I'd like to use printk_ratelimit() in NMI context, but it's not
robust right now due to spinlock usage in lib/ratelimit.c. If an
NMI is unlucky enough to hit just that spot we might lock up trying
to take the spinlock again.
Fix that by using a trylock variant. If we contend on that lock we
can genuinely skip the message because the state is just being
accessed by another CPU (or by this CPU).
( We could use atomics for the suppressed messages field, but
i doubt it matters in practice and it makes the code heavier. )
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
I'd like to use printk_ratelimit() in atomic context, but that's
not possible right now due to the spinlock usage this commit
introduced more than a year ago:
717115e: printk ratelimiting rewrite
As a first step push the lock into the ratelimit state structure.
This allows us to deal with locking failures to be considered as an
event related to that state being too busy.
Also clean up the code a bit (without changing functionality):
- tidy up the definitions
- clean up the code flow
This also shrinks the code a tiny bit:
text data bss dec hex filename
264 0 4 268 10c ratelimit.o.before
255 0 0 255 ff ratelimit.o.after
( Whole-kernel data size got a bit larger, because we have
two ratelimit-state data structures right now. )
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: Fix whitespace inconsistencies
rcu: Fix thinko, actually initialize full tree
rcu: Apply results of code inspection of kernel/rcutree_plugin.h
rcu: Add WARN_ON_ONCE() consistency checks covering state transitions
rcu: Fix synchronize_rcu() for TREE_PREEMPT_RCU
rcu: Simplify rcu_read_unlock_special() quiescent-state accounting
rcu: Add debug checks to TREE_PREEMPT_RCU for premature grace periods
rcu: Kconfig help needs to say that TREE_PREEMPT_RCU scales down
rcutorture: Occasionally delay readers enough to make RCU force_quiescent_state
rcu: Initialize multi-level RCU grace periods holding locks
rcu: Need to update rnp->gpnum if preemptable RCU is to be reliable
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf_counter, powerpc, sparc: Fix compilation after perf_counter_overflow() change
perf_counter: x86: Fix PMU resource leak
perf util: SVG performance improvements
perf util: Make the timechart SVG width dynamic
perf timechart: Show the duration of scheduler delays in the SVG
perf timechart: Show the name of the waker/wakee in timechart
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Simplify sys_sched_rr_get_interval() system call
sched: Fix potential NULL derference of doms_cur
sched: Fix raciness in runqueue_is_locked()
sched: Re-add lost cpu_allowed check to sched_fair.c::select_task_rq_fair()
sched: Remove unneeded indentation in sched_fair.c::place_entity()
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Print the hypervisor returned tsc_khz during boot
x86: Correct segment permission flags in 64-bit linker script
x86: cpuinit-annotate SMP boot trampolines properly
x86: Increase timeout for EHCI debug port reset completion in early printk
x86: Fix uaccess_32.h typo
x86: Trivial whitespace cleanups
x86, apic: Fix missed handling of discrete apics
x86/i386: Remove duplicated #include
x86, mtrr: Convert loop to a while based construct, avoid naked semicolon
Revert 'x86: Fix system crash when loading with "reservetop" parameter'
x86, mce: Fix compile warning in case of CONFIG_SMP=n
x86, apic: Use logical flat on intel with <= 8 logical cpus
x86: SGI UV: Map MMIO-High memory range
x86: SGI UV: Add volatile semantics to macros that access chipset registers
x86: SGI UV: Fix IPI macros
x86: apic: Convert BUG() to BUG_ON()
x86: Remove final bits of CONFIG_X86_OLD_MCE
* 'writeback' of git://git.kernel.dk/linux-2.6-block:
nfs: initialize the backing_dev_info when creating the server
writeback: make balance_dirty_pages() gradually back more off
writeback: don't use schedule_timeout() without setting runstate
nfs: nfs_kill_super() should call bdi_unregister() after killing super
* 'linux-next' of git://git.infradead.org/ubi-2.6:
UBI: improve NOR flash erasure quirk
UBI: introduce flash dump helper
UBI: eliminate possible undefined behaviour
UBI: print a warning if too many PEBs are corrupted
UBI: amend NOR flash pre-erase quirk
UBI: print a message if ECH is corrupted and VIDH is ok
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (133 commits)
drm/vgaarb: add VGA arbitration support to the drm and kms.
drm/radeon: some r420s have a CP race with the DMA engine.
drm/radeon/r600/kms: rv670 is not DCE3
drm/radeon/kms: r420 idle after programming GA_ENHANCE
drm/radeon/kms: more fixes to rv770 suspend/resume path.
drm/radeon/kms: more alignment for rv770.c with r600.c
drm/radeon/kms: rv770 blit init called too late.
drm/radeon/kms: move around new init path code to avoid posting at init
drm/radeon/r600: fix some issues with suspend/resume.
drm/radeon/kms: disable VGA rendering engine before taking over VRAM
drm/radeon/kms: Move radeon_get_clock_info() call out of radeon_clocks_init().
drm/radeon/kms: add initial connector properties
drm/radeon/kms: Use surfaces for scanout / cursor byte swapping on big endian.
drm/radeon/kms: don't fail if we fail to init GPU acceleration
drm/r600/kms: fixup number of loops per blit calculation.
drm/radeon/kms: reprogram format in set base.
drm/radeon: avivo chips have no separate int bit for display
drm/radeon/r600: don't do interrupts
drm: fix _DRM_GEM addmap error message
drm: update crtc x/y when only fb changes
...
Fixed up trivial conflicts in firmware/Makefile due to network driver
(cxgb3) and drm (mga/r128/radeon) firmware being listed next to each
other.
The build of the dabusb driver broke:
drivers/media/video/dabusb.c:758: error: unknown field 'nodename' specified in initializer
drivers/media/video/dabusb.c:758: warning: initialization from incompatible pointer type
make[3]: *** wait: No child processes. Stop.
Due to this commit:
e454cea: Driver-Core: extend devnode callbacks to provide permissions
Missing the dabusb driver's dabusb_nodename() callback.
Similar issues with the iio/industrialio driver in staging, pointed out
and patched by Jean Delvare.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Industrialio-parts-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NFS may free the server structure without ever having used the
bdi, so we either need to flag the bdi as being uninitialized or
initialize it up front. This does the latter.
This fixes a crash with mounting more than one NFS file system,
should people ever need that kind of obscure NFS functionality.
Tested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Currently it just sleeps for a very short time, just 1 jiffy. If
we keep looping in there, continually delay for a little longer
of up to 100msec in total. That was the old limit for congestion
wait.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Otherwise we could be attempting to flush data for a writeback
thread and bdi that have already disappeared.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Commit 5622f295 ("x86, perf_counter, bts: Optimize BTS overflow
handling") removed the regs field from struct perf_sample_data and
added a regs parameter to perf_counter_overflow(). This breaks the
build on powerpc (and Sparc) as reported by Sachin Sant:
arch/powerpc/kernel/perf_counter.c: In function 'record_and_restart':
arch/powerpc/kernel/perf_counter.c:1165: error: unknown field 'regs' specified in initializer
This adjusts arch/powerpc/kernel/perf_counter.c to correspond with the
new struct perf_sample_data and perf_counter_overflow().
[ v2: also fix Sparc, Markus Metzger <markus.t.metzger@intel.com> ]
Reported-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Markus Metzger <markus.t.metzger@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: benh@kernel.crashing.org
Cc: linuxppc-dev@ozlabs.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <19127.8400.376239.586120@drongo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
VGA arb requires DRM support for non-kms drivers, to turn on/off
irqs when disabling the mem/io regions.
VGA arb requires KMS support for GPUs where we can turn off VGA
decoding. Currently we know how to do this for intel and radeon
kms drivers, which allows them to be removed from the arbiter.
This patch comes from Fedora rawhide kernel.
Signed-off-by: Dave Airlie <airlied@redhat.com>
This patch makes sure the CP doesn't DMA do VRAM while 2D
is active by inserting a CP resync token.
todo: port to kms.
Signed-off-by: Dave Airlie <airlied@redhat.com>
This resumes my
RV730PRO (4650)
RV770 (4850)
fine.
Still researching the RV4550 (RV710), resumes without X fine.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Ingo Molnar
Linus Torvalds
Jens Axboe
Artem Bityutskiy
Peter Williams
Paul Mackerras
Dave Airlie
Alex Deucher
Dave Airlie