kernel-hacking-2024-linux-s.../arch/mn10300
Tejun Heo 0415b00d17 percpu: Always align percpu output section to PAGE_SIZE
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: Tejun Heo <tj@kernel.org>
Acked-by: Mike 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
2011-03-24 18:50:09 +01:00
..
boot MN10300: And Panasonic AM34 subarch and implement SMP 2010-10-27 17:28:55 +01:00
configs kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT 2011-01-20 17:02:05 -08:00
include/asm Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-mn10300 2011-03-24 10:07:50 -07:00
kernel percpu: Always align percpu output section to PAGE_SIZE 2011-03-24 18:50:09 +01:00
lib MN10300: And Panasonic AM34 subarch and implement SMP 2010-10-27 17:28:55 +01:00
mm MN10300: Create generic kernel debugger hooks 2011-03-18 16:54:30 +00:00
oprofile
proc-mn2ws0050 MN10300: Create general kernel debugger cache flushing 2011-03-18 16:54:30 +00:00
proc-mn103e010 MN10300: Create general kernel debugger cache flushing 2011-03-18 16:54:30 +00:00
unit-asb2303 MN10300: Generic time support 2010-10-27 17:28:57 +01:00
unit-asb2305 MN10300: Generic time support 2010-10-27 17:28:57 +01:00
unit-asb2364 MN10300: Clear ASB2364 peripheral interrupt masks before enabling interrupts 2011-03-18 16:52:54 +00:00
Kconfig MN10300: Use KGDB 2011-03-18 16:54:31 +00:00
Kconfig.debug MN10300: Deprecate gdbstub 2011-03-18 16:54:32 +00:00
Makefile MN10300: And Panasonic AM34 subarch and implement SMP 2010-10-27 17:28:55 +01:00