Impact: save on memory
Currently, a ring buffer was allocated for each "possible_cpus". On
some systems, this is the same as NR_CPUS. Thus, if a system defined
NR_CPUS = 64 but it only had 1 CPU, we could have possibly 63 useless
ring buffers taking up space. With a default buffer of 3 megs, this
could be quite drastic.
This patch changes the ring buffer code to only allocate ring buffers
for online CPUs. If a CPU goes off line, we do not free the buffer.
This is because the user may still have trace data in that buffer
that they would like to look at.
Perhaps in the future we could add code to delete a ring buffer if
the CPU is offline and the ring buffer becomes empty.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: fix to task live locking on reading trace_pipe on one CPU
The same code is used for both trace_pipe (all CPUS) and the per_cpu
trace_pipe file. When there is no data to read, it will check for
signals and wait on the trace wait queue.
The problem happens with the per_cpu wait. The trace_wait code checks
all CPUs. Thus, if there's data in another CPU buffer, then it will
exit the wait, without checking for signals or waiting on the wait queue.
It would then try to read the empty buffer, and since that will just
return nothing, then it will try to wait again. Unfortunately, that will
again fail due to there still being data in the other buffers. This
ends up with a live lock for the task.
This patch fixes the trace_wait to be aware that the iterator may only
be waiting on a single buffer.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
To save memory, the tracer ring buffers are set to a minimum.
The activating of a trace expands the ring buffer size. This patch
adds this expanding, when an event is activated.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: less memory impact on systems not using tracer
When the kernel boots up that has tracing configured, it allocates
the default size of the ring buffer. This currently happens to be
1.4Megs per possible CPU. This is quite a bit of wasted memory if
the system is never using the tracer.
The current solution is to keep the ring buffers to a minimum size
until the user uses them. Once a tracer is piped into the current_tracer
the ring buffer will be expanded to the default size. If the user
changes the size of the ring buffer, it will take the size given
by the user immediately.
If the user adds a "ftrace=" to the kernel command line, then the ring
buffers will be set to the default size on initialization.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
* 'for-linus' of git://oss.sgi.com/xfs/xfs:
xfs: only issues a cache flush on unmount if barriers are enabled
xfs: prevent lockdep false positive in xfs_iget_cache_miss
xfs: prevent kernel crash due to corrupted inode log format
Current VR5500 processor support lacks of some functions which are
expected to be configured/synthesized on arch initialization.
Here're some VR5500A spec notes:
* All execution hazards are handled in hardware.
* Once VR5500A stops the operation of the pipeline by WAIT instruction,
it could return from the standby mode only when either a reset, NMI
request, or all enabled interrupts is/are detected. In other words,
if interrupts are disabled by Status.IE=0, it keeps in standby mode
even when interrupts are internally asserted.
Notes on WAIT: The operation of the processor is undefined if WAIT
insn is in the branch delay slot. The operation is also undefined
if WAIT insn is executed when Status.EXL and Status.ERL are set to 1.
* VR5500A core only implements the Load prefetch.
With these changes, it boots fine.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
radeonfb/aty128fb: Disable broken early resume hook for PowerBooks
hvc_console: Remove tty->low_latency on pseries backends
powerpc: fix linkstation and storcenter compilation breakage
powerpc/4xx: Enable SERIAL_OF support by default for Virtex platforms
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel:
drm/i915: fix 945 fence register writes for fence 8 and above.
drm/i915: Protect active fences on i915
drm/i915: Check to see if we've pinned all available fences
drm/i915: Check fence status on every pin.
drm/i915: First recheck for an empty fence register.
drm/i915: Fix bad \n in MTRR failure notice.
drm/i915: Don't restore palettes through VGA registers.
i915: add newline to i915_gem_object_pin failure msg
drm: Return EINVAL on duplicate objects in execbuffer object list
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: work around Fedora-11 x86-32 kernel failures on Intel Atom CPUs
On swapon() path, it has already i_mutex. So, this uses i_alloc_sem
instead of it.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reported-by: Laurent GUERBY <laurent@guerby.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The last 8 fence registers sit at a different offset, so when we went to set
fence number 8 in the lower offset, we instead set PGETBL_CTL, and the GPU
got all sorts of angry at us.
fd.o bug #20567. Easily reproducible by running glxgears and killing it about
6 times.
Signed-off-by: Eric Anholt <eric@anholt.net>
The i915 also uses the fence registers for GPU access to tiled buffers so
we cannot reallocate one whilst it is on the active list. By performing a
LRU scan of the fenced buffers we also avoid waiting the possibility of
waiting on a pinned, or otherwise unusable, buffer.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
Impact: work around boot crash
Work around Intel Atom erratum AAH41 (probabilistically) - it's triggering
in the field.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Kyle McMartin <kyle@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix kpf_copy_bit(src,dst) to be kpf_copy_bit(dst,src) to match the
actual call patterns, e.g. kpf_copy_bit(kflags, KPF_LOCKED, PG_locked).
This misplacement of src/dst only affected reporting of PG_writeback,
PG_reclaim and PG_buddy. For others kflags==uflags so not affected.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need to check and report if there are no available fences - or else we
spin endlessly waiting for a buffer to magically unpin itself.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
As we may steal the fence register of an unpinned buffer for another,
every time we repin the buffer we need to recheck whether it needs to be
allocated a fence.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
If we wait upon a request and successfully unbind a buffer occupying a
fence register, then that slot will be freed and cause a NULL derefrence
upon rescanning.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
Comparing the layouts of struct detail_pixel_timing with
x.org's struct detailed_timings and how those are handled,
it appears that the hsync_positive and vsync_positive
fields are backwards.
This patch fixes https://bugs.freedesktop.org/show_bug.cgi?id=20019
for me. It was tested on 2 monitors, LG FLATRON L225WS 22" and
a YAKUMO 17" for which more details are unknown.
Signed-off-by: Pantelis Koukousoulas <pktoss@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
radeonfb and aty128fb have a special hook called by the PowerMac platform
code very very early on resume from sleep to bring the screen back. This
is useful for debugging wakup problems, but unfortunately, this also became
a source of problems of its own.
The hook is called extremely early, with interrupts still off, and the code
path involved with that code nowadays rely on things like taking mutexes,
GFP_KERNEL allocations, etc...
In addition, the driver now relies on the PCI core to restore the standard
config space before calling resume which doesn't happen with this early
code path.
I'm keeping the code in but commented out along with a fixup call to
pci_restore_state(). The reason is that I still want to make it easy to
re-enable temporarily to track wake up problems, and it's possible that
I can revive it at some stage if we make sleeping things save to call
in early resume using a system state.
In the meantime, this should fix several reported regressions.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The hvcs and hvsi backends both set tty->low_latency to one, along
with more or less scary comments regarding bugs or races that would
happen if not doing so.
However, they also both call tty_flip_buffer_push() in conexts where
it's illegal to do so since some recent tty changes (or at least it
may have been illegal always but it nows blows) when low_latency is
set (ie, hard interrupt or with spinlock held and irqs disabled).
This removes the setting for now to get them back to working condition,
we'll have to address the races described in the comments separately
if they are still an issue (some of this might have been fixed already).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Prevent the kernel from being crashed by a divide-by-zero operation when
supplied an incorrectly filled 'struct fb_var_screeninfo' from userland.
Previously i810_main.c:1005 (i810_check_params) was using the global
'yres' symbol previously defined at i810_main.c:145 as a module parameter
value holder (i810_main.c:2174). If i810fb is compiled-in or if this
param doesn't get a default value, this direct usage leads to a
divide-by-zero at i810_main.c:1005 (i810_check_params). The patch simply
replace the 'yres' global, perhaps undefined symbol usage by a given
parameter structure lookup.
This problem occurs with directfb, mplayer -vo fbdev, SDL library.
It was also reported ( but non solved ) at:
http://mail.directfb.org/pipermail/directfb-dev/2008-March/004050.html
Signed-off-by: Samuel CUELLA <samuel.cuella@supinfo.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There isn't any mcfqspi.h in the tree, and without it everything inside the
#ifdef CONFIG_SPI is uncompilable.
Signed-off-by: Steven King <sfking@fdwdc.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Update the RCU documentation to call out the need for callers of
primitives like call_rcu() and synchronize_rcu() to prevent subsequent RCU
readers from hazard.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We were returning early in the sysfs directory cleanup function if the
user belonged to a non init usernamespace. Due to this a lot of the
cleanup was not done and we were left with a leak. Fix the leak.
Reported-by: Serge Hallyn <serue@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Tested-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit e480814f13 ("[MTD] [MAPS] physmap:
fix wrong free and del_mtd_{partition,device}") introduces a NULL pointer
dereference in physmap_flash_remove when called from the error path in
physmap_flash_probe (if map_probe failed).
Call del_mtd_{partition,device} only if info->cmtd was not NULL.
Reported-by: pHilipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When GTT size is equal to amount of video memory, the amount of GTT
entries is computed lower than zero, which is invalid and leads to
off-by-one error in intel_i915_configure()
Originally posted here:
http://bugzilla.kernel.org/show_bug.cgi?id=12539http://bugzilla.redhat.com/show_bug.cgi?id=445592
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Cc: Lubomir Rintel <lkundrak@v3.sk>
Cc: Dave Airlie <airlied@linux.ie>
Reviewed-by: Eric Anholt <eric@anholt.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 771999b65f ("[MTD] DataFlash: bugfix,
binary page sizes now handled") broke support for probing AT45DB321C flash
chips. These chips do not support the "page size" status bit, so if we
match the JEDEC id return early.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Will Newton <will.newton@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a problem in the IDR system, where an idr_remove_all() hands a data
element to call_rcu() (via free_layer()) before making that data element
inaccessible to new readers. This is very bad, and results in readers
still having a reference to this data element at the end of the grace
period.
Tests on large machines that concurrently map and unmap user-space memory
within the same multithreaded process result in crashes within about five
minutes. Applying this patch increases the kernel's longevity to the
three-to-eight-hour range.
There appear to be other similar problems in idr_get_empty_slot() and
sub_remove(), but I fixed the easy one in idr_remove_all() first. It is
therefore no surprise that failures still occur.
Located-by: Milton Miller II <miltonm@austin.ibm.com>
Tested-by: Milton Miller II <miltonm@austin.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Very annoying when working with containters.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: fix bug to make agp work with dri
Jeffrey reported that dri does work with 64bit, but doesn't work with
32bit it turns out NB aperture is 32M, aperture on agp is 128M
64bit is using 64M for vaidation for 64 iommu/gart 32bit is only using
32M..., and will not update the nb aperture.
So try to compare nb apterture and agp apterture before leaving not
touch nb aperture.
Reported-by: Jeffrey Trull <jetrull@sbcglobal.net>
Tested-by: Jeffrey Trull <jetrull@sbcglobal.net>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Dave Airlie <airlied@linux.ie>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ->put_char changes
* HIGHMEM is bogus it seems, there is no kmap_atomic() et al
* some includes
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Chris Zankel <zankel@tensilica.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The adt7468 chip supports VRM10 sensors just like the adt7463; add a
missing check for it.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The verstep check in the lm85 driver fails because the upper nibble of
the version register is 0x7, not 0x6, on the adt7468 chip. Probing of
all adt7468s was broken by 69fc1feba2
("hwmon: (lm85) Rework the device detection"), and this patch fixes
that. Also add in a missing i2c_device_id that accidentally got dropped
from the original patch.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The COMPAT_BRK kconfig symbol does not depend on EMBEDDED, but it is in
the midst of the EMBEDDED menu symbols, so it mucks up the EMBEDDED menu.
Fix by moving it to just after all of the EMBEDDED menu symbols. Also,
ANON_INODES has a similar problem, so move it to just above the EMBEDDED
menu items since it is used in the EMBEDDED menu.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
get_nid_for_pfn() returns int
Presumably the (nid < 0) case has never happened.
We do know that it is happening on one system while creating a symlink for
a memory section so it should also happen on the same system if
unregister_mem_sect_under_nodes() were called to remove the same symlink.
The test was actually added in response to a problem with an earlier
version reported by Yasunori Goto where one or more of the leading pages
of a memory section on the 2nd node of one of his systems was
uninitialized because I believe they coincided with a memory hole.
That earlier version did not ignore uninitialized pages and determined
the nid by considering only the 1st page of each memory section. This
caused the symlink to the 1st memory section on the 2nd node to be
incorrectly created in /sys/devices/system/node/node0 instead of
/sys/devices/system/node/node1. The problem was fixed by adding the
test to skip over uninitialized pages.
I suspect we have not seen any reports of the non-removal
of a symlink due to the incorrect declaration of the nid
variable in unregister_mem_sect_under_nodes() because
- systems where a memory section could have an uninitialized
range of leading pages are probably rare.
- memory remove is probably not done very frequently on the
systems that are capable of demonstrating the problem.
- lingering symlink(s) that should have been removed may
have simply gone unnoticed.
[garyhade@us.ibm.com: wrote changelog]
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: prevent locking up by lockdep tracer
The lockdep tracer uses trace_vprintk and thus trace_vprintk can not
call back into lockdep without locking up.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
The VGA registers just hit the pipe registers that we already set through
MMIO. This fixes strange colors on resume.
Signed-off-by: Pierre Willenbrock <pierre@pirsoft.de>
Signed-off-by: Eric Anholt <eric@anholt.net>
If userspace passes an object list with the same object appearing more
than once, we end up hitting the BUG_ON() in
i915_gem_object_set_to_gpu_domain() as it gets called a second time
for the same object.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
