The patch titled
alpha: use generic percpu support
has been added to the -mm tree. Its filename is
alpha-use-generic-percpu-support.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: alpha: use generic percpu support
From: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
The percpu support for alpha currently expects a percpu variable to be
passed to SHIFT_PERCPU_PTR. However, SHIFT_PERCPU_PTR takes a pointer
and not a variable. This breaks code that uses SHIFT_PERCPU_PTR on a
pointer.
Simply switch alpha to use generic cpu.
The purpose of the special percpu code seems to be optmization. That
could be done by modifying the per_cpu_var() (and related) macros which
indeed take a variable as a parameter.
Signed-off-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
Cc: Jay Estabrook <jay.estabrook@xxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: Richard Henderson <rth@xxxxxxxxxxx>
CC: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/alpha/include/asm/percpu.h | 77 ------------------------------
1 file changed, 1 insertion(+), 76 deletions(-)
diff -puN arch/alpha/include/asm/percpu.h~alpha-use-generic-percpu-support arch/alpha/include/asm/percpu.h
--- a/arch/alpha/include/asm/percpu.h~alpha-use-generic-percpu-support
+++ a/arch/alpha/include/asm/percpu.h
@@ -1,79 +1,4 @@
#ifndef __ALPHA_PERCPU_H
#define __ALPHA_PERCPU_H
-#include <linux/compiler.h>
-#include <linux/threads.h>
-
-/*
- * Determine the real variable name from the name visible in the
- * kernel sources.
- */
-#define per_cpu_var(var) per_cpu__##var
-
-#ifdef CONFIG_SMP
-
-/*
- * per_cpu_offset() is the offset that has to be added to a
- * percpu variable to get to the instance for a certain processor.
- */
-extern unsigned long __per_cpu_offset[NR_CPUS];
-
-#define per_cpu_offset(x) (__per_cpu_offset[x])
-
-#define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
-#ifdef CONFIG_DEBUG_PREEMPT
-#define my_cpu_offset per_cpu_offset(smp_processor_id())
-#else
-#define my_cpu_offset __my_cpu_offset
-#endif
-
-#ifndef MODULE
-#define SHIFT_PERCPU_PTR(var, offset) RELOC_HIDE(&per_cpu_var(var), (offset))
-#define PER_CPU_ATTRIBUTES
-#else
-/*
- * To calculate addresses of locally defined variables, GCC uses 32-bit
- * displacement from the GP. Which doesn't work for per cpu variables in
- * modules, as an offset to the kernel per cpu area is way above 4G.
- *
- * This forces allocation of a GOT entry for per cpu variable using
- * ldq instruction with a 'literal' relocation.
- */
-#define SHIFT_PERCPU_PTR(var, offset) ({ \
- extern int simple_identifier_##var(void); \
- unsigned long __ptr, tmp_gp; \
- asm ( "br %1, 1f \n\
- 1: ldgp %1, 0(%1) \n\
- ldq %0, per_cpu__" #var"(%1)\t!literal" \
- : "=&r"(__ptr), "=&r"(tmp_gp)); \
- (typeof(&per_cpu_var(var)))(__ptr + (offset)); })
-
-#define PER_CPU_ATTRIBUTES __used
-
-#endif /* MODULE */
-
-/*
- * A percpu variable may point to a discarded regions. The following are
- * established ways to produce a usable pointer from the percpu variable
- * offset.
- */
-#define per_cpu(var, cpu) \
- (*SHIFT_PERCPU_PTR(var, per_cpu_offset(cpu)))
-#define __get_cpu_var(var) \
- (*SHIFT_PERCPU_PTR(var, my_cpu_offset))
-#define __raw_get_cpu_var(var) \
- (*SHIFT_PERCPU_PTR(var, __my_cpu_offset))
-
-#else /* ! SMP */
-
-#define per_cpu(var, cpu) (*((void)(cpu), &per_cpu_var(var)))
-#define __get_cpu_var(var) per_cpu_var(var)
-#define __raw_get_cpu_var(var) per_cpu_var(var)
-#define per_cpu_offset(x) 0
-
-#define PER_CPU_ATTRIBUTES
-
-#endif /* SMP */
-
-#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu_var(name)
-
+#include <asm-generic/percpu.h>
#endif /* __ALPHA_PERCPU_H */
_
Patches currently in -mm which might be from cl@xxxxxxxxxxxxxxxxxxxx are
hugetlbfs-handle-pages-higher-order-than-max_order.patch
hugetlb-pull-gigantic-page-initialisation-out-of-the-default-path.patch
oom-do-not-dump-task-state-for-non-thread-group-leaders.patch
mm-move-migrate_prep-out-from-under-mmap_sem.patch
vmemmap-warn-about-page_structs-with-remote-distance.patch
repeatable-slab-corruption-with-ltp-msgctl08.patch
linux-next.patch
cpusets-update-mems-allowed-in-page-allocator.patch
cpusets-update-mems-allowed-in-page-allocator-fix.patch
mm-rework-do_pages_move-to-work-on-page_sized-chunks.patch
mm-rework-do_pages_move-to-work-on-page_sized-chunks-update.patch
mm-move_pages-no-need-to-set-pp-page-to-zero_page0-by-default.patch
alpha-use-generic-percpu-support.patch
reiser4.patch
slab-leaks3-default-y.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
