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  1. 25 3月, 2011 1 次提交
    • T
      percpu: Always align percpu output section to PAGE_SIZE · 0415b00d
      由 Tejun Heo 提交于 
      Percpu allocator honors alignment request upto PAGE_SIZE and both the
percpu addresses in the percpu address space and the translated kernel
addresses should be aligned accordingly.  The calculation of the
former depends on the alignment of percpu output section in the kernel
image.

The linker script macros PERCPU_VADDR() and PERCPU() are used to
define this output section and the latter takes @align parameter.
Several architectures are using @align smaller than PAGE_SIZE breaking
percpu memory alignment.

This patch removes @align parameter from PERCPU(), renames it to
PERCPU_SECTION() and makes it always align to PAGE_SIZE.  While at it,
add PCPU_SETUP_BUG_ON() checks such that alignment problems are
reliably detected and remove percpu alignment comment recently added
in workqueue.c as the condition would trigger BUG way before reaching
there.

For um, this patch raises the alignment of percpu area.  As the area
is in .init, there shouldn't be any noticeable difference.

This problem was discovered by David Howells while debugging boot
failure on mn10300.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: user-mode-linux-devel@lists.sourceforge.net
      0415b00d
  3. 25 1月, 2011 1 次提交
    • T
      percpu: align percpu readmostly subsection to cacheline · 19df0c2f
      由 Tejun Heo 提交于 
      Currently percpu readmostly subsection may share cachelines with other
percpu subsections which may result in unnecessary cacheline bounce
and performance degradation.

This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR()
linker macros, makes each arch linker scripts specify its cacheline
size and use it to align percpu subsections.

This is based on Shaohua's x86 only patch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Shaohua Li <shaohua.li@intel.com>
      19df0c2f
  5. 25 9月, 2009 1 次提交
  7. 09 7月, 2009 1 次提交
    • T
      linker script: unify usage of discard definition · 023bf6f1
      由 Tejun Heo 提交于 
      Discarded sections in different archs share some commonality but have
considerable differences.  This led to linker script for each arch
implementing its own /DISCARD/ definition, which makes maintaining
tedious and adding new entries error-prone.

This patch makes all linker scripts to move discard definitions to the
end of the linker script and use the common DISCARDS macro.  As ld
uses the first matching section definition, archs can include default
discarded sections by including them earlier in the linker script.

ia64 is notable because it first throws away some ia64 specific
subsections and then include the rest of the sections into the final
image, so those sections must be discarded before the inclusion.

defconfig compile tested for x86, x86-64, powerpc, powerpc64, ia64,
alpha, sparc, sparc64 and s390.  Michal Simek tested microblaze.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Tested-by: NMichal Simek <monstr@monstr.eu>
Cc: linux-arch@vger.kernel.org
Cc: Michal Simek <monstr@monstr.eu>
Cc: microblaze-uclinux@itee.uq.edu.au
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Tony Luck <tony.luck@intel.com>
      023bf6f1
  9. 24 6月, 2009 1 次提交
    • T
      linker script: throw away .discard section · 405d967d
      由 Tejun Heo 提交于 
      x86 throws away .discard section but no other archs do.  Also,
.discard is not thrown away while linking modules.  Make every arch
and module linking throw it away.  This will be used to define dummy
variables for percpu declarations and definitions.

This patch is based on Ivan Kokshaysky's alpha percpu patch.

[ Impact: always throw away everything in .discard ]
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
      405d967d
  11. 12 5月, 2009 1 次提交
    • C
      xtensa: Fix linker script to include .literal sections · 78f3cdfa
      由 Chris Zankel 提交于 
      Fix resembles implementation from Marc Gauthier and Piet Denaly:

In the Xtensa architecture, assembly generates literals which must always
precede the code (the L32R instruction that loads them only uses negative
PC-relative offsets).  For any *.text section, literals are placed in a
corresponding *.literal section.  The linker script (vmlinux.lds) must
place these in the correct order.  It must also combine them, when the
*.text section can be larger than L32R's 256 kB range.

For example, this doesn't work:  *(.literal) *(.text) because L32R
instructions at the end of .text can't reach the literals.

The linker can solve this if they are combined in parentheses, like this:
       *(.literal .text)
because it is now allowed mix literals in .text to bring them in range.

None of this is done by standard vmlinux.lds.h macros such as TEXT_TEXT
and INIT_TEXT.  To avoid replicating the logic of that header file, we
instead post-process the generated linker script to convert *(xxx.text)
to *(xxx.literal xxx.text) for the following text sections:
       .text .ref.text .*init.text .*exit.text .text.*
using a sed script.  To do this we must override the default rule for
vmlinux.lds (see scripts/Makefile.build and the top-level Makefile)
to insert this extra step.
Signed-off-by: NMarc Gauthier <marc@tensilica.com>
Signed-off-by: NPete Delaney <piet@tensilica.com>
Signed-off-by: NChris Zankel <chris@zankel.net>
      78f3cdfa
  13. 27 4月, 2009 1 次提交
  15. 03 4月, 2009 1 次提交
  17. 07 11月, 2008 1 次提交
  19. 14 2月, 2008 2 次提交
  21. 29 1月, 2008 1 次提交
  23. 20 7月, 2007 1 次提交
    • F
      define new percpu interface for shared data · 5fb7dc37
      由 Fenghua Yu 提交于 
      per cpu data section contains two types of data.  One set which is
exclusively accessed by the local cpu and the other set which is per cpu,
but also shared by remote cpus.  In the current kernel, these two sets are
not clearely separated out.  This can potentially cause the same data
cacheline shared between the two sets of data, which will result in
unnecessary bouncing of the cacheline between cpus.

One way to fix the problem is to cacheline align the remotely accessed per
cpu data, both at the beginning and at the end.  Because of the padding at
both ends, this will likely cause some memory wastage and also the
interface to achieve this is not clean.

This patch:

Moves the remotely accessed per cpu data (which is currently marked
as ____cacheline_aligned_in_smp) into a different section, where all the data
elements are cacheline aligned. And as such, this differentiates the local
only data and remotely accessed data cleanly.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5fb7dc37
  25. 17 7月, 2007 1 次提交
  27. 01 6月, 2007 1 次提交
    • C
      [XTENSA] clean-up header files · de4f6e5b
      由 Chris Zankel 提交于 
      The header files in the asm-xtensa directory are not clean and
'make headers_check' fails. This is a first patch to fix most of
the header files. It removes unnecessary include statements and
adds some that are required for building the kernel. The linker
script required some updates or the linking stage would fail.
Signed-off-by: NChris Zankel <chris@zankel.net>
      de4f6e5b
  29. 19 5月, 2007 2 次提交
  31. 03 5月, 2007 1 次提交
  33. 12 2月, 2007 1 次提交
  35. 11 12月, 2006 2 次提交
  37. 28 10月, 2006 1 次提交
  39. 01 7月, 2006 1 次提交
  41. 13 7月, 2005 1 次提交
  43. 24 6月, 2005 1 次提交