Ingo recently introduced a great speedup for allocating new mmaps using the
free_area_cache pointer which boosts the specweb SSL benchmark by 4-5% and
causes huge performance increases in thread creation.
The downside of this patch is that it does lead to fragmentation in the
mmap-ed areas (visible via /proc/self/maps), such that some applications
that work fine under 2.4 kernels quickly run out of memory on any 2.6
kernel.
The problem is twofold:
1) the free_area_cache is used to continue a search for memory where
the last search ended. Before the change new areas were always
searched from the base address on.
So now new small areas are cluttering holes of all sizes
throughout the whole mmap-able region whereas before small holes
tended to close holes near the base leaving holes far from the base
large and available for larger requests.
2) the free_area_cache also is set to the location of the last
munmap-ed area so in scenarios where we allocate e.g. five regions of
1K each, then free regions 4 2 3 in this order the next request for 1K
will be placed in the position of the old region 3, whereas before we
appended it to the still active region 1, placing it at the location
of the old region 2. Before we had 1 free region of 2K, now we only
get two free regions of 1K -> fragmentation.
The patch addresses thes issues by introducing yet another cache descriptor
cached_hole_size that contains the largest known hole size below the
current free_area_cache. If a new request comes in the size is compared
against the cached_hole_size and if the request can be filled with a hole
below free_area_cache the search is started from the base instead.
The results look promising: Whereas 2.6.12-rc4 fragments quickly and my
(earlier posted) leakme.c test program terminates after 50000+ iterations
with 96 distinct and fragmented maps in /proc/self/maps it performs nicely
(as expected) with thread creation, Ingo's test_str02 with 20000 threads
requires 0.7s system time.
Taking out Ingo's patch (un-patch available per request) by basically
deleting all mentions of free_area_cache from the kernel and starting the
search for new memory always at the respective bases we observe: leakme
terminates successfully with 11 distinctive hardly fragmented areas in
/proc/self/maps but thread creating is gringdingly slow: 30+s(!) system
time for Ingo's test_str02 with 20000 threads.
Now - drumroll ;-) the appended patch works fine with leakme: it ends with
only 7 distinct areas in /proc/self/maps and also thread creation seems
sufficiently fast with 0.71s for 20000 threads.
Signed-off-by: Wolfgang Wander <wwc@rentec.com>
Credit-to: "Richard Purdie" <rpurdie@rpsys.net>
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu> (partly)
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Lennert Buytenhek
The ixp2000 defconfigs are among the few that do not enable module
support by default. I keep enabling module support by hand for every
new kernel version, so let's just make this change upstream.
Signed-off-by: Lennert Buytenhek
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Richard Purdie
Fix typo in sharpsl_param.c so it works correctly on collie.
Signed-off-by: Richard Purdie
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
The IXP2000 has four timers, but if we're on an A-step IXP2800, timer
2 and 3 don't work. We need two timers for timekeeping (one for the
timer interrupt and one for tracking missed jiffies), so on early
IXP2800s we have no other choice but to use timer 1 and 4 for that,
but on all other IXP2000s we'd rather leave timer 4 free since that's
the only timer we can use for the watchdog.
So, on buggy IXP2000s (i.e. the A-step IXP2800) we use timer 4 for
tracking missed jiffies, and on all all non-buggy IXP2000s (i.e.
everything but the A-step IXP2800) we use timer 2.
On a pre-production IXP2800, this patch should print these messages
on boot:
Enabling IXP2800 erratum #25 workaround
Unable to use IXP2000 watchdog due to IXP2800 erratum #25
On any non-buggy IXP2800 (as well as on IXP2400s) you shouldn't see
anything at all, and the watchdog should be usable again.
Signed-off-by: Lennert Buytenhek
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Catalin Marinas
This patch adds PCI support for the Versatile PB926 platform.
Signed-off-by: Colin King
Signed-off-by: Catalin Marinas
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Bellido Nicolas
Core support for AAEC-2000 based platforms.
This is an updated version of the previous patch, and takes
into account Russell's comments.
AAED-2000 default configuration will follow as soon
as some problems with the bootloader are sorted out...
Signed-off-by: Nicolas Bellido
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When DMA bounce buffers were unmapped and the data was memcpy'd to
the original buffer, we were not ensuring that the data was written
to RAM. This means that there was the potential for page cache
pages to have different cache states depending whether they've been
bounced or not.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
flush_dcache_page() did nothing for these caches, but since they
suffer from I/D cache coherency issues, we need to ensure that data
is written back to RAM.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We need to re-initialise the stack pointers for undefined, IRQ
and abort mode handlers whenever we resume.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Create a temporary page table to startup secondary processors. This
page table must have a 1:1 virtual/physical mapping for the kernel
in addition to the standard mappings to ensure that the secondary
CPU can enable its MMU safely.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
Without this some devices fail to work again after a suspend event.
Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Catalin Marinas
The GPIO base for Integrator/CP is different from the
Integrator/AP. This patch sets the correct value for
INTEGRATOR_GPIO_BASE.
Signed-off-by: Catalin Marinas
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Catalin Marinas
The current red and blue colours on the Versatile CLCD are
reversed when the 5:6:5 mode is used. The patch sets the proper
bit in the SYS_CLCD register value.
Signed-off-by: Catalin Marinas
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from David Brownell
The ARM generic Kconfig filters out IDE options ... except for
an error prone ARMload of special cases.
This adds one general case to the systems that will offer IDE options:
kernels with PCMCIA support, which probably want to use IDE to access
CompactFlash cards. This might allow many (most?) of the other cases
to disappear, for systems that only see IDE hardware through CF cards.
Right now this one patch is used to gate access to CF cards, including
MicroDrives, for both omap_cf and at91_cf drivers.
Signed-off-by: David Brownell
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Vincent Sanders
This fixes the "multiple definitions of cpufreq_get" build faliure on
the hackkit SA1100 platform.
Signed-off-by: Vincent Sanders
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Vincent Sanders
This fixes the "multiple definitions of cpufreq_get" build faliure on
the Badge4 SA1100 platform.
Signed-off-by: Vincent Sanders
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Dave Neuer
This fixes the "multiple definitions of cpufreq_get" errors on
StrongARM-based iPAQs.
Signed-off-by: Dave Neuer
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
Not that there might be many of them on the planet, but at least RMK
apparently has one.
Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The ARM copypage changes in 2.6.12-rc4-git1 removed the preempt locking
from the copypage functions which broke the XScale implementation.
This patch fixes the locking on XScale and removes the now unneeded
minicache code.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Checked-by: Richard Purdie
Patch from Todd Poynor
PXA27x sleep fixes:
* set additional sleep/wakeup registers for Mainstone boards.
* move CKEN=0 to pxa25x-specific code; that value is harmful on pxa27x.
* save/restore additional registers, including some found necessary for
C5 processors and/or newer blob versions.
* enable future support of additional sleep modes for PXA27x (eg,
standby, deep sleep).
* split off cpu-specific sleep processing between pxa27x and pxa25x into
separate files (partly in preparation for additional sleep modes).
Includes fixes from David Burrage.
Signed-off-by: Todd Poynor
Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Albrecht Dreß
Problem:
When a module requests a DMA channel via the function s3c2410_dma_request(), this function requests the appropriate irq under the name of the client module. When the client module is unloaded, it calls s3c2410_dma_free() which does not free the irq. Consequently, when e.g. running "cat /proc/interrupts", the irq owner points to freed memory, leading to a kernel oops.
File:
linux/arch/arm/mach-s3c2410/dma.c
Fix:
trivial, below
Signed-off-by: Albrecht Dreß
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The current vector entry system does not allow for SMP. In
order to work around this, we need to eliminate our reliance
on the fixed save areas, which breaks the way we enable
alignment traps. This patch changes the way we handle the
save areas such that we can have one per CPU.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
The current vector entry system does not allow for SMP. In
order to work around this, we need to eliminate our reliance
on the fixed save areas, which breaks the way we enable
alignment traps. This patch makes the alignment trap enable
code independent of the way we handle the save areas.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
By changing r9 -> r8 and r8 to 'tsk' (r9) we are able to remove
one instruction from the preempt path.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Patch from Ben Dooks
Fix the setting of hdiv when set to divide-by-2. Thanks to
Jeonghoon Yoon for pointing this out.
Change name of the NAND device to "s3c2440-nand" as it
is not similar enough to the "s3c2410-nand" device.
Signed-off-by: Ben Dooks
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
S3C2440 UPLL is the same as the S3C2410 UPLL, it is only the
MPLL which has an extra multiplication factor of 2 in the
multiplier.
Signed-off-by: Ben Dooks
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
Not all ARMv6 processors implement the TLS register.
Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move the locking for copy_user_page() and clear_user_page() into
the implementations which require locking. For simple memcpy/
memset based implementations, the locking is extra overhead which
is not necessary, and prevents preemption occuring.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Wolfgang Wander