This patch fixes the problem that system may stall if target's ->map_rq
returns DM_MAPIO_REQUEUE in map_request().
E.g. stall happens on 1 CPU box when a dm-mpath device with queue_if_no_path
bounces between all-paths-down and paths-up on I/O load.
When target's ->map_rq returns DM_MAPIO_REQUEUE, map_request() requeues
the request and returns to dm_request_fn(). Then, dm_request_fn()
doesn't exit the I/O dispatching loop and continues processing
the requeued request again.
This map and requeue loop can be done with interrupt disabled,
so 1 CPU system can be stalled if this situation happens.
For example, commands below can stall my 1 CPU box within 1 minute or so:
# dmsetup table mp
mp: 0 2097152 multipath 1 queue_if_no_path 0 1 1 service-time 0 1 2 8:144 1 1
# while true; do dd if=/dev/mapper/mp of=/dev/null bs=1M count=100; done &
# while true; do \
> dmsetup message mp 0 "fail_path 8:144" \
> dmsetup suspend --noflush mp \
> dmsetup resume mp \
> dmsetup message mp 0 "reinstate_path 8:144" \
> done
To fix the problem above, this patch changes dm_request_fn() to exit
the I/O dispatching loop once if a request is requeued in map_request().
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
When suspending a failed mirror, bios are completed by mirror_end_io() and
__rh_lookup() in dm_rh_dec() returns NULL where a non-NULL return value is
required by design. Fix this by not changing the state of the recovery failed
region from DM_RH_RECOVERING to DM_RH_NOSYNC in dm_rh_recovery_end().
Issue
On 2.6.33-rc1 kernel, I hit the bug when I suspended the failed
mirror by dmsetup command.
BUG: unable to handle kernel NULL pointer dereference at 00000020
IP: [<f94f38e2>] dm_rh_dec+0x35/0xa1 [dm_region_hash]
...
EIP: 0060:[<f94f38e2>] EFLAGS: 00010046 CPU: 0
EIP is at dm_rh_dec+0x35/0xa1 [dm_region_hash]
EAX: 00000286 EBX: 00000000 ECX: 00000286 EDX: 00000000
ESI: eff79eac EDI: eff79e80 EBP: f6915cd4 ESP: f6915cc4
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process dmsetup (pid: 2849, ti=f6914000 task=eff03e80 task.ti=f6914000)
...
Call Trace:
[<f9530af6>] ? mirror_end_io+0x53/0x1b1 [dm_mirror]
[<f9413104>] ? clone_endio+0x4d/0xa2 [dm_mod]
[<f9530aa3>] ? mirror_end_io+0x0/0x1b1 [dm_mirror]
[<f94130b7>] ? clone_endio+0x0/0xa2 [dm_mod]
[<c02d6bcb>] ? bio_endio+0x28/0x2b
[<f952f303>] ? hold_bio+0x2d/0x62 [dm_mirror]
[<f952f942>] ? mirror_presuspend+0xeb/0xf7 [dm_mirror]
[<c02aa3e2>] ? vmap_page_range+0xb/0xd
[<f9414c8d>] ? suspend_targets+0x2d/0x3b [dm_mod]
[<f9414ca9>] ? dm_table_presuspend_targets+0xe/0x10 [dm_mod]
[<f941456f>] ? dm_suspend+0x4d/0x150 [dm_mod]
[<f941767d>] ? dev_suspend+0x55/0x18a [dm_mod]
[<c0343762>] ? _copy_from_user+0x42/0x56
[<f9417fb0>] ? dm_ctl_ioctl+0x22c/0x281 [dm_mod]
[<f9417628>] ? dev_suspend+0x0/0x18a [dm_mod]
[<f9417d84>] ? dm_ctl_ioctl+0x0/0x281 [dm_mod]
[<c02c3c4b>] ? vfs_ioctl+0x22/0x85
[<c02c422c>] ? do_vfs_ioctl+0x4cb/0x516
[<c02c42b7>] ? sys_ioctl+0x40/0x5a
[<c0202858>] ? sysenter_do_call+0x12/0x28
Analysis
When recovery process of a region failed, dm_rh_recovery_end() function
changes the state of the region from RM_RH_RECOVERING to DM_RH_NOSYNC.
When recovery_complete() is executed between dm_rh_update_states() and
dm_writes() in do_mirror(), bios are processed with the region state,
DM_RH_NOSYNC. However, the region data is freed without checking its
pending count when dm_rh_update_states() is called next time.
When bios are finished by mirror_end_io(), __rh_lookup() in dm_rh_dec()
returns NULL even though a valid return value are expected.
Solution
Remove the state change of the recovery failed region from DM_RH_RECOVERING
to DM_RH_NOSYNC in dm_rh_recovery_end(). We can remove the state change
because:
- If the region data has been released by dm_rh_update_states(),
a new region data is created with the state of DM_RH_NOSYNC, and
bios are processed according to the DM_RH_NOSYNC state.
- If the region data has not been released by dm_rh_update_states(),
a state of the region is DM_RH_RECOVERING and bios are put in the
delayed_bio list.
The flag change from DM_RH_RECOVERING to DM_RH_NOSYNC in dm_rh_recovery_end()
was added in the following commit:
dm raid1: handle resync failures
author Jonathan Brassow <jbrassow@redhat.com>
Thu, 12 Jul 2007 16:29:04 +0000 (17:29 +0100)
http://git.kernel.org/linus/f44db678edcc6f4c2779ac43f63f0b9dfa28b724
Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
If the mirror log fails when the handle_errors option was not selected
and there is no remaining valid mirror leg, writes return success even
though they weren't actually written to any device. This patch
completes them with EIO instead.
This code path is taken:
do_writes:
bio_list_merge(&ms->failures, &sync);
do_failures:
if (!get_valid_mirror(ms)) (false)
else if (errors_handled(ms)) (false)
else bio_endio(bio, 0);
The logic in do_failures is based on presuming that the write was already
tried: if it succeeded at least on one leg (without handle_errors) it
is reported as success.
Reference: https://bugzilla.redhat.com/show_bug.cgi?id=555197
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch fixes two bugs that revolve around the miscalculation and
misuse of the variable 'overhead_size'. 'overhead_size' is the size of
the various header structures used during communication.
The first bug is the use of 'sizeof' with the pointer of a structure
instead of the structure itself - resulting in the wrong size being
computed. This is then used in a check to see if the payload
(data_size) would be to large for the preallocated structure. Since the
bug produces a smaller value for the overhead, it was possible for the
structure to be breached. (Although the current users of the code do
not currently send enough data to trigger this bug.)
The second bug is that the 'overhead_size' value is used to compute how
much of the preallocated space should be cleared before populating it
with fresh data. This should have simply been 'sizeof(struct cn_msg)'
not overhead_size. The fact that 'overhead_size' was computed
incorrectly made this problem "less bad" - leaving only a pointer's
worth of space at the end uncleared. Thus, this bug was never producing
a bad result, but still needs to be fixed - especially now that the
value is computed correctly.
Cc: stable@kernel.org
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
chunk_io() declares its 'struct mdata_req' on the stack and then
initializes its 'struct work_struct' member. Annotate the
initialization of this workqueue with INIT_WORK_ON_STACK to suppress a
debugobjects warning seen when CONFIG_DEBUG_OBJECTS_WORK is enabled.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
If a table containing zero as stripe count is passed into stripe_ctr
the code attempts to divide by zero.
This patch changes DM_TABLE_LOAD to return -EINVAL if the stripe count
is zero.
We now get the following error messages:
device-mapper: table: 253:0: striped: Invalid stripe count
device-mapper: ioctl: error adding target to table
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Collects several changes needed after applying
previous mpc5121 platform and driver patches:
- Add mpc5121 reset module node
- Clean up and fix NAND description, remove unused properties
here and correct NAND flash chip size.
- Clean up I2C nodes: remove obsolete "cell-index" properties,
add "fsl,preserve-clocking" property
- Add I2C RTC node for m41t61 RTC
- Add I2C nodes for AD7414 temperature sensor and AT24C32CD3 EEPROM
- Fix compatible property in DMA node
- Clean up CAN nodes, remove unused "cell-index" properties
- Fix compatible property in DIU node
- USB node changes:
- use "fsl,mpc5121-usb2-dr" compatible property only
- remove "port0" and "port1" properties as these are only used
for multi-port host(MHP) module which is not available
on MPC5121.
- use 'fsl,invert-drvvbus' and 'fsl,invert-pwr-fault' in
USB node for internal PHY to specify polarities
of the appropriate port pins.
Signed-off-by: Piotr Ziecik <kosmo@semihalf.com>
Signed-off-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Detlev Zundel <dzu@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Instantiate NAND Flash Controller device if it's
description is found in the device tree.
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Add support for MPC5121 real time clock module.
Signed-off-by: John Rigby <jcrigby@gmail.com>
Signed-off-by: Piotr Ziecik <kosmo@semihalf.com>
Signed-off-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Add reset module registers representation and
machine restart callback for mpc5121 platform.
Signed-off-by: Piotr Ziecik <kosmo@semihalf.com>
Signed-off-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Move mpc5121_clk_init() call to platform init code so it won't
get called on non-5121 platforms on a multiplatform kernel.
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Add DOUBLETAP to events emitted when in single touch only mode.
Users with a single touch firmware report not seeing the DOUBLETAP events; this
is a side effect of dropping old mapping for confidence. The confidence mapping
may be fine for singletouch mode but causes problems in multitouch mode.
Signed-off-by: Rafi Rubin <rafi@seas.upenn.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The 64-bit version of ELF_PLAT_INIT() clears TIF_IA32, but at this point
it has already been cleared by SET_PERSONALITY == set_personality_64bit.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The atomic ops emulation for 32bit legacy CPUs floods the tracer with
irq off/on entries. The irq disabled regions are short and therefor
not interesting when chasing long irq disabled latencies. Mark them
raw and keep them out of the trace.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Conflicts: kernel/sched.c
Necessary due to the urgent fixes which conflict with the code move
from sched.c to sched_fair.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The functions used to implement the TRACE_EVENT macro show up in
function tracing. This is considered a distraction, and these should
not be displayed. For example:
<idle>-0 [000] 57.202149: task_of <-update_stats_wait_end
<idle>-0 [000] 57.202149: ftrace_raw_event_sched_stat_wait <-update_stats_wait_end
<idle>-0 [000] 57.202150: ftrace_raw_event_id_sched_stat_template <-ftrace_raw_event_sched_stat_wait
<idle>-0 [000] 57.202150: sched_stat_wait: comm=sshd pid=2735 delay=19207 [ns]
The "ftrace_raw_event_*" traces are just the utility functions used
by TRACE_EVENT tracepoints.
Cc: Thomas Gleixner <tglx@linutronix.de>
Requested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Thomas found that due to ttwu() changing a task's cpu without holding
the rq->lock, task_rq_lock() might end up locking the wrong rq.
Avoid this by serializing against TASK_WAKING.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1266241712.15770.420.camel@laptop>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix a SMT scheduler performance regression that is leading to a scenario
where SMT threads in one core are completely idle while both the SMT threads
in another core (on the same socket) are busy.
This is caused by this commit (with the problematic code highlighted)
commit bdb94aa5db
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Tue Sep 1 10:34:38 2009 +0200
sched: Try to deal with low capacity
@@ -4203,15 +4223,18 @@ find_busiest_queue()
...
for_each_cpu(i, sched_group_cpus(group)) {
+ unsigned long power = power_of(i);
...
- wl = weighted_cpuload(i);
+ wl = weighted_cpuload(i) * SCHED_LOAD_SCALE;
+ wl /= power;
- if (rq->nr_running == 1 && wl > imbalance)
+ if (capacity && rq->nr_running == 1 && wl > imbalance)
continue;
On a SMT system, power of the HT logical cpu will be 589 and
the scheduler load imbalance (for scenarios like the one mentioned above)
can be approximately 1024 (SCHED_LOAD_SCALE). The above change of scaling
the weighted load with the power will result in "wl > imbalance" and
ultimately resulting in find_busiest_queue() return NULL, causing
load_balance() to think that the load is well balanced. But infact
one of the tasks can be moved to the idle core for optimal performance.
We don't need to use the weighted load (wl) scaled by the cpu power to
compare with imabalance. In that condition, we already know there is only a
single task "rq->nr_running == 1" and the comparison between imbalance,
wl is to make sure that we select the correct priority thread which matches
imbalance. So we really need to compare the imabalnce with the original
weighted load of the cpu and not the scaled load.
But in other conditions where we want the most hammered(busiest) cpu, we can
use scaled load to ensure that we consider the cpu power in addition to the
actual load on that cpu, so that we can move the load away from the
guy that is getting most hammered with respect to the actual capacity,
as compared with the rest of the cpu's in that busiest group.
Fix it.
Reported-by: Ma Ling <ling.ma@intel.com>
Initial-Analysis-by: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1266023662.2808.118.camel@sbs-t61.sc.intel.com>
Cc: stable@kernel.org [2.6.32.x]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix for sched_mc_powersavigs for pre-Nehalem platforms.
Child sched domain should clear SD_PREFER_SIBLING if parent will have
SD_POWERSAVINGS_BALANCE because they are contradicting.
Sets the flags correctly based on sched_mc_power_savings.
Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100208100555.GD2931@dirshya.in.ibm.com>
Cc: stable@kernel.org [2.6.32.x]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This cleans up the identification of multitouch groups and enables
the end of group sync.
Taps are now explicitly handled to adjust for the changes in the
event stream in multitouch mode. Added triple and quad tap for the
benefit of tools that recognize different tap types but do not have
full multi touch support.
This cleans up the behavior particularly for the latest firmware, which
didn't work particularly well with the older version of the driver.
In this form, when multitouch is active, both mt and st events will come out of
the "N-Trig MultiTouch" device. And when its not st events will come out of
"N-Trig Touchscreen".
Signed-off-by: Rafi Rubin <rafi@seas.upenn.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
With the pen and touch split apart, we no longer need to inject
additional tool switching events.
Signed-off-by: Rafi Rubin <rafi@seas.upenn.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Added a quirk to enable distinct input devices. The digitizer utilizes
three inputs to represent pen, multitouch and a normal touch screen.
With the Pen partitioned, it behaves well and does not need special
handling.
Also, I set names to the input devices to clarify the functions of the
various inputs.
Signed-off-by: Rafi Rubin <rafi@seas.upenn.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The __va()/__pa() offsets and the boot memory offsets are consistent for
all PMB users, so there is no need to special case these for legacy PMB.
Kill the special casing off and depend on CONFIG_PMB across the board.
This also fixes up yet another addressing bug for sh64.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The usbmixer proc file contains mapping between ALSA control API and
USB mixer control units. The purpose of this file is for debugging
and a problem diagnostics.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
