No need to call mpol_set_nodemask() when we have no context for the
mempolicy. This can occur when we're parsing a tmpfs 'mpol' mount option.
Just save the raw nodemask in the mempolicy's w.user_nodemask member for
use when a tmpfs/shmem file is created. mpol_shared_policy_init() will
"contextualize" the policy for the new file based on the creating task's
context.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lee's patch "mempolicy: use MPOL_PREFERRED for system-wide default policy"
has made the MPOL_DEFAULT only used in the memory policy APIs. So, no
need to check in __mpol_equal also. Also get rid of mpol_match_intent()
and move its logic directly into __mpol_equal().
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to reduce fragmentation, this patch classifies freed pages in two
groups according to their probability of being part of a high order merge.
Pages belonging to a compound whose next-highest buddy is free are more
likely to be part of a high order merge in the near future, so they will
be added at the tail of the freelist. The remaining pages are put at the
front of the freelist.
In this way, the pages that are more likely to cause a big merge are kept
free longer. Consequently there is a tendency to aggregate the
long-living allocations on a subset of the compounds, reducing the
fragmentation.
This heuristic was tested on three machines, x86, x86-64 and ppc64 with
3GB of RAM in each machine. The tests were kernbench, netperf, sysbench
and STREAM for performance and a high-order stress test for huge page
allocations.
KernBench X86
Elapsed mean 374.77 ( 0.00%) 375.10 (-0.09%)
User mean 649.53 ( 0.00%) 650.44 (-0.14%)
System mean 54.75 ( 0.00%) 54.18 ( 1.05%)
CPU mean 187.75 ( 0.00%) 187.25 ( 0.27%)
KernBench X86-64
Elapsed mean 94.45 ( 0.00%) 94.01 ( 0.47%)
User mean 323.27 ( 0.00%) 322.66 ( 0.19%)
System mean 36.71 ( 0.00%) 36.50 ( 0.57%)
CPU mean 380.75 ( 0.00%) 381.75 (-0.26%)
KernBench PPC64
Elapsed mean 173.45 ( 0.00%) 173.74 (-0.17%)
User mean 587.99 ( 0.00%) 587.95 ( 0.01%)
System mean 60.60 ( 0.00%) 60.57 ( 0.05%)
CPU mean 373.50 ( 0.00%) 372.75 ( 0.20%)
Nothing notable for kernbench.
NetPerf UDP X86
64 42.68 ( 0.00%) 42.77 ( 0.21%)
128 85.62 ( 0.00%) 85.32 (-0.35%)
256 170.01 ( 0.00%) 168.76 (-0.74%)
1024 655.68 ( 0.00%) 652.33 (-0.51%)
2048 1262.39 ( 0.00%) 1248.61 (-1.10%)
3312 1958.41 ( 0.00%) 1944.61 (-0.71%)
4096 2345.63 ( 0.00%) 2318.83 (-1.16%)
8192 4132.90 ( 0.00%) 4089.50 (-1.06%)
16384 6770.88 ( 0.00%) 6642.05 (-1.94%)*
NetPerf UDP X86-64
64 148.82 ( 0.00%) 154.92 ( 3.94%)
128 298.96 ( 0.00%) 312.95 ( 4.47%)
256 583.67 ( 0.00%) 626.39 ( 6.82%)
1024 2293.18 ( 0.00%) 2371.10 ( 3.29%)
2048 4274.16 ( 0.00%) 4396.83 ( 2.79%)
3312 6356.94 ( 0.00%) 6571.35 ( 3.26%)
4096 7422.68 ( 0.00%) 7635.42 ( 2.79%)*
8192 12114.81 ( 0.00%)* 12346.88 ( 1.88%)
16384 17022.28 ( 0.00%)* 17033.19 ( 0.06%)*
1.64% 2.73%
NetPerf UDP PPC64
64 49.98 ( 0.00%) 50.25 ( 0.54%)
128 98.66 ( 0.00%) 100.95 ( 2.27%)
256 197.33 ( 0.00%) 191.03 (-3.30%)
1024 761.98 ( 0.00%) 785.07 ( 2.94%)
2048 1493.50 ( 0.00%) 1510.85 ( 1.15%)
3312 2303.95 ( 0.00%) 2271.72 (-1.42%)
4096 2774.56 ( 0.00%) 2773.06 (-0.05%)
8192 4918.31 ( 0.00%) 4793.59 (-2.60%)
16384 7497.98 ( 0.00%) 7749.52 ( 3.25%)
The tests are run to have confidence limits within 1%. Results marked
with a * were not confident although in this case, it's only outside by
small amounts. Even with some results that were not confident, the
netperf UDP results were generally positive.
NetPerf TCP X86
64 652.25 ( 0.00%)* 648.12 (-0.64%)*
23.80% 22.82%
128 1229.98 ( 0.00%)* 1220.56 (-0.77%)*
21.03% 18.90%
256 2105.88 ( 0.00%) 1872.03 (-12.49%)*
1.00% 16.46%
1024 3476.46 ( 0.00%)* 3548.28 ( 2.02%)*
13.37% 11.39%
2048 4023.44 ( 0.00%)* 4231.45 ( 4.92%)*
9.76% 12.48%
3312 4348.88 ( 0.00%)* 4396.96 ( 1.09%)*
6.49% 8.75%
4096 4726.56 ( 0.00%)* 4877.71 ( 3.10%)*
9.85% 8.50%
8192 4732.28 ( 0.00%)* 5777.77 (18.10%)*
9.13% 13.04%
16384 5543.05 ( 0.00%)* 5906.24 ( 6.15%)*
7.73% 8.68%
NETPERF TCP X86-64
netperf-tcp-vanilla-netperf netperf-tcp
tcp-vanilla pgalloc-delay
64 1895.87 ( 0.00%)* 1775.07 (-6.81%)*
5.79% 4.78%
128 3571.03 ( 0.00%)* 3342.20 (-6.85%)*
3.68% 6.06%
256 5097.21 ( 0.00%)* 4859.43 (-4.89%)*
3.02% 2.10%
1024 8919.10 ( 0.00%)* 8892.49 (-0.30%)*
5.89% 6.55%
2048 10255.46 ( 0.00%)* 10449.39 ( 1.86%)*
7.08% 7.44%
3312 10839.90 ( 0.00%)* 10740.15 (-0.93%)*
6.87% 7.33%
4096 10814.84 ( 0.00%)* 10766.97 (-0.44%)*
6.86% 8.18%
8192 11606.89 ( 0.00%)* 11189.28 (-3.73%)*
7.49% 5.55%
16384 12554.88 ( 0.00%)* 12361.22 (-1.57%)*
7.36% 6.49%
NETPERF TCP PPC64
netperf-tcp-vanilla-netperf netperf-tcp
tcp-vanilla pgalloc-delay
64 594.17 ( 0.00%) 596.04 ( 0.31%)*
1.00% 2.29%
128 1064.87 ( 0.00%)* 1074.77 ( 0.92%)*
1.30% 1.40%
256 1852.46 ( 0.00%)* 1856.95 ( 0.24%)
1.25% 1.00%
1024 3839.46 ( 0.00%)* 3813.05 (-0.69%)
1.02% 1.00%
2048 4885.04 ( 0.00%)* 4881.97 (-0.06%)*
1.15% 1.04%
3312 5506.90 ( 0.00%) 5459.72 (-0.86%)
4096 6449.19 ( 0.00%) 6345.46 (-1.63%)
8192 7501.17 ( 0.00%) 7508.79 ( 0.10%)
16384 9618.65 ( 0.00%) 9490.10 (-1.35%)
There was a distinct lack of confidence in the X86* figures so I included
what the devation was where the results were not confident. Many of the
results, whether gains or losses were within the standard deviation so no
solid conclusion can be reached on performance impact. Looking at the
figures, only the X86-64 ones look suspicious with a few losses that were
outside the noise. However, the results were so unstable that without
knowing why they vary so much, a solid conclusion cannot be reached.
SYSBENCH X86
sysbench-vanilla pgalloc-delay
1 7722.85 ( 0.00%) 7756.79 ( 0.44%)
2 14901.11 ( 0.00%) 13683.44 (-8.90%)
3 15171.71 ( 0.00%) 14888.25 (-1.90%)
4 14966.98 ( 0.00%) 15029.67 ( 0.42%)
5 14370.47 ( 0.00%) 14865.00 ( 3.33%)
6 14870.33 ( 0.00%) 14845.57 (-0.17%)
7 14429.45 ( 0.00%) 14520.85 ( 0.63%)
8 14354.35 ( 0.00%) 14362.31 ( 0.06%)
SYSBENCH X86-64
1 17448.70 ( 0.00%) 17484.41 ( 0.20%)
2 34276.39 ( 0.00%) 34251.00 (-0.07%)
3 50805.25 ( 0.00%) 50854.80 ( 0.10%)
4 66667.10 ( 0.00%) 66174.69 (-0.74%)
5 66003.91 ( 0.00%) 65685.25 (-0.49%)
6 64981.90 ( 0.00%) 65125.60 ( 0.22%)
7 64933.16 ( 0.00%) 64379.23 (-0.86%)
8 63353.30 ( 0.00%) 63281.22 (-0.11%)
9 63511.84 ( 0.00%) 63570.37 ( 0.09%)
10 62708.27 ( 0.00%) 63166.25 ( 0.73%)
11 62092.81 ( 0.00%) 61787.75 (-0.49%)
12 61330.11 ( 0.00%) 61036.34 (-0.48%)
13 61438.37 ( 0.00%) 61994.47 ( 0.90%)
14 62304.48 ( 0.00%) 62064.90 (-0.39%)
15 63296.48 ( 0.00%) 62875.16 (-0.67%)
16 63951.76 ( 0.00%) 63769.09 (-0.29%)
SYSBENCH PPC64
-sysbench-pgalloc-delay-sysbench
sysbench-vanilla pgalloc-delay
1 7645.08 ( 0.00%) 7467.43 (-2.38%)
2 14856.67 ( 0.00%) 14558.73 (-2.05%)
3 21952.31 ( 0.00%) 21683.64 (-1.24%)
4 27946.09 ( 0.00%) 28623.29 ( 2.37%)
5 28045.11 ( 0.00%) 28143.69 ( 0.35%)
6 27477.10 ( 0.00%) 27337.45 (-0.51%)
7 26489.17 ( 0.00%) 26590.06 ( 0.38%)
8 26642.91 ( 0.00%) 25274.33 (-5.41%)
9 25137.27 ( 0.00%) 24810.06 (-1.32%)
10 24451.99 ( 0.00%) 24275.85 (-0.73%)
11 23262.20 ( 0.00%) 23674.88 ( 1.74%)
12 24234.81 ( 0.00%) 23640.89 (-2.51%)
13 24577.75 ( 0.00%) 24433.50 (-0.59%)
14 25640.19 ( 0.00%) 25116.52 (-2.08%)
15 26188.84 ( 0.00%) 26181.36 (-0.03%)
16 26782.37 ( 0.00%) 26255.99 (-2.00%)
Again, there is little to conclude here. While there are a few losses,
the results vary by +/- 8% in some cases. They are the results of most
concern as there are some large losses but it's also within the variance
typically seen between kernel releases.
The STREAM results varied so little and are so verbose that I didn't
include them here.
The final test stressed how many huge pages can be allocated. The
absolute number of huge pages allocated are the same with or without the
page. However, the "unusability free space index" which is a measure of
external fragmentation was slightly lower (lower is better) throughout the
lifetime of the system. I also measured the latency of how long it took
to successfully allocate a huge page. The latency was slightly lower and
on X86 and PPC64, more huge pages were allocated almost immediately from
the free lists. The improvement is slight but there.
[mel@csn.ul.ie: Tested, reworked for less branches]
[czoccolo@gmail.com: fix oops by checking pfn_valid_within()]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Corrado Zoccolo <czoccolo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shaohua Li reported parallel file copy on tmpfs can lead to OOM killer.
This is regression of caused by commit 9ff473b9a7 ("vmscan: evict
streaming IO first"). Wow, It is 2 years old patch!
Currently, tmpfs file cache is inserted active list at first. This means
that the insertion doesn't only increase numbers of pages in anon LRU, but
it also reduces anon scanning ratio. Therefore, vmscan will get totally
confused. It scans almost only file LRU even though the system has plenty
unused tmpfs pages.
Historically, lru_cache_add_active_anon() was used for two reasons.
1) Intend to priotize shmem page rather than regular file cache.
2) Intend to avoid reclaim priority inversion of used once pages.
But we've lost both motivation because (1) Now we have separate anon and
file LRU list. then, to insert active list doesn't help such priotize.
(2) In past, one pte access bit will cause page activation. then to
insert inactive list with pte access bit mean higher priority than to
insert active list. Its priority inversion may lead to uninteded lru
chun. but it was already solved by commit 645747462 (vmscan: detect
mapped file pages used only once). (Thanks Hannes, you are great!)
Thus, now we can use lru_cache_add_anon() instead.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Shaohua Li <shaohua.li@intel.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fix the following 'make includecheck' warnings:
arch/xtensa/kernel/vectors.S: asm/processor.h is included more than once.
arch/xtensa/kernel/vectors.S: asm/ptrace.h is included more than once.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The port data structure related to fc_host statistics collection is
not initialized. This causes system crash when reading the fc_host
statistics. The fix is to initialize port structure during driver
attach.
Signed-off-by: Krishna Gudipati <kgudipat@brocade.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
There is no need to call sk_sleep before calling wake_up_interruptible,
because the wait_queue_head is now with the socket.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
The async helper threads offload crc work onto all the
CPUs, and make streaming writes much faster. This
changes the O_DIRECT write code to use them. The only
small complication was that we need to pass in the
logical offset in the file for each bio, because we can't
find it in the bio's pages.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Yan Zheng noticed two places we were doing a lot of work
without task->state set to TASK_RUNNING. This sets the state
properly after we get ready to sleep but decide not to.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
In order for AIO to work, we need to implement aio_write. This patch converts
our btrfs_file_write to btrfs_aio_write. I've tested this with xfstests and
nothing broke, and the AIO stuff magically started working. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This provides basic DIO support for reading and writing. It does not do the
work to recover from mismatching checksums, that will come later. A few design
changes have been made from Jim's code (sorry Jim!)
1) Use the generic direct-io code. Jim originally re-wrote all the generic DIO
code in order to account for all of BTRFS's oddities, but thanks to that work it
seems like the best bet is to just ignore compression and such and just opt to
fallback on buffered IO.
2) Fallback on buffered IO for compressed or inline extents. Jim's code did
it's own buffering to make dio with compressed extents work. Now we just
fallback onto normal buffered IO.
3) Use ordered extents for the writes so that all of the
lock_extent()
lookup_ordered()
type checks continue to work.
4) Do the lock_extent() lookup_ordered() loop in readpage so we don't race with
DIO writes.
I've tested this with fsx and everything works great. This patch depends on my
dio and filemap.c patches to work. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Btrfs cannot handle having logically non-contiguous requests submitted. For
example if you have
Logical: [0-4095][HOLE][8192-12287]
Physical: [0-4095] [4096-8191]
Normally the DIO code would put these into the same BIO's. The problem is we
need to know exactly what offset is associated with what BIO so we can do our
checksumming and unlocking properly, so putting them in the same BIO doesn't
work. So add another check where we submit the current BIO if the physical
blocks are not contigous OR the logical blocks are not contiguous.
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Because BTRFS can do RAID and such, we need our own submit hook so we can setup
the bio's in the correct fashion, and handle checksum errors properly. So there
are a few changes here
1) The submit_io hook. This is straightforward, just call this instead of
submit_bio.
2) Allow the fs to return -ENOTBLK for reads. Usually this has only worked for
writes, since writes can fallback onto buffered IO. But BTRFS needs the option
of falling back on buffered IO if it encounters a compressed extent, since we
need to read the entire extent in and decompress it. So if we get -ENOTBLK back
from get_block we'll return back and fallback on buffered just like the write
case.
I've tested these changes with fsx and everything seems to work. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This is similar to what already happens in the write case. If we have a short
read while doing O_DIRECT, instead of just returning, fallthrough and try to
read the rest via buffered IO. BTRFS needs this because if we encounter a
compressed or inline extent during DIO, we need to fallback on buffered. If the
extent is compressed we need to read the entire thing into memory and
de-compress it into the users pages. I have tested this with fsx and everything
works great. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This patch adds metadata ENOSPC handling for the balance code.
It is consisted by following major changes:
1. Avoid COW tree leave in the phrase of merging tree.
2. Handle interaction with snapshot creation.
3. make the backref cache can live across transactions.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Pre-allocate space for data relocation. This can detect ENOPSC
condition caused by fragmentation of free space.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Previous patches make the allocater return -ENOSPC if there is no
unreserved free metadata space. This patch updates tree log code
and various other places to propagate/handle the ENOSPC error.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Introduce metadata reservation context for delayed allocation
and update various related functions.
This patch also introduces EXTENT_FIRST_DELALLOC control bit for
set/clear_extent_bit. It tells set/clear_bit_hook whether they
are processing the first extent_state with EXTENT_DELALLOC bit
set. This change is important if set/clear_extent_bit involves
multiple extent_state.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Besides simplify the code, this change makes sure all metadata
reservation for normal metadata operations are released after
committing transaction.
Changes since V1:
Add code that check if unlink and rmdir will free space.
Add ENOSPC handling for clone ioctl.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Introducing metadata reseravtion contexts has two major advantages.
First, it makes metadata reseravtion more traceable. Second, it can
reclaim freed space and re-add them to the itself after transaction
committed.
Besides add btrfs_block_rsv structure and related helper functions,
This patch contains following changes:
Move code that decides if freed tree block should be pinned into
btrfs_free_tree_block().
Make space accounting more accurate, mainly for handling read only
block groups.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Shrink delayed allocation space in a synchronized manner is more
controllable than flushing all delay allocated space in an async
thread.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We already have fs_info->chunk_mutex to avoid concurrent
chunk creation.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The size of reserved space is stored in space_info. If block groups
of different raid types are linked to separate space_info, changing
allocation profile will corrupt reserved space accounting.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The TRACE_EVENT() macros automate creation of trace events. To automate
initialization, the set up variables are loaded in a special section
that is read on boot up. GCC is not aware that these static variables
are used and will complain about them if we do not inform GCC that
they are indeed used.
One of the declarations of the event element was missing a __used
annotation. This patch adds it.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow userspace filesystem implementation to use splice() to read from
the fuse device.
The userspace filesystem can now transfer data coming from a WRITE
request to an arbitrary file descriptor (regular file, block device or
socket) without having to go through a userspace buffer.
The semantics of using splice() to read messages are:
1) with a single splice() call move the whole message from the fuse
device to a temporary pipe
2) read the header from the pipe and determine the message type
3a) if message is a WRITE then splice data from pipe to destination
3b) else read rest of message to userspace buffer
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
When splicing buffers to the fuse device with SPLICE_F_MOVE, try to
move pages from the pipe buffer into the page cache. This allows
populating the fuse filesystem's cache without ever touching the page
contents, i.e. zero copy read capability.
The following steps are performed when trying to move a page into the
page cache:
- buf->ops->confirm() to make sure the new page is uptodate
- buf->ops->steal() to try to remove the new page from it's previous place
- remove_from_page_cache() on the old page
- add_to_page_cache_locked() on the new page
If any of the above steps fail (non fatally) then the code falls back
to copying the page. In particular ->steal() will fail if there are
external references (other than the page cache and the pipe buffer) to
the page.
Also since the remove_from_page_cache() + add_to_page_cache_locked()
are non-atomic it is possible that the page cache is repopulated in
between the two and add_to_page_cache_locked() will fail. This could
be fixed by creating a new atomic replace_page_cache_page() function.
fuse_readpages_end() needed to be reworked so it works even if
page->mapping is NULL for some or all pages which can happen if the
add_to_page_cache_locked() failed.
A number of sanity checks were added to make sure the stolen pages
don't have weird flags set, etc... These could be moved into generic
splice/steal code.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Allow userspace filesystem implementation to use splice() to write to
the fuse device. The semantics of using splice() are:
1) buffer the message header and data in a temporary pipe
2) with a *single* splice() call move the message from the temporary pipe
to the fuse device
The READ reply message has the most interesting use for this, since
now the data from an arbitrary file descriptor (which could be a
regular file, a block device or a socket) can be tranferred into the
fuse device without having to go through a userspace buffer. It will
also allow zero copy moving of pages.
One caveat is that the protocol on the fuse device requires the length
of the whole message to be written into the header. But the length of
the data transferred into the temporary pipe may not be known in
advance. The current library implementation works around this by
using vmplice to write the header and modifying the header after
splicing the data into the pipe (error handling omitted):
struct fuse_out_header out;
iov.iov_base = &out;
iov.iov_len = sizeof(struct fuse_out_header);
vmsplice(pip[1], &iov, 1, 0);
len = splice(input_fd, input_offset, pip[1], NULL, len, 0);
/* retrospectively modify the header: */
out.len = len + sizeof(struct fuse_out_header);
splice(pip[0], NULL, fuse_chan_fd(req->ch), NULL, out.len, flags);
This works since vmsplice only saves a pointer to the data, it does
not copy the data itself.
Since pipes are currently limited to 16 pages and messages need to be
spliced atomically, the length of the data is limited to 15 pages (or
60kB for 4k pages).
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acquire a page ref on pages in ->readpages() and release them when the
read has finished. Not acquiring a reference didn't seem to cause any
trouble since the page is locked and will not be kicked out of the
page cache during the read.
However the following patches will want to remove the page from the
cache so a separate ref is needed. Making the reference in req->pages
explicit also makes the code easier to understand.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Replace uses of get_user_pages() with get_user_pages_fast(). It looks
nicer and should be faster in most cases.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
"map" isn't needed any more after: 0bd87182d3 "fuse: fix kunmap in
fuse_ioctl_copy_user"
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Commit 5f487cd34f (power_supply: Use
attribute groups) causes a regression the power supply core does not
export the 'type' attribute anymore.
POWER_SUPPLY_PROP_TYPE is handled by the power supply core without the
low-level driver, so power_supply_attr_is_visible() must always return
the entry as readable.
Reported-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Patch b7e2ecef92 (perf, trace: Optimize tracepoints by removing
IRQ-disable from perf/tracepoint interaction) made the
unfortunate mistake of assuming the world is x86 only, correct
this.
The problem was that perf_fetch_caller_regs() did
local_save_flags() into regs->flags, and I re-used that to
remove another local_save_flags(), forgetting !x86 doesn't have
regs->flags.
Do the reverse, remove the local_save_flags() from
perf_fetch_caller_regs() and let the ftrace site do the
local_save_flags() instead.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: acme@redhat.com
Cc: efault@gmx.de
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1274778175.5882.623.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On Mon, 2010-05-17 at 17:34 +0200, Mark Brown wrote:
> This doesn't seem like the right error handling - if the driver has a
> set_mode() you'd *expect* it to have a get_mode() but there's no need
> for it to be a strict requirement.
True. In such a case, even a valid request would be lost! So now
in the updated patch:
- check if get_mode is present to avoid oops;
- if get_mode is not present, proceed anyways for the request.
Here is the updated patch:
>From bad0d5eb51ef84be5b100e3dd0f5a590ea0529b6 Mon Sep 17 00:00:00 2001
From: Sundar R Iyer <sundar.iyer@stericsson.com>
Date: Fri, 14 May 2010 15:14:17 +0530
Subject: [PATCH 1/1] regulator: return set_mode when same mode is requested
save I/O costs by returning when the same mode is
requested for the regulator
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Sundar R Iyer <sundar.iyer@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
All twl6030 regulators can be programmed from 1.0v to 3.3v
with 100mV steps.
The below formula can be used to calculate the vsel values
to be programmed in the VREG_VOLTAGE registers.
Voltage(in mV) = 1000mv + 100mv * (vsel - 1)
Ex: if vsel = 0x9, mV = 1000 + 100 * (9 -1) = 1800mV.
This patch removes all existing VSEL tables for twl6030 adjustable
regulators and just uses the formula directly for vsel calculations
after verifing they fall in the allowed range.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
