I've been asked a few times about how to find out what is calling
some location in the kernel. One way is to use dynamic function tracing
and implement the func_stack_trace. But this only finds out who is
calling a particular function. It does not tell you who is calling
that function and entering a specific if conditional.
I have myself implemented a quick version of trace_dump_stack() for
this purpose a few times, and just needed it now. This is when I realized
that this would be a good tool to have in the kernel like trace_printk().
Using trace_dump_stack() is similar to dump_stack() except that it
writes to the trace buffer instead and can be used in critical locations.
For example:
@@ -5485,8 +5485,12 @@ need_resched_nonpreemptible:
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
if (unlikely(signal_pending_state(prev->state, prev)))
prev->state = TASK_RUNNING;
- else
+ else {
deactivate_task(rq, prev, 1);
+ trace_printk("Deactivating task %s:%d\n",
+ prev->comm, prev->pid);
+ trace_dump_stack();
+ }
switch_count = &prev->nvcsw;
}
Produces:
<...>-3249 [001] 296.105269: schedule: Deactivating task ntpd:3249
<...>-3249 [001] 296.105270: <stack trace>
=> schedule
=> schedule_hrtimeout_range
=> poll_schedule_timeout
=> do_select
=> core_sys_select
=> sys_select
=> system_call_fastpath
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
DMA_CTRL_ACK's description applies to its clear state, not to its set state.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Merge common code between PowerPC and Microblaze. This patch
splits the arch-specific stuff out into a new function,
early_init_dt_scan_chosen_arch().
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When swapping a new table into place, retain the old table until
its replacement is in place.
An old check for an empty table is removed because this is enforced
in populate_table().
__unbind() becomes redundant when followed by __bind().
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Add the flag DM_QUERY_INACTIVE_TABLE_FLAG to the ioctls to return
infomation about the loaded-but-not-yet-active table instead of the live
table. Prior to this patch it was impossible to obtain this information
until the device had been 'resumed'.
Userspace dmsetup and libdevmapper support the flag as of version 1.02.40.
e.g. dmsetup info --inactive vg1-lv1
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move bio completion out of dm_rh_mark_nosync in preparation for the
next patch.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Introduce a callback pointer from the log to dm-raid1 layer.
Before some region is set as "in-sync", we need to flush hardware cache on
all the disks. But the log module doesn't have access to the mirror_set
structure. So it will use this callback.
So far the callback is unused, it will be used in further patches.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This build warning:
kernel/sched.c: In function 'set_task_cpu':
kernel/sched.c:2070: warning: unused variable 'old_rq'
Made me realize that the forced2_migrations stat looks pretty
pointless (and a misnomer) - remove it.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'xen/fbdev' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
xen pvfb: Inhibit VM_IO flag to be set on vmalloc-ed framebuffers.
fb-defio: Inhibit VM_IO flag to be set on vmalloc-ed framebuffers.
fb-defio: If FBINFO_VIRTFB is defined, do not set VM_IO flag.
Fix toogle whether xenbus driver should be built as module or part of kernel.
Based on patch originally by Jeff Mahoney <jeffm@suse.com>
enclosure_status is expected to be a NULL terminated array of strings
but isn't actually NULL terminated. When writing an invalid value to
/sys/class/enclosure/.../.../status, it goes off the end of the array
and Oopses.
Fix by making the assumption true and adding NULL at the end.
Reported-by: Artur Wojcik <artur.wojcik@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
So far the maximum quota space limit was 4TB. Apparently this isn't enough
for Lustre guys anymore. So implement new quota format which raises block
limits to 2^64 bytes. Also store number of inodes and inode limits in
64-bit variables as 2^32 files isn't that insanely high anymore.
The first version of the patch has been developed by Andrew Perepechko
<Andrew.Perepechko@Sun.COM>.
CC: Andrew.Perepechko@Sun.COM
Signed-off-by: Jan Kara <jack@suse.cz>
Move definition of this constant to linux/quota.h so that it
cannot clash with other format IDs.
CC: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Make messages produced by ext3 more unified. It should be
easy to parse.
dmesg before patch:
[ 4893.684892] reservations ON
[ 4893.684896] xip option not supported
[ 4893.684964] EXT3-fs warning: maximal mount count reached, running
e2fsck is recommended
dmesg after patch:
[ 873.300792] EXT3-fs (loop0): using internal journaln
[ 873.300796] EXT3-fs (loop0): mounted filesystem with writeback data mode
[ 924.163657] EXT3-fs (loop0): error: can't find ext3 filesystem on dev loop0.
[ 723.755642] EXT3-fs (loop0): error: bad blocksize 8192
[ 357.874687] EXT3-fs (loop0): error: no journal found. mounting ext3 over ext2?
[ 873.300764] EXT3-fs (loop0): warning: maximal mount count reached, running e2fsck is recommended
[ 924.163657] EXT3-fs (loop0): error: can't find ext3 filesystem on dev loop0.
Signed-off-by: Alexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: Jan Kara <jack@suse.cz>
It is somewhat dangerous to use a straight enum here, because this will
reassign values of later variables if one of the earlier ones is removed.
Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Andreas Dilger <adilger@sun.com>
Signed-off-by: Jan Kara <jack@suse.cz>
All callers really want the more logical filemap_fdatawait_range interface,
so convert them to use it and merge wait_on_page_writeback_range into
filemap_fdatawait_range.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
There is no reason to make timer_stats_hrtimer_set_start_info and
friends visible to the rest of the kernel. So move all of them to
hrtimer.c. Also make timer_stats_hrtimer_set_start_info a static
inline function so it gets inlined and we avoid another function call.
Based on a patch by Thomas Gleixner.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
LKML-Reference: <20091210095629.GC4144@osiris.boeblingen.de.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The hrtimer_interrupt hang logic adjusts min_delta_ns based on the
execution time of the hrtimer callbacks.
This is error-prone for virtual machines, where a guest vcpu can be
scheduled out during the execution of the callbacks (and the callbacks
themselves can do operations that translate to blocking operations in
the hypervisor), which in can lead to large min_delta_ns rendering the
system unusable.
Replace the current heuristics with something more reliable. Allow the
interrupt code to try 3 times to catch up with the lost time. If that
fails use the total time spent in the interrupt handler to defer the
next timer interrupt so the system can catch up with other things
which got delayed. Limit that deferment to 100ms.
The retry events and the maximum time spent in the interrupt handler
are recorded and exposed via /proc/timer_list
Inspired by a patch from Marcelo.
Reported-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: kvm@vger.kernel.org
The core ftrace code (trace_clock_local) calls sched_clock()
directly, so we don't want to recurisvely trigger the ftrace
code. Rather than update every sched_clock() definition, tag
the prototype for everyone as notrace.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1260407223-10900-1-git-send-email-vapier@gentoo.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (51 commits)
Input: appletouch - give up maintainership
Input: dm355evm_kbd - switch to using sparse keymap library
Input: wistron_btns - switch to using sparse keymap library
Input: add generic support for sparse keymaps
Input: fix memory leak in force feedback core
Input: wistron - remove identification strings from DMI table
Input: psmouse - remove identification strings from DMI tables
Input: atkbd - remove identification strings from DMI table
Input: i8042 - remove identification strings from DMI tables
DMI: allow omitting ident strings in DMI tables
Input: psmouse - do not carry DMI data around
Input: matrix-keypad - switch to using dev_pm_ops
Input: keyboard - fix lack of locking when traversing handler->h_list
Input: gpio_keys - scan gpio state at probe and resume time
Input: keyboard - add locking around event handling
Input: usbtouchscreen - add support for ET&T TC5UH touchscreen controller
Input: xpad - add two new Xbox 360 devices
Input: polled device - do not start polling if interval is zero
Input: polled device - schedule first poll immediately
Input: add S3C24XX touchscreen driver
...
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (345 commits)
V4L/DVB (13542): ir-keytable: Allow dynamic table change
V4L/DVB (13541): atbm8830: replace 64-bit division and floating point usage
V4L/DVB (13540): ir-common: Cleanup get key evdev code
V4L/DVB (13539): ir-common: add __func__ for debug messages
V4L/DVB (13538): ir-common: Use a dynamic keycode table
V4L/DVB (13537): ir: Prepare the code for dynamic keycode table allocation
V4L/DVB (13536): em28xx: Use the full RC5 code on HVR-950 Remote Controller
V4L/DVB (13535): ir-common: Add a hauppauge new table with the complete RC5 code
V4L/DVB (13534): ir-common: Remove some unused fields/structs
V4L/DVB (13533): ir: use dynamic tables, instead of static ones
V4L/DVB (13532): ir-common: Add infrastructure to use a dynamic keycode table
V4L/DVB (13531): ir-common: rename the debug routine to allow exporting it
V4L/DVB (13458): go7007: subdev conversion
V4L/DVB (13457): s2250: subdev conversion
V4L/DVB (13456): s2250: Change module structure
V4L/DVB (13528): em28xx: add support for em2800 VC211A card
em28xx: don't reduce scale to half size for em2800
em28xx: don't load audio modules when AC97 is mis-detected
em28xx: em2800 chips support max width of 640
V4L/DVB (13523): dvb-bt8xx: fix compile warning
...
Fix up trivial conflicts due to spelling fixes from the trivial tree in
Documentation/video4linux/gspca.txt
drivers/media/video/cx18/cx18-mailbox.h
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-next-2.6:
sl82c105: remove no longer needed debugging code
sis5513: remove stale TODO
pdc202xx_old: remove no longer needed debugging code
cy82c693: remove no longer needed debugging code
cmd64x: remove no longer needed debugging code
alim15x3: remove obsolete and dangerous wdc_udma parameter
ide: Increase WAIT_DRQ to accomodate some CF cards and SSD drives.
cs5535: add pci id for AMD based CS5535 controllers
slc90e66: fix UDMA handling
drivers/ide/tx4938ide.c: use resource_size()
drivers/ide/ide_platform.c: use resource_size()
drivers/ide/au1xxx-ide.c: use resource_size()
hpt366: remove dead old timing tables
ide: update Kconfig text to mark as deprecated
ide-tape: remove the BKL
hpt366: kill unused #define's
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: add multi-input quirk for NextWindow Touchscreen.
HID: add support for Acan FG-8100 barcode reader
HID: make Media key on Logitech DiNovo Mini work
HID: support Logitech/3DConnexion SpaceTraveler and SpaceNavigator
HID: remove BKL from hiddev_ioctl_usage()
HID: fixup quirk for NCR devices
HID: pidff - fix unnecessary loop iterations on reset
HID: add NOGET quirk for another device from CH Products
HID: remove useless DRIVER_VERSION macro
HID: fix MODULE_AUTHOR usage in HID modules
HID: blacklist Acer Ferrari 4005 optical mouse
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (222 commits)
[SCSI] zfcp: Remove flag ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP
[SCSI] zfcp: Activate fc4s attributes for zfcp in FC transport class
[SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED
[SCSI] zfcp: Update FSF error reporting
[SCSI] zfcp: Improve ELS ADISC handling
[SCSI] zfcp: Simplify handling of ct and els requests
[SCSI] zfcp: Remove ZFCP_DID_MASK
[SCSI] zfcp: Move WKA port to zfcp FC code
[SCSI] zfcp: Use common code definitions for FC CT structs
[SCSI] zfcp: Use common code definitions for FC ELS structs
[SCSI] zfcp: Update FCP protocol related code
[SCSI] zfcp: Dont fail SCSI commands when transitioning to blocked fc_rport
[SCSI] zfcp: Assign scheduled work to driver queue
[SCSI] zfcp: Remove STATUS_COMMON_REMOVE flag as it is not required anymore
[SCSI] zfcp: Implement module unloading
[SCSI] zfcp: Merge trace code for fsf requests in one function
[SCSI] zfcp: Access ports and units with container_of in sysfs code
[SCSI] zfcp: Remove suspend callback
[SCSI] zfcp: Remove global config_mutex
[SCSI] zfcp: Replace local reference counting with common kref
...
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (137 commits)
sh: include empty zero page in romImage
sh: Make associative cache writes fatal on all SH-4A parts.
sh: Drop associative writes for SH-4 cache flushes.
sh: Partial revert of copy/clear_user_highpage() optimizations.
sh: Add default uImage rule for se7724, ap325rxa, and migor.
sh: allow runtime pm without suspend/resume callbacks
sh: mach-ecovec24: Remove un-defined settings for VPU
sh: mach-ecovec24: LCDC drive ability become high
sh: fix sh7724 VEU3F resource size
serial: sh-sci: Fix too early port disabling.
sh: pfc: pr_info() -> pr_debug() cleanups.
sh: pfc: Convert from ctrl_xxx() to __raw_xxx() I/O routines.
sh: Improve kfr2r09 serial port setup code
sh: Break out SuperH PFC code
sh: Move KEYSC header file
sh: convert /proc/cpu/aligmnent, /proc/cpu/kernel_alignment to seq_file
sh: Add CPG save/restore code for sh7724 R-standby
sh: Add SDHI power control support to Ecovec
mfd: Add power control platform data to SDHI driver
sh: mach-ecovec24: modify address map
...
acpi_check_resource_conflict() doesn't change the resource
it operates on, so the res parameter can be marked const.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Len Brown <len.brown@intel.com>
The trace_seq buffer might fill up, and right now one needs to check the
return value of each printf into the buffer to check for that.
Instead, have the buffer keep track of whether it is full or not, and
reject more input if it is full or would have overflowed with an input
that wasn't added.
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If the seq_read fills the buffer it will call s_start again on the next
itertation with the same position. This causes a problem with the
function_graph tracer because it consumes the iteration in order to
determine leaf functions.
What happens is that the iterator stores the entry, and the function
graph plugin will look at the next entry. If that next entry is a return
of the same function and task, then the function is a leaf and the
function_graph plugin calls ring_buffer_read which moves the ring buffer
iterator forward (the trace iterator still points to the function start
entry).
The copying of the trace_seq to the seq_file buffer will fail if the
seq_file buffer is full. The seq_read will not show this entry.
The next read by userspace will cause seq_read to again call s_start
which will reuse the trace iterator entry (the function start entry).
But the function return entry was already consumed. The function graph
plugin will think that this entry is a nested function and not a leaf.
To solve this, the trace code now checks the return status of the
seq_printf (trace_print_seq). If the writing to the seq_file buffer
fails, we set a flag in the iterator (leftover) and we do not reset
the trace_seq buffer. On the next call to s_start, we check the leftover
flag, and if it is set, we just reuse the trace_seq buffer and do not
call into the plugin print functions.
Before this patch:
2) | fput() {
2) | __fput() {
2) 0.550 us | inotify_inode_queue_event();
2) | __fsnotify_parent() {
2) 0.540 us | inotify_dentry_parent_queue_event();
After the patch:
2) | fput() {
2) | __fput() {
2) 0.550 us | inotify_inode_queue_event();
2) 0.548 us | __fsnotify_parent();
2) 0.540 us | inotify_dentry_parent_queue_event();
[
Updated the patch to fix a missing return 0 from the trace_print_seq()
stub when CONFIG_TRACING is disabled.
Reported-by: Ingo Molnar <mingo@elte.hu>
]
Reported-by: Jiri Olsa <jolsa@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing: (31 commits)
kill-the-bkl/reiserfs: turn GFP_ATOMIC flag to GFP_NOFS in reiserfs_get_block()
kill-the-bkl/reiserfs: drop the fs race watchdog from _get_block_create_0()
kill-the-bkl/reiserfs: definitely drop the bkl from reiserfs_ioctl()
kill-the-bkl/reiserfs: always lock the ioctl path
kill-the-bkl/reiserfs: fix reiserfs lock to cpu_add_remove_lock dependency
kill-the-bkl/reiserfs: Fix induced mm->mmap_sem to sysfs_mutex dependency
kill-the-bkl/reiserfs: panic in case of lock imbalance
kill-the-bkl/reiserfs: fix recursive reiserfs write lock in reiserfs_commit_write()
kill-the-bkl/reiserfs: fix recursive reiserfs lock in reiserfs_mkdir()
kill-the-bkl/reiserfs: fix "reiserfs lock" / "inode mutex" lock inversion dependency
kill-the-bkl/reiserfs: move the concurrent tree accesses checks per superblock
kill-the-bkl/reiserfs: acquire the inode mutex safely
kill-the-bkl/reiserfs: unlock only when needed in search_by_key
kill-the-bkl/reiserfs: use mutex_lock in reiserfs_mutex_lock_safe
kill-the-bkl/reiserfs: factorize the locking in reiserfs_write_end()
kill-the-bkl/reiserfs: reduce number of contentions in search_by_key()
kill-the-bkl/reiserfs: don't hold the write recursively in reiserfs_lookup()
kill-the-bkl/reiserfs: lock only once on reiserfs_get_block()
kill-the-bkl/reiserfs: conditionaly release the write lock on fs_changed()
kill-the-BKL/reiserfs: add reiserfs_cond_resched()
...
Split arch/arm/plat-omap/include/mach/omapfb.h into two files:
include/linux/omapfb.h - ioctls etc for userspace and some kernel
stuff for board files
drivers/video/omap/omapfb.h - for omapfb internal use
This cleans up omapfb.h and also makes it easier for the upcoming new
DSS driver to co-exist with the old driver.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
As scaling now takes place on all kind of cpu add/remove events a user
that configures values via proc should be able to configure if his set
values are still rescaled or kept whatever happens.
As the comments state that log2 was just a second guess that worked the
interface is not just designed for on/off, but to choose a scaling type.
Currently this allows none, log and linear, but more important it allwos
us to keep the interface even if someone has an even better idea how to
scale the values.
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1259579808-11357-3-git-send-email-ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
WAKEUP_RUNNING was an experiment, not sure why that ever ended up being
merged...
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently we try to do task placement in wake_up_new_task() after we do
the load-balance pass in sched_fork(). This yields complicated semantics
in that we have to deal with tasks on different RQs and the
set_task_cpu() calls in copy_process() and sched_fork()
Rename ->task_new() to ->task_fork() and call it from sched_fork()
before the balancing, this gives the policy a clear point to place the
task.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since we've had a much saner debugfs interface to this, remove the
sysctl one.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
[ v2: build fix ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
