just end up
implementing this aggregation in userspace today, but if it's done right
we can do it much more efficiently in the kernel.
Performance wise, the end result of this patch series is that submitting
a kiocb writes to _no_ shared cachelines - the penalty for sharing an
ioctx is gone there. There's still going to be some cacheline
contention when we deliver the completions to the aio ringbuffer (at
least if you have interrupts being delivered on multiple cores, which
for high end stuff you do) but I have a couple more patches not in this
series that implement coalescing for that (by taking advantage of
interrupt coalescing). With that, there's basically no bottlenecks or
performance issues to speak of in the aio code.
This patch:
use_mm() is used in more places than just aio. There's no need to mention
callers when describing the function.
Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current kernel returns -EINVAL unless a given mmap length is
"almost" hugepage aligned. This is because in sys_mmap_pgoff() the
given length is passed to vm_mmap_pgoff() as it is without being aligned
with hugepage boundary.
This is a regression introduced in commit 40716e2924 ("hugetlbfs: fix
alignment of huge page requests"), where alignment code is pushed into
hugetlb_file_setup() and the variable len in caller side is not changed.
To fix this, this patch partially reverts that commit, and adds
alignment code in caller side. And it also introduces hstate_sizelog()
in order to get proper hstate to specified hugepage size.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=56881
[akpm@linux-foundation.org: fix warning when CONFIG_HUGETLB_PAGE=n]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: <iceman_dvd@yahoo.com>
Cc: Steven Truelove <steven.truelove@utoronto.ca>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This exports the amount of anonymous transparent hugepages for each
memcg via the new "rss_huge" stat in memory.stat. The units are in
bytes.
This is helpful to determine the hugepage utilization for individual
jobs on the system in comparison to rss and opportunities where
MADV_HUGEPAGE may be helpful.
The amount of anonymous transparent hugepages is also included in "rss"
for backwards compatibility.
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit v3.9-rc1-53-g6d0cda9 "lguest: cache last cpu we ran on." missed
one case, which causes a triple fault. The guest calls guest_set_pgd()
on the top page, and we carefully remap the Switcher text page. But
we didn't reset last_host_cpu, so map_switcher_in_guest() thinks
the guest's regs and IDT/GDT etc are already mapped.
Reported-by: Paul Bolle <pebolle@tiscali.nl>
Tested-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I badly screwed up the merge in commit 6fa52ed33b ("Merge tag
'drivers-for-linus' of git://git.kernel.org/pub/.../arm-soc") by
incorrectly taking the arch/arm/mach-omap2/* data fully from the merge
target because the 'drivers-for-linus' branch seemed to be a proper
superset of the duplicate ARM commits.
That was bogus: commit ff931c821b ("ARM: OMAP: clocks: Delay clk inits
atleast until slab is initialized") only existed in head, and the
changes to arch/arm/mach-omap2/timer.c from that commit got list.
Re-doing the merge more carefully, I do think this part was the only
thing I screwed up. Knock wood.
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shamelessly copied from dchinner's:
ad650f5b xfs: fallback to vmalloc for large buffers in xfs_attrmulti_attr_get
xfsdump uses a large buffer for extended attributes, which has a
kmalloc'd shadow buffer in the kernel. This can fail after the
system has been running for some time as it is a high order
allocation. Add a fallback to vmalloc so that it doesn't require
contiguous memory and so won't randomly fail while xfsdump is
running.
This was done for xfs_attrlist_by_handle but
xfs_compat_attrlist_by_handle (the 32-bit version) needs the same
attention.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Shamelessly copied from dchinner's:
ad650f5b xfs: fallback to vmalloc for large buffers in xfs_attrmulti_attr_get
xfsdump uses for a large buffer for extended attributes, which has a
kmalloc'd shadow buffer in the kernel. This can fail after the
system has been running for some time as it is a high order
allocation. Add a fallback to vmalloc so that it doesn't require
contiguous memory and so won't randomly fail while xfsdump is
running.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Running a CONFIG_XFS_DEBUG kernel in production environments is not
the best idea as it introduces significant overhead, can change
the behaviour of algorithms (such as allocation) to improve test
coverage, and (most importantly) panic the machine on non-fatal
errors.
There are many cases where all we want to do is run a
kernel with more bounds checking enabled, such as is provided by the
ASSERT() statements throughout the code, but without all the
potential overhead and drawbacks.
This patch converts all the ASSERT statements to evaluate as
WARN_ON(1) statements and hence if they fail dump a warning and a
stack trace to the log. This has minimal overhead and does not
change any algorithms, and will allow us to find strange "out of
bounds" problems more easily on production machines.
There are a few places where assert statements contain debug only
code. These are converted to be debug-or-warn only code so that we
still get all the assert checks in the code.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Populate struct soc_info with the data that describes our RAM window.
As memory detection fails on RT5350 we read the amount of available memory
from the system controller.
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/5180/
Depending on the actual SoC we have a different base address as well as minimum
and maximum size for RAM. Add these fields to the per SoC structure.
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/5179/
