| Age | Commit message (Collapse) | Author |
|---|
|
In addition, add board support for the DM355 Evaluation Module (EVM)
and the DM355 Leopard board.
Original DM355 EVM support done by Sandeep Paulraj, with significant
updates and improvements by David Brownell. DM355 Leopord support
done by Koen Kooi.
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
Signed-off-by: Koen Kooi <koen@beagleboard.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
|
|
Signed-off-by: Hugo Villeneuve <hugo.villeneuve@lyrtech.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
|
|
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
|
|
Add support for Texas Instuments Common Platform Interrupt Controller
(cp_intc) used on DA830/OMAP-L137.
Signed-off-by: Steve Chen <schen@mvista.com>
Signed-off-by: Mark Greer <mgreer@mvista.com>
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
|
|
The davinci pre-kernel boot code assumes that all platforms use the
same UART base address for the console. That assumption is not longer
valid with some newer SoCs so determine the console UART base address
from the machine number passed in from bootloader.
Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
|
|
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
|
|
This patch defines debug macros for low-level debugging for Davinci
based platforms
Tested on :
- DM644x DaVinci EVM
- DM646X DaVinciHD EVM
- DM355 EVM
This patch attempts to solve the low-level debug issue in DM646x. The
UART on DM646x SoC allows only 32-bit access. The existing
debug-macro.S uses the macros from debug-8250.S file. This led to
garbage serial out in the case of DM646x.
The inclusion of debug-8250.S does not allow for run time fix for this
issue. There are compile time errors due to multiple definitions of
the macros. Also when building a single image for multiple DaVinci
Platforms, the ifdefs cannot be relied upon.
The solution below does not include the debug-8250.S file and defines
the necessary macros. This solution was arrived at after observing
that word access does not affect the low-level debug messages on
DM644x/DM355.
The other approach to this issue is to use the UART module information
available in the peripheral registers to decide the access
mechanism. But this will have to be done for every access of UART
specifically for DM646x. Also this calls for a modification of the
debug-8250.S file.
Signed-off-by: Chaithrika U S <chaithrika@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
|
|
This patch seems to get me much more reliable performance using the
GPIO banked interrupts on dm355 for the dm9000 driver.
Changes include:
- init GPIO handling along with normal GPIO init
- mask the level-sensitive bank IRQ during handling
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
|
|
Fix two IRQ triggering bugs affecting GPIO IRQs:
- Make sure enabling with IRQ_TYPE_NONE ("default, unspecified")
isn't a NOP ... default to both edges, at least one must work.
- As noted by Kevin Hilman, setting the irq trigger type for a
banked gpio interrupt shouldn't enable irqs that are disabled.
Since GPIO IRQs haven't been used much yet, it's not clear these
bugs could have affected anything. The few current users don't
seem to have been obviously suffering from these issues.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
|
|
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
MIPS: IP32: Remove unnecessary if not even harmful volatile keywords.
MIPS: IP32: Fix build error due to uninitialized variable.
MIPS: Fix sparse warning in incompatiable argument type of clear_user.
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/maple: Add a quirk to disable MSI for IPR on Bimini
|
|
They are unneeded and as the issue fixed in lmo commit
63f7ec59053e3f850ab67a9938e631bcba64c6ce shows even harmful.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
CC arch/mips/sgi-ip32/ip32-reset.o
cc1: warnings being treated as errors
arch/mips/sgi-ip32/ip32-reset.c: In function 'debounce':
arch/mips/sgi-ip32/ip32-reset.c:97: error: 'reg_a' is used uninitialized in this function
The issues is old but due to the volatile keyword gcc older than 4.4 did
not warn about this obvious bug.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
The type of the second argument of access_ok should be (void __user *).
The unnecessary conversion of the clear_user address argument was causing
sparse to emit warnings on the __chk_user_ptr check.
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
Something in the HW or FW setup is busted and MSIs aren't working with
IPR on Bimini, so until we figure out exaxtly what's up, we quirk them
out
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
|
|
This patch fixes the ap325rxa ncm03j camera code to handle
the case where no i2c driver is present. Without this fix
i2c_transfer() may be passed NULL as adapter which results
in a crash.
Triggered when i2c-sh_mobile.c failed to probe() due to
missing MSTP clocks.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
|
|
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
MIPS: 64-bit: Fix system lockup.
MIPS: IP28: Change to build with -mr10k-cache-barrier=store
MIPS: IP22: Fix hang in power button interrupt handler
MIPS: IP32: Fix hang on shutdown in power button interrupt handler.
|
|
* master.kernel.org:/home/rmk/linux-2.6-arm: (25 commits)
[ARM] 5519/1: amba probe: pass "struct amba_id *" instead of void *
[ARM] 5517/1: integrator: don't put clock lookups in __initdata
[ARM] 5518/1: versatile: don't put clock lookups in __initdata
[ARM] mach-l7200: fix spelling of SYS_CLOCK_OFF
[ARM] Double check memmap is actually valid with a memmap has unexpected holes V2
[ARM] realview: fix broadcast tick support
[ARM] realview: remove useless smp_cross_call_done()
[ARM] smp: fix cpumask usage in ARM SMP code
[ARM] 5513/1: Eurotech VIPER SBC: fix compilation error
[ARM] 5509/1: ep93xx: clkdev enable UARTS
ARM: OMAP2/3: Change omapfb to use clkdev for dispc and rfbi, v2
ARM: OMAP3: Fix HW SAVEANDRESTORE shift define
ARM: OMAP3: Fix number of GPIO lines for 34xx
[ARM] S3C: Do not set clk->owner field if unset
[ARM] S3C2410: mach-bast.c registering i2c data too early
[ARM] S3C24XX: Fix unused code warning in arch/arm/plat-s3c24xx/dma.c
[ARM] S3C64XX: fix GPIO debug
[ARM] S3C64XX: GPIO include cleanup
[ARM] nwfpe: fix 'floatx80_is_nan' sparse warning
[ARM] nwfpe: Add decleration for ExtendedCPDO
...
|
|
The address range size calculation inside local_flush_tlb_kernel_range()
is being truncated by a too small size variable holder on 64-bit systems.
The truncated size can result in an erroneous tlbsize check that means we
sit spinning inside a loop trying to flush a hige number of TLB entries.
This is for all intents and purposes a system hang. Fix by using an
appropriately sized valiable to hold the size.
[Ralf: Greg's original patch submission identified the issue and fixed one
instance in tlb-r4k.c but there there were several more. For consistency
I also modified tlb-r3k.c even though that file is only used on 32-bit.]
Signed-off-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
Richard Sandiford's new code for inserting the cache-barriers, for GCC
4.3 and above and already incorporated in the current GCC-release, uses
a slightly different option-syntax.
Signed-off-by: peter fuerst <post@pfrst.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
The hang was caused by the use of disable_irq() from the interrupt handler
itself. Fixed by the use of disable_irq_nosync(). The issue was
triggered by:
commit 3aa551c9b4c40018f0e261a178e3d25478dc04a9
Author: Thomas Gleixner <tglx@linutronix.de>
Date: Mon Mar 23 18:28:15 2009 +0100
genirq: add threaded interrupt handler support
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
The hang was caused by the use of disable_irq() from the interrupt handler
itself. Fixed by the use of disable_irq_nosync(). The issue was
triggered by:
commit 3aa551c9b4c40018f0e261a178e3d25478dc04a9
Author: Thomas Gleixner <tglx@linutronix.de>
Date: Mon Mar 23 18:28:15 2009 +0100
genirq: add threaded interrupt handler support
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
* 'fixes-for-linus' of git://git.monstr.eu/linux-2.6-microblaze:
microblaze: Fix kind-of-intr checking against number of interrupts
microblaze: Update Microblaze defconfig
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc: Explicit alignment for .data.cacheline_aligned
powerpc/ps3: Update ps3_defconfig
powerpc/ftrace: Fix constraint to be early clobber
powerpc/ftrace: Use pr_devel() in ftrace.c
powerpc: Do not assert pte_locked for hugepage PTE entries
|
|
Remove the __initdata annotation for the clock lookups, since they
will be needed when loading modules which use clk_get().
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Remove the __initdata annotation for the clock lookups, since they
will be needed when loading modules which use clk_get().
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Fix performance regression caused by paravirt_ops on native kernels
xen: use header for EXPORT_SYMBOL_GPL
x86, 32-bit: fix kernel_trap_sp()
x86: fix percpu_{to,from}_op()
x86: mtrr: Fix high_width computation when phys-addr is >= 44bit
x86: Fix false positive section mismatch warnings in the apic code
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: Append prompt in /debug/tracing/README file
x86/function-graph: fix constraint for recording old return value
|
|
+ Fix typographic fault.
Signed-off-by: Michal Simek <monstr@monstr.eu>
|
|
Signed-off-by: Michal Simek <monstr@monstr.eu>
|
|
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
holes V2
pfn_valid() is meant to be able to tell if a given PFN has valid memmap
associated with it or not. In FLATMEM, it is expected that holes always
have valid memmap as long as there is valid PFNs either side of the hole.
In SPARSEMEM, it is assumed that a valid section has a memmap for the
entire section.
However, ARM and maybe other embedded architectures in the future free
memmap backing holes to save memory on the assumption the memmap is never
used. The page_zone linkages are then broken even though pfn_valid()
returns true. A walker of the full memmap must then do this additional
check to ensure the memmap they are looking at is sane by making sure the
zone and PFN linkages are still valid. This is expensive, but walkers of
the full memmap are extremely rare.
This was caught before for FLATMEM and hacked around but it hits again for
SPARSEMEM because the page_zone linkages can look ok where the PFN linkages
are totally screwed. This looks like a hatchet job but the reality is that
any clean solution would end up consumning all the memory saved by punching
these unexpected holes in the memmap. For example, we tried marking the
memmap within the section invalid but the section size exceeds the size of
the hole in most cases so pfn_valid() starts returning false where valid
memmap exists. Shrinking the size of the section would increase memory
consumption offsetting the gains.
This patch identifies when an architecture is punching unexpected holes
in the memmap that the memory model cannot automatically detect and sets
ARCH_HAS_HOLES_MEMORYMODEL. At the moment, this is restricted to EP93xx
which is the model sub-architecture this has been reported on but may expand
later. When set, walkers of the full memmap must call memmap_valid_within()
for each PFN and passing in what it expects the page and zone to be for
that PFN. If it finds the linkages to be broken, it assumes the memmap is
invalid for that PFN.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
I don't think anything guarantees that the objects in data.page_aligned
are a multiple of PAGE_SIZE, thus the section may end on any boundary.
So the following section, .data.cacheline_aligned needs an explicit
alignment.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
|
|
Refresh and set these options:
CONFIG_SYSFS_DEPRECATED_V2: y -> n
CONFIG_INPUT_JOYSTICK: y -> n
CONFIG_HID_SONY: n -> m
CONFIG_RTC_DRV_PS3: - -> m
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
|
|
After upgrading my distcc boxes from gcc 4.2.2 to 4.4.0, the function
graph tracer broke. This was discovered on my x86 boxes.
The issue is that gcc used the same register for an output as it did for
an input in an asm statement. I first thought this was a bug in gcc and
reported it. I was notified that gcc was correct and that the output had
to be flagged as an "early clobber".
I noticed that powerpc had the same issue and this patch fixes it.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
|
|
pr_debug() can now result in code being generated even when #DEBUG
is not defined. That's not really desirable in the ftrace code
which we want to be snappy.
With CONFIG_DYNAMIC_DEBUG=y:
size before:
text data bss dec hex filename
3334 672 4 4010 faa arch/powerpc/kernel/ftrace.o
size after:
text data bss dec hex filename
2616 360 4 2980 ba4 arch/powerpc/kernel/ftrace.o
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
|
|
With CONFIG_DEBUG_VM, an assertion is made when changing the protection
flags of a PTE that the PTE is locked. Huge pages use a different pagetable
format and the assertion is bogus and will always trigger with a bug looking
something like
Unable to handle kernel paging request for data at address 0xf1a00235800006f8
Faulting instruction address: 0xc000000000034a80
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=32 NUMA Maple
Modules linked in: dm_snapshot dm_mirror dm_region_hash
dm_log dm_mod loop evdev ext3 jbd mbcache sg sd_mod ide_pci_generic
pata_amd ata_generic ipr libata tg3 libphy scsi_mod windfarm_pid
windfarm_smu_sat windfarm_max6690_sensor windfarm_lm75_sensor
windfarm_cpufreq_clamp windfarm_core i2c_powermac
NIP: c000000000034a80 LR: c000000000034b18 CTR: 0000000000000003
REGS: c000000003037600 TRAP: 0300 Not tainted (2.6.30-rc3-autokern1)
MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28002484 XER: 200fffff
DAR: f1a00235800006f8, DSISR: 0000000040010000
TASK = c0000002e54cc740[2960] 'map_high_trunca' THREAD: c000000003034000 CPU: 2
GPR00: 4000000000000000 c000000003037880 c000000000895d30 c0000002e5a2e500
GPR04: 00000000a0000000 c0000002edc40880 0000005700000393 0000000000000001
GPR08: f000000011ac0000 01a00235800006e8 00000000000000f5 f1a00235800006e8
GPR12: 0000000028000484 c0000000008dd780 0000000000001000 0000000000000000
GPR16: fffffffffffff000 0000000000000000 00000000a0000000 c000000003037a20
GPR20: c0000002e5f4ece8 0000000000001000 c0000002edc40880 0000000000000000
GPR24: c0000002e5f4ece8 0000000000000000 00000000a0000000 c0000002e5f4ece8
GPR28: 0000005700000393 c0000002e5a2e500 00000000a0000000 c000000003037880
NIP [c000000000034a80] .assert_pte_locked+0xa4/0xd0
LR [c000000000034b18] .ptep_set_access_flags+0x6c/0xb4
Call Trace:
[c000000003037880] [c000000003037990] 0xc000000003037990 (unreliable)
[c000000003037910] [c000000000034b18] .ptep_set_access_flags+0x6c/0xb4
[c0000000030379b0] [c00000000014bef8] .hugetlb_cow+0x124/0x674
[c000000003037b00] [c00000000014c930] .hugetlb_fault+0x4e8/0x6f8
[c000000003037c00] [c00000000013443c] .handle_mm_fault+0xac/0x828
[c000000003037cf0] [c0000000000340a8] .do_page_fault+0x39c/0x584
[c000000003037e30] [c0000000000057b0] handle_page_fault+0x20/0x5c
Instruction dump:
7d29582a 7d200074 7800d182 0b000000 3c004000 3960ffff 780007c6 796b00c4
7d290214 7929a302 1d290068 7d6b4a14 <800b0010> 7c000074 7800d182 0b000000
This patch fixes the problem by not asseting the PTE is locked for VMAs
backed by huge pages.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
|
|
|
|
Having discussed broadcast tick support with Thomas Glexiner, the
broadcast tick devices should be registered with a higher rating
than the global tick device, and it should have the ONESHOT and
PERIODIC feature flags set.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Thomas Glexiner <tglx@linutronix.de>
|
|
smp_cross_call_done() is a no-op for MPCore, and since it's only
used by platform code, there's no point in having it unless it's
doing something.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
The ARM SMP code wasn't properly updated for the cpumask changes, which
results in smp_timer_broadcast() broadcasting ticks to non-online CPUs.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Compilation for this board yields the following errors:
arch/arm/mach-pxa/viper.c:511: error: 'FFUART' undeclared here (not in a function)
arch/arm/mach-pxa/viper.c:520: error: 'BTUART' undeclared here (not in a function)
arch/arm/mach-pxa/viper.c:529: error: 'STUART' undeclared here (not in a function)
Fix them by including the necessary header.
Signed-off-by: Ricardo Martins <rasm@fe.up.pt>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
Fix the clkdev API support for the ep93xx uart clocks.
The uarts available in the ep93xx have individual clock controls.
The current implementation assumes that the bootloader has enabled
the clocks before the kernel has booted. It also assumes that the
bootloader has set the UARTBAUD bit indicating that the uarts are
running off the 14.7456MHz external crystal.
This fixes both issues. It also allows the uart clocks to be stopped
when there are no users.
Tested-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Cc: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6
|
|
|
|
This makes the framebuffer work on omap3.
Also fix the clk_get usage for checkpatch.pl
"ERROR: do not use assignment in if condition".
Cc: Imre Deak <imre.deak@nokia.com>
Cc: linux-fbdev-devel@lists.sourceforge.net
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Tony Lindgren <tony@atomide.com>
|
|
The OMAP3430ES2_SAVEANDRESTORE_SHIFT macro is used
by powerdomain code in
"1 << OMAP3430ES2_SAVEANDRESTORE_SHIFT" manner, but
the definition was also (1 << 4), meaning we actually
modified bit 16. So the definition needs to be 4.
This fixes also a cold reset HW bug in OMAP3430 ES3.x
where some of the efuse bits are not isolated during
wake-up from off mode. This can cause randomish
cold resets with off mode. Enabling the USBTLL hardware
SAVEANDRESTORE causes the core power up assert to be
delayed in a way that we will not get faulty values
when boot ROM is reading the unisolated registers.
Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi@digia.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
|
|
As per 3430 TRM, there are 6 banks [0 to 191]
Signed-off-by: Tom Rix <Tom.Rix@windriver.com>
Signed-off-by: Vikram Pandita <vikram.pandita@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
|
|
Xiaohui Xin and some other folks at Intel have been looking into what's
behind the performance hit of paravirt_ops when running native.
It appears that the hit is entirely due to the paravirtualized
spinlocks introduced by:
| commit 8efcbab674de2bee45a2e4cdf97de16b8e609ac8
| Date: Mon Jul 7 12:07:51 2008 -0700
|
| paravirt: introduce a "lock-byte" spinlock implementation
The extra call/return in the spinlock path is somehow
causing an increase in the cycles/instruction of somewhere around 2-7%
(seems to vary quite a lot from test to test). The working theory is
that the CPU's pipeline is getting upset about the
call->call->locked-op->return->return, and seems to be failing to
speculate (though I haven't seen anything definitive about the precise
reasons). This doesn't entirely make sense, because the performance
hit is also visible on unlock and other operations which don't involve
locked instructions. But spinlock operations clearly swamp all the
other pvops operations, even though I can't imagine that they're
nearly as common (there's only a .05% increase in instructions
executed).
If I disable just the pv-spinlock calls, my tests show that pvops is
identical to non-pvops performance on native (my measurements show that
it is actually about .1% faster, but Xiaohui shows a .05% slowdown).
Summary of results, averaging 10 runs of the "mmperf" test, using a
no-pvops build as baseline:
nopv Pv-nospin Pv-spin
CPU cycles 100.00% 99.89% 102.18%
instructions 100.00% 100.10% 100.15%
CPI 100.00% 99.79% 102.03%
cache ref 100.00% 100.84% 100.28%
cache miss 100.00% 90.47% 88.56%
cache miss rate 100.00% 89.72% 88.31%
branches 100.00% 99.93% 100.04%
branch miss 100.00% 103.66% 107.72%
branch miss rt 100.00% 103.73% 107.67%
wallclock 100.00% 99.90% 102.20%
The clear effect here is that the 2% increase in CPI is
directly reflected in the final wallclock time.
(The other interesting effect is that the more ops are
out of line calls via pvops, the lower the cache access
and miss rates. Not too surprising, but it suggests that
the non-pvops kernel is over-inlined. On the flipside,
the branch misses go up correspondingly...)
So, what's the fix?
Paravirt patching turns all the pvops calls into direct calls, so
_spin_lock etc do end up having direct calls. For example, the compiler
generated code for paravirtualized _spin_lock is:
<_spin_lock+0>: mov %gs:0xb4c8,%rax
<_spin_lock+9>: incl 0xffffffffffffe044(%rax)
<_spin_lock+15>: callq *0xffffffff805a5b30
<_spin_lock+22>: retq
The indirect call will get patched to:
<_spin_lock+0>: mov %gs:0xb4c8,%rax
<_spin_lock+9>: incl 0xffffffffffffe044(%rax)
<_spin_lock+15>: callq <__ticket_spin_lock>
<_spin_lock+20>: nop; nop /* or whatever 2-byte nop */
<_spin_lock+22>: retq
One possibility is to inline _spin_lock, etc, when building an
optimised kernel (ie, when there's no spinlock/preempt
instrumentation/debugging enabled). That will remove the outer
call/return pair, returning the instruction stream to a single
call/return, which will presumably execute the same as the non-pvops
case. The downsides arel 1) it will replicate the
preempt_disable/enable code at eack lock/unlock callsite; this code is
fairly small, but not nothing; and 2) the spinlock definitions are
already a very heavily tangled mass of #ifdefs and other preprocessor
magic, and making any changes will be non-trivial.
The other obvious answer is to disable pv-spinlocks. Making them a
separate config option is fairly easy, and it would be trivial to
enable them only when Xen is enabled (as the only non-default user).
But it doesn't really address the common case of a distro build which
is going to have Xen support enabled, and leaves the open question of
whether the native performance cost of pv-spinlocks is worth the
performance improvement on a loaded Xen system (10% saving of overall
system CPU when guests block rather than spin). Still it is a
reasonable short-term workaround.
[ Impact: fix pvops performance regression when running native ]
Analysed-by: "Xin Xiaohui" <xiaohui.xin@intel.com>
Analysed-by: "Li Xin" <xin.li@intel.com>
Analysed-by: "Nakajima Jun" <jun.nakajima@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Xen-devel <xen-devel@lists.xensource.com>
LKML-Reference: <4A0B62F7.5030802@goop.org>
[ fixed the help text ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
ASoC: DaVinci EVM board support buildfixes
ASoC: DaVinci I2S updates
ASoC: davinci-pcm buildfixes
ALSA: pcsp: fix printk format warning
ALSA: riptide: postfix increment and off by one
pxa2xx-ac97: fix reset gpio mode setting
ASoC: soc-core: fix crash when removing not instantiated card
|
