The generic semaphore rewrite had a huge performance regression on AIM7
(and potentially other BKL-heavy benchmarks) because the generic
semaphores had been rewritten to be simple to understand and fair. The
latter, in particular, turns a semaphore-based BKL implementation into a
mess of scheduling.
The attempt to fix the performance regression failed miserably (see the
previous commit 00b41ec2611dc98f87f30753ee00a53db648d662 'Revert
"semaphore: fix"'), and so for now the simple and sane approach is to
instead just go back to the old spinlock-based BKL implementation that
never had any issues like this.
This patch also has the advantage of being reported to fix the
regression completely according to Yanmin Zhang, unlike the semaphore
hack which still left a couple percentage point regression.
As a spinlock, the BKL obviously has the potential to be a latency
issue, but it's not really any different from any other spinlock in that
respect. We do want to get rid of the BKL asap, but that has been the
plan for several years.
These days, the biggest users are in the tty layer (open/release in
particular) and Alan holds out some hope:
"tty release is probably a few months away from getting cured - I'm
afraid it will almost certainly be the very last user of the BKL in
tty to get fixed as it depends on everything else being sanely locked."
so while we're not there yet, we do have a plan of action.
Tested-by: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Alexander Viro <viro@ftp.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6: (21 commits)
Blackfin Serial Driver: abstract away DLAB differences into header
Blackfin Serial Driver: macro away the IER differences between processors
[Blackfin] arch: remove useless IRQ_SW_INT defines
[Blackfin] arch: protect linux/usb/musb.h include until the driver gets mainlined
[Blackfin] arch: protect linux/usb/isp1362.h include until the driver gets mainlined
[Blackfin] arch: add EBIU supporting for BF54x EZKIT SMSC LAN911x/LAN921x families embedded ethernet driver
[Blackfin] arch: Set spi flash partition on bf527 as like bf548.
[Blackfin] arch: fix bug - Remove module will not free L1 memory used
[Blackfin] arch: fix wrong header name in comment
[Blackfin] arch: Fix BUG - spi flash on bf527 ezkit would fail at mount
[Blackfin] arch: add twi_lcd and twi_keypad i2c board info to bf527-ezkit
[Blackfin] arch: Add physmap partition for BF527-EZkit
[Blackfin] arch: fix gdb testing regression
[Blackfin] arch: disable single stepping when delivering a signal
[Blackfin] arch: Delete unused (copied from m68k) entries in asm-offsets.c.
[Blackfin] arch: In the double fault handler, set up the PT_RETI slot
[Blackfin] arch: Support for CPU_FREQ and NOHZ
[Blackfin] arch: Functional power management support: Add CPU and platform voltage scaling support
[Blackfin] arch: fix bug - breaking the atomic sections code.
[Blackfin] arch: Equalize include files: Add VR_CTL masks
...
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (37 commits)
SH: catch negative denormal_subf1() retval in denormal_add()
sh: Fix DMAC base address for SH7709S
sh: update smc91x platform data for se7206.
sh: Stub in cpu_to_node() and friends for NUMA build.
sh: intc register modify fix
sh: no high level trigger on some sh3 cpus
sh: clean up sh7710 and sh7720 intc tables
sh: add interrupt ack code to sh3
sh: unify external irq pin code for sh3
sh-sci: avoid writing to nonexistent registers
sh-sci: sh7722 lacks scsptr registers
sh-sci: improve sh7722 support
sh: reset hardware from early printk
sh: drain and wait for early printk
sh: use sci_out() for early printk
sh: add memory resources to /proc/iomem
sh: add kernel bss resource
sh: fix sh7705 interrupt vector typo
sh: update smc91x platform data for se7722
sh: update smc91x platform data for MigoR
...
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (23 commits)
[POWERPC] Remove leftover printk in isa-bridge.c
[POWERPC] Remove duplicate #include
[POWERPC] Initialize lockdep earlier
[POWERPC] Document when printk is useable
[POWERPC] Fix bogus paca->_current initialization
[POWERPC] Fix of_i2c include for module compilation
[POWERPC] Make default cputable entries reflect selected CPU family
[POWERPC] spufs: lockdep annotations for spufs_dir_close
[POWERPC] spufs: don't requeue victim contex in find_victim if it's not in spu_run
[POWERPC] 4xx: Fix PCI mem in sequoia DTS
[POWERPC] 4xx: Add endpoint support to 4xx PCIe driver
[POWERPC] 4xx: Fix problem with new TLB storage attibute fields on 440x6 core
[POWERPC] spufs: spu_create should send inotify IM_CREATE event
[POWERPC] spufs: handle faults while the context switch pending flag is set
[POWERPC] spufs: fix concurrent delivery of class 0 & 1 exceptions
[POWERPC] spufs: try to route SPU interrupts to local node
[POWERPC] spufs: set SPU_CONTEXT_SWITCH_PENDING before synchronising SPU irqs
[POWERPC] spufs: don't acquire state_mutex interruptible while performing callback
[POWERPC] spufs: update master runcntl with context lock held
[POWERPC] spufs: fix post-stopped update of MFC_CNTL register
...
m32r can use the generic sys_pipe implementation.
The current sys_pipe implementation on m32r only differes from the
generic one by passing a lot of additional unused registers to sys_pipe.
Reviewed and tested by Hirokazu Takata.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The cris implementation of sys_pipe only differs from the generic one
by taking the BKL before calling do_pipe which isn't not nessecary.
Just kill the cris implementation and use the generic one.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
'ix' is unsigned but denormal_subf1() may return a negative int.
Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This printk() appears twice in the same function. Only the latter one
in the inval_range: section appears to be legitimate.
Signed-off-by: Nate Case <ncase@xes-inc.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Remove duplicate #include of <asm/prom.h> in
arch/powerpc/kernel/btext.c.
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This moves lockdep_init() to before udbg_early_init() as the later
can call things that acquire spinlocks etc... This also makes printk
safer to use earlier.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When debugging early boot problems, it's common to sprinkle printk's
all over the place. However, on 64-bit powerpc, this can lead to
memory corruption if done too early due to the PACA pointer and
lockdep core not being initialized.
This adds some comments to early_setup() that document when it is
safe to do so in order to save time for whoever has to debug that
stuff next.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When doing lockdep, I had two patches to initialize paca->_current
early, one bogus, and one correct. Unfortunately both got merged
as the bad one ended up being part of the main lockdep patch by
mistake. This causes memory corruption at boot. This removes
the offending code.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Changes the cputable so that various CPU families that have an exclusive
CONFIG_ option have a more sensible default entry to use if the specific
processor hasn't been identified.
This makes the kernel more generally useful when booted on an unknown
PVR for things like new 4xx variants.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (32 commits)
net: Added ASSERT_RTNL() to dev_open() and dev_close().
can: Fix can_send() handling on dev_queue_xmit() failures
netns: Fix arbitrary net_device-s corruptions on net_ns stop.
netfilter: Kconfig: default DCCP/SCTP conntrack support to the protocol config values
netfilter: nf_conntrack_sip: restrict RTP expect flushing on error to last request
macvlan: Fix memleak on device removal/crash on module removal
net/ipv4: correct RFC 1122 section reference in comment
tcp FRTO: SACK variant is errorneously used with NewReno
e1000e: don't return half-read eeprom on error
ucc_geth: Don't use RX clock as TX clock.
cxgb3: Use CAP_SYS_RAWIO for firmware
pcnet32: delete non NAPI code from driver.
fs_enet: Fix a memory leak in fs_enet_mdio_probe
[netdrvr] eexpress: IPv6 fails - multicast problems
3c59x: use netstats in net_device structure
3c980-TX needs EXTRA_PREAMBLE
fix warning in drivers/net/appletalk/cops.c
e1000e: Add support for BM PHYs on ICH9
uli526x: fix endianness issues in the setup frame
uli526x: initialize the hardware prior to requesting interrupts
...
This reverts commit 9f8daccaa05c14e5643bdd4faf5aed9cc8e6f11e, which was
reported to break X startup (xf86-video-ati-6.8.0). See
http://bugs.freedesktop.org/show_bug.cgi?id=15523
for details.
Reported-by: Laurence Withers <l@lwithers.me.uk>
Cc: Gary Hade <garyhade@us.ibm.com>
Cc: Greg KH <greg@kroah.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remember to close the files if copy_to_user() failed.
Spotted by dm.n9107@gmail.com.
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Cc: DM <dm.n9107@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
'put_char' of 'struct tty_operations' has changed from 'void' into 'int'.
This can also shut up compiler warnings.
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need to acquire the parent i_mutex with I_MUTEX_PARENT to keep
lockdep happy.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
We should not requeue the victim context in find_victim if the owner is
not in spu_run. It's first not needed because leaving the context on
the spu is an optimization and second is harmful because it means the
owner could re-enter spu_run when the context is on the runqueue and
trip the BUG_ON in __spu_update_sched_info.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
The processor models sh7706, sh7707 and sh7709 don't support high
level trigger sense configuration. And the intc code looks like
crap these days so what's the difference.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Clean up the intc tables by removing unneeded #ifdefs. The vector
list is what selects which interrupt sources that should be added,
having unsupported bitfields listed is ok as long as the vector
is excluded from the list.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch adds interrupt acknowledge code for external interrupt
sources on sh3 processors. Only really required for edge triggered
interrupts, but we ack regardless of sense configuration.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch unifies the sh3 external irq pin code. It buys us some
savings with reduced code redundancy, but the main feature with
this change is irq sense selection support for all sh3 processors.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Reset the transmitter and receiver when setting up early printk.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Drain by waiting for all characters to be sent, and make sure to
wait a little bit after setting up the baud rate.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Use sci_out() instead of ctrl_outw() for early printk setup code.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Add physical memory resources such as System RAM, Kernel code/data/bss
and reserved crash dump area to /proc/iomem. Same strategy as on x86.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Do like everyone else and have a struct resource for kernel bss.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Select smc91x bus width using platform data for se7722 now when the
smc91x header file is in place.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Select smc91x bus width and irg flags using platform data for MigoR
now when the smc91x header file is in place.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
SH_MPC1211 has been marked as BROKEN for some time.
Unless someone is working on reviving it now, I'd therefore suggest this
patch to remove it.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
