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authorLinus Torvalds <torvalds@linux-foundation.org>2017-10-03 10:05:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-10-03 10:05:12 -0700
commitff93026d51935b671b4ac131886f0914f8b6189a (patch)
tree03bbcdb1eb122fbe830e0517e570112aaf2e5412 /include
parentc1de1591d927bc1e55095d642b3c3cc2e54fc1cd (diff)
parent1fa4df3e688902d033dfda796eb83ae6ad8d0488 (diff)
Merge branch 'for-4.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu fixes from Tejun Heo: "Rather important fixes this time. - The new percpu area allocator had a subtle bug in how it iterates the memory regions and could skip viable areas, which led to allocation failures for module static percpu variables. Dennis fixed the bug and another non-critical one in stat calculation. - Mark noticed that the generic implementations of percpu local atomic reads aren't properly protected against irqs and there's a (slim) chance for split reads on some 32bit systems. Generic implementations are updated to disable irq when read size is larger than ulong size. This may have made some 32bit archs which can do atomic local 64bit accesses generate sub-optimal code. We need to find them out and implement arch-specific overrides" * 'for-4.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: fix iteration to prevent skipping over block percpu: fix starting offset for chunk statistics traversal percpu: make this_cpu_generic_read() atomic w.r.t. interrupts
Diffstat (limited to 'include')
-rw-r--r--include/asm-generic/percpu.h24
1 files changed, 22 insertions, 2 deletions
diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index 0504ef8f3aa3..976f8ac26665 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -115,15 +115,35 @@ do { \
(__ret); \
})
-#define this_cpu_generic_read(pcp) \
+#define __this_cpu_generic_read_nopreempt(pcp) \
({ \
typeof(pcp) __ret; \
preempt_disable_notrace(); \
- __ret = raw_cpu_generic_read(pcp); \
+ __ret = READ_ONCE(*raw_cpu_ptr(&(pcp))); \
preempt_enable_notrace(); \
__ret; \
})
+#define __this_cpu_generic_read_noirq(pcp) \
+({ \
+ typeof(pcp) __ret; \
+ unsigned long __flags; \
+ raw_local_irq_save(__flags); \
+ __ret = raw_cpu_generic_read(pcp); \
+ raw_local_irq_restore(__flags); \
+ __ret; \
+})
+
+#define this_cpu_generic_read(pcp) \
+({ \
+ typeof(pcp) __ret; \
+ if (__native_word(pcp)) \
+ __ret = __this_cpu_generic_read_nopreempt(pcp); \
+ else \
+ __ret = __this_cpu_generic_read_noirq(pcp); \
+ __ret; \
+})
+
#define this_cpu_generic_to_op(pcp, val, op) \
do { \
unsigned long __flags; \