Will be used from external places in the upcoming c2c patch series.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1474558645-19956-9-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Will be used from external places in the upcoming c2c patch series.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1474558645-19956-8-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Will be used from external places in the upcoming c2c patch series.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1474558645-19956-7-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Will be used from external places in the upcoming c2c patch series.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1474558645-19956-6-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Will be used from external places in the upcoming c2c patch series.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1474558645-19956-5-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add __hist_entry__snprintf() to take a perf_hpp_list as an argument
instead of using he->hists->hpp_list.
This way we can display arbitrary list of entries regardless of the
hists setup, which will be useful in the upcoming c2c patch series.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1474558645-19956-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Using the PMU::set_drv_config() callback to enable the CoreSight sink
that will be used for the trace session.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1474041004-13956-8-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Now that the required mechanic is there to deal with PMU specific
configuration, add the functionality to the tools where events can be
selected.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1474041004-13956-7-git-send-email-mathieu.poirier@linaro.org
[ Fix the build on XSI-compliant systems, using str_error_r() to make sure we return a string, not an integer ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Some architectures require an additional load to find the address of
percpu pointers. In some implemenatations, the C aliasing rules do not
allow the result of that load to be kept over the store that modifies
the percpu variable, which causes additional loads.
Work around this by finding the pointer first, then operating on that.
It's also possible to mark things as restrict and those kind of games,
but that can require larger and arch specific changes.
On powerpc, __this_cpu_inc_return compiles to:
ld 10,48(13)
ldx 9,3,10
addi 9,9,1
stdx 9,3,10
ld 9,48(13)
ldx 3,9,3
With this patch it compiles to:
ld 10,48(13)
ldx 9,3,10
addi 9,9,1
stdx 9,3,10
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
To: Tejun Heo <tj@kernel.org>
To: Christoph Lameter <cl@linux.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
This avoids some low-level operations.
It has the benefit that now register values van be read from /sys/kernel/debug/regmap
The maximum register value is just a guess - all higher addresses read as zero.
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Now that there is a i2c_client, use the more specific dev for logging.
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Now that all users of legacy attach are converted it can be removed.
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
cx231xx does not yet support attaching new-style i2c_client DVB demod
drivers. Add necessary code base on tuner support for i2c_client.
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Afterwards it is possible to convert attaching in card drivers.
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
When si2165_init fails, the clk values in state are still at zero.
But the dvb-core ignores the return value of init will call tune
afterwards.
This will trigger a division by zero when tuning.
At least check for the variables to be non-zero before dividing.
This happened for a system with WinTV HVR-4400 PCIe-card after suspend-to-disk.
Do suspend-to-disk without accessing the DVB device before.
After wakeup try to tune.
si2165_init fails at checking the chip_mode and aborts.
Then si2165_set_if_freq_shift will fail with div-by-zero.
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Such fallback string is present in the 'soc_camera' version of the R-Car VIN
driver, so need to add it here as well...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
inside lgdt3306a_search we reading demod status 20 times with 50 msec sleep after each read.
This gives us more than 1 sec of delay. Removing this delay should not affect demod functionality.
Signed-off-by: Abylay Ospan <aospan@netup.ru>
Acked-by: Michael Ira Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
asm-generic is only intended for architecture defaults, and we can simply
kill it off by moving the two defintions directly to <linux/libata.h>.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently when doing a DAX hole punch with ext4 we fail to do a writeback.
This is because the logic around filemap_write_and_wait_range() in
ext4_punch_hole() only looks for dirty page cache pages in the radix tree,
not for dirty DAX exceptional entries.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The workqueue "_irq_audio_queues" runs the audio upstream handler.
It has a single work item(&dev->_audio_work_entry) and hence doesn't
require ordering. Also, it is not being used on a memory reclaim path.
Hence, the singlethreaded workqueue has been replaced with the use of
system_wq.
System workqueues have been able to handle high level of concurrency
for a long time now and hence it's not required to have a singlethreaded
workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue
created with create_singlethread_workqueue(), system_wq allows multiple
work items to overlap executions even on the same CPU; however, a
per-cpu workqueue doesn't have any CPU locality or global ordering
guarantee unless the target CPU is explicitly specified and thus the
increase of local concurrency shouldn't make any difference.
The work item has been flushed in cx25821_stop_upstream_audio() to ensure
that nothing is pending when the driver is disconnected.
Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Pull networking fixes from David Miller:
"Mostly small bits scattered all over the place, which is usually how
things go this late in the -rc series.
1) Proper driver init device resets in bnx2, from Baoquan He.
2) Fix accounting overflow in __tcp_retransmit_skb(),
sk_forward_alloc, and ip_idents_reserve, from Eric Dumazet.
3) Fix crash in bna driver ethtool stats handling, from Ivan Vecera.
4) Missing check of skb_linearize() return value in mac80211, from
Johannes Berg.
5) Endianness fix in nf_table_trace dumps, from Liping Zhang.
6) SSN comparison fix in SCTP, from Marcelo Ricardo Leitner.
7) Update DSA and b44 MAINTAINERS entries.
8) Make input path of vti6 driver work again, from Nicolas Dichtel.
9) Off-by-one in mlx4, from Sebastian Ott.
10) Fix fallback route lookup handling in ipv6, from Vincent Bernat.
11) Fix stack corruption on probe in qed driver, from Yuval Mintz.
12) PHY init fixes in r8152 from Hayes Wang.
13) Missing SKB free in irda_accept error path, from Phil Turnbull"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (61 commits)
tcp: properly account Fast Open SYN-ACK retrans
tcp: fix under-accounting retransmit SNMP counters
MAINTAINERS: Update b44 maintainer.
net: get rid of an signed integer overflow in ip_idents_reserve()
net/mlx4_core: Fix to clean devlink resources
net: can: ifi: Configure transmitter delay
vti6: fix input path
ipmr, ip6mr: return lastuse relative to now
r8152: disable ALDPS and EEE before setting PHY
r8152: remove r8153_enable_eee
r8152: move PHY settings to hw_phy_cfg
r8152: move enabling PHY
r8152: move some functions
cxgb4/cxgb4vf: Allocate more queues for 25G and 100G adapter
qed: Fix stack corruption on probe
MAINTAINERS: Add an entry for the core network DSA code
net: ipv6: fallback to full lookup if table lookup is unsuitable
net/mlx5: E-Switch, Handle mode change failures
net/mlx5: E-Switch, Fix error flow in the SRIOV e-switch init code
net/mlx5: Fix flow counter bulk command out mailbox allocation
...
Workqueues shouldn't be freed. destroy_workqueue should be used instead.
destroy_workqueue safely destroys a workqueue and ensures that all pending
work items are done before destroying the workqueue.
Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Scan response data should not be updated unless there
is an advertising instance.
Signed-off-by: Michał Narajowski <michal.narajowski@codecoup.pl>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
if specified DVB-C bandwidth not supported then force 8MHz.
Should work for most cases.
Signed-off-by: Abylay Ospan <aospan@netup.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Add these options as module parameters for now; should other drivers
need similar options we could add it to the LIRC api.
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This is a duplicate of the timeout in rc_dev.
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Thomas has reported a lockdep splat hitting in
add_transaction_credits(). The problem is that that function calls
jbd2_might_wait_for_commit() while holding j_state_lock which is wrong
(we do not really wait for transaction commit while holding that lock).
Fix the problem by moving jbd2_might_wait_for_commit() into places where
we are ready to wait for transaction commit and thus j_state_lock is
unlocked.
Cc: stable@vger.kernel.org
Fixes: 1eaa566d36
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Two cases:
1) blk_mq_alloc_request() needlessly re-runs the queue, after
calling into the tag allocation without NOWAIT set. We don't
need to do that.
2) blk_mq_map_request() should just use blk_mq_run_hw_queue() with
the async flag set to false.
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Added function to read BER for ISDB-T
Also SNR values fixed for ISDB-T
Signed-off-by: Abylay Ospan <aospan@netup.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Tha ARM randconfig builds came up with another rare build failure
for the dib3000mc driver, when dvb-usb-dibusb-mb is built-in and
dib3000mc is a loadable module:
ERROR: "dibusb_dib3000mc_frontend_attach" [drivers/media/usb/dvb-usb/dvb-usb-nova-t-usb2.ko] undefined!
ERROR: "dibusb_dib3000mc_tuner_attach" [drivers/media/usb/dvb-usb/dvb-usb-nova-t-usb2.ko] undefined!
Apparently this used to be a valid configuration (build-time, not
run-time), but broke as part of a cleanup.
I tried reverting the cleanup, but saw that the code was still wrong
then. This version adds a dependency for dib3000mb, to ensure that
dib3000mb does not force the dibusb_dib3000mc_frontend_attach function
to be built-in when dib3000mc is a loadable module.
I have also checked the two other files that were changed in the original
cleanup, and found them to be correct in either version, so I do not
touch that part.
As this is a rather obscure bug, there is no need for backports.
Fixes: 028c70ff42 ("[media] dvb-usb/dvb-usb-v2: use IS_ENABLED")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Tha ARM randconfig builds came up with another rare build failure
for the dib3000mc driver, when dvb-usb-dibusb-mb is built-in and
dib3000mc is a loadable module:
ERROR: "dibusb_dib3000mc_frontend_attach" [drivers/media/usb/dvb-usb/dvb-usb-nova-t-usb2.ko] undefined!
ERROR: "dibusb_dib3000mc_tuner_attach" [drivers/media/usb/dvb-usb/dvb-usb-nova-t-usb2.ko] undefined!
Apparently this used to be a valid configuration (build-time, not
run-time), but broke as part of a cleanup.
I tried reverting the cleanup, but saw that the code was still wrong
then. This tries to fix the code properly, by moving the problematic
functions into a new file that now is built as a loadable module or
built-in, whichever is correct for a particular configuration. It fixes
the regression as well as the runtime problem that already existed.
The new module dependency chain is now:
dvb-usb-{dibusb_mc,a800,dib0700,umt-010,gp8psk} dvb-usb-dibusb-mb
| | | |
dvb-usb-dibusb-mc-common | ___________| |
| | | | |
dib3000mc (frontend) | | | dib3000mb (frontend)
| | |
| | |
dvb-usb-dibusb-common
I have also checked the two other files that were changed in the original
cleanup, and found them to be correct in either version, so I do not
touch that part.
As this is a rather obscure bug, there is no need for backports.
Fixes: 028c70ff42 ("[media] dvb-usb/dvb-usb-v2: use IS_ENABLED")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Add the missing platform_device_del() before return from
lirc_parallel_init() in the error handling case.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
ensure multiple separate register reads are from the same snapshot
Signed-off-by: Abylay Ospan <aospan@netup.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This patch adds a PMU callback and the required mechanic so that drivers
can process the command line configuration elements found in
evsel::config_terms.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1474041004-13956-6-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Coresight ETMs are IP blocks used to perform HW assisted tracing on a
CPU core. This patch introduce the required auxiliary API functions
allowing the perf core to interact with a tracer.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1474041004-13956-4-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The __get_cpuid() test is only valid when compiling for x86. When
compiling for other architectures like ARM/ARM64 the test fails event if
the functionality is not required.
This patch isolate the build-in feature check to x86 platform, allowing
the compilation and usage of PMUs that use the AUXTRACE infrastructure
on other architectures (i.e ARM CoreSight).
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1474041004-13956-2-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use cond_resched() like everybody else.
Mikulas explained why dm_bufio_cond_resched() was introduced to begin
with (hopefully cond_resched can be improved accordingly) here:
https://www.redhat.com/archives/dm-devel/2016-September/msg00112.html
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com> # added last comment in header
As the documentation for kthread_stop() says, "if threadfn() may call
do_exit() itself, the caller must ensure task_struct can't go away".
dm-crypt does not ensure this and therefore crashes when crypt_dtr()
calls kthread_stop(). The crash is trivially reproducible by adding a
delay before the call to kthread_stop() and just opening and closing a
dm-crypt device.
general protection fault: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 533 Comm: cryptsetup Not tainted 4.8.0-rc7+ #7
task: ffff88003bd0df40 task.stack: ffff8800375b4000
RIP: 0010: kthread_stop+0x52/0x300
Call Trace:
crypt_dtr+0x77/0x120
dm_table_destroy+0x6f/0x120
__dm_destroy+0x130/0x250
dm_destroy+0x13/0x20
dev_remove+0xe6/0x120
? dev_suspend+0x250/0x250
ctl_ioctl+0x1fc/0x530
? __lock_acquire+0x24f/0x1b10
dm_ctl_ioctl+0x13/0x20
do_vfs_ioctl+0x91/0x6a0
? ____fput+0xe/0x10
? entry_SYSCALL_64_fastpath+0x5/0xbd
? trace_hardirqs_on_caller+0x151/0x1e0
SyS_ioctl+0x41/0x70
entry_SYSCALL_64_fastpath+0x1f/0xbd
This problem was introduced by bcbd94ff48 ("dm crypt: fix a possible
hang due to race condition on exit").
Looking at the description of that patch (excerpted below), it seems
like the problem it addresses can be solved by just using
set_current_state instead of __set_current_state, since we obviously
need the memory barrier.
| dm crypt: fix a possible hang due to race condition on exit
|
| A kernel thread executes __set_current_state(TASK_INTERRUPTIBLE),
| __add_wait_queue, spin_unlock_irq and then tests kthread_should_stop().
| It is possible that the processor reorders memory accesses so that
| kthread_should_stop() is executed before __set_current_state(). If
| such reordering happens, there is a possible race on thread
| termination: [...]
So this patch just reverts the aforementioned patch and changes the
__set_current_state(TASK_INTERRUPTIBLE) to set_current_state(...). This
fixes the crash and should also fix the potential hang.
Fixes: bcbd94ff48 ("dm crypt: fix a possible hang due to race condition on exit")
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This change offers a pretty significant performance improvement.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
More efficient way to iterate an array due to prefetching (makes use of
the new dm_btree_cursor_* api).
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This uses prefetching to speed up iteration through a btree.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>