From 23fb064bb96f001ecb8682129f7ee1bc1ca691bc Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 21 Jul 2009 21:18:35 +0900 Subject: percpu: kill legacy percpu allocator With ia64 converted, there's no arch left which still uses legacy percpu allocator. Kill it. Signed-off-by: Tejun Heo Delightedly-acked-by: Rusty Russell Cc: Ingo Molnar Cc: Christoph Lameter --- include/linux/percpu.h | 24 ------------------------ 1 file changed, 24 deletions(-) (limited to 'include') diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 878836ca999c..5baf5b8788fb 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -34,8 +34,6 @@ #ifdef CONFIG_SMP -#ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA - /* minimum unit size, also is the maximum supported allocation size */ #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10) @@ -130,28 +128,6 @@ extern int __init pcpu_page_first_chunk(size_t reserved_size, #define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu))) extern void *__alloc_reserved_percpu(size_t size, size_t align); - -#else /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */ - -struct percpu_data { - void *ptrs[1]; -}; - -/* pointer disguising messes up the kmemleak objects tracking */ -#ifndef CONFIG_DEBUG_KMEMLEAK -#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata) -#else -#define __percpu_disguise(pdata) (struct percpu_data *)(pdata) -#endif - -#define per_cpu_ptr(ptr, cpu) \ -({ \ - struct percpu_data *__p = __percpu_disguise(ptr); \ - (__typeof__(ptr))__p->ptrs[(cpu)]; \ -}) - -#endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */ - extern void *__alloc_percpu(size_t size, size_t align); extern void free_percpu(void *__pdata); -- cgit v1.2.3 From 7340a0b15280c9d902c7dd0608b8e751b5a7c403 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Sat, 3 Oct 2009 19:48:22 +0900 Subject: this_cpu: Introduce this_cpu_ptr() and generic this_cpu_* operations This patch introduces two things: First this_cpu_ptr and then per cpu atomic operations. this_cpu_ptr ------------ A common operation when dealing with cpu data is to get the instance of the cpu data associated with the currently executing processor. This can be optimized by this_cpu_ptr(xx) = per_cpu_ptr(xx, smp_processor_id). The problem with per_cpu_ptr(x, smp_processor_id) is that it requires an array lookup to find the offset for the cpu. Processors typically have the offset for the current cpu area in some kind of (arch dependent) efficiently accessible register or memory location. We can use that instead of doing the array lookup to speed up the determination of the address of the percpu variable. This is particularly significant because these lookups occur in performance critical paths of the core kernel. this_cpu_ptr() can avoid memory accesses and this_cpu_ptr comes in two flavors. The preemption context matters since we are referring the the currently executing processor. In many cases we must insure that the processor does not change while a code segment is executed. __this_cpu_ptr -> Do not check for preemption context this_cpu_ptr -> Check preemption context The parameter to these operations is a per cpu pointer. This can be the address of a statically defined per cpu variable (&per_cpu_var(xxx)) or the address of a per cpu variable allocated with the per cpu allocator. per cpu atomic operations: this_cpu_*(var, val) ----------------------------------------------- this_cpu_* operations (like this_cpu_add(struct->y, value) operate on abitrary scalars that are members of structures allocated with the new per cpu allocator. They can also operate on static per_cpu variables if they are passed to per_cpu_var() (See patch to use this_cpu_* operations for vm statistics). These operations are guaranteed to be atomic vs preemption when modifying the scalar. The calculation of the per cpu offset is also guaranteed to be atomic at the same time. This means that a this_cpu_* operation can be safely used to modify a per cpu variable in a context where interrupts are enabled and preemption is allowed. Many architectures can perform such a per cpu atomic operation with a single instruction. Note that the atomicity here is different from regular atomic operations. Atomicity is only guaranteed for data accessed from the currently executing processor. Modifications from other processors are still possible. There must be other guarantees that the per cpu data is not modified from another processor when using these instruction. The per cpu atomicity is created by the fact that the processor either executes and instruction or not. Embedded in the instruction is the relocation of the per cpu address to the are reserved for the current processor and the RMW action. Therefore interrupts or preemption cannot occur in the mids of this processing. Generic fallback functions are used if an arch does not define optimized this_cpu operations. The functions come also come in the two flavors used for this_cpu_ptr(). The firstparameter is a scalar that is a member of a structure allocated through allocpercpu or a per cpu variable (use per_cpu_var(xxx)). The operations are similar to what percpu_add() and friends do. this_cpu_read(scalar) this_cpu_write(scalar, value) this_cpu_add(scale, value) this_cpu_sub(scalar, value) this_cpu_inc(scalar) this_cpu_dec(scalar) this_cpu_and(scalar, value) this_cpu_or(scalar, value) this_cpu_xor(scalar, value) Arch code can override the generic functions and provide optimized atomic per cpu operations. These atomic operations must provide both the relocation (x86 does it through a segment override) and the operation on the data in a single instruction. Otherwise preempt needs to be disabled and there is no gain from providing arch implementations. A third variant is provided prefixed by irqsafe_. These variants are safe against hardware interrupts on the *same* processor (all per cpu atomic primitives are *always* *only* providing safety for code running on the *same* processor!). The increment needs to be implemented by the hardware in such a way that it is a single RMW instruction that is either processed before or after an interrupt. cc: David Howells cc: Ingo Molnar cc: Rusty Russell cc: Eric Dumazet Signed-off-by: Christoph Lameter Signed-off-by: Tejun Heo --- include/asm-generic/percpu.h | 5 + include/linux/percpu.h | 400 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 405 insertions(+) (limited to 'include') diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h index 90079c373f1c..8087b90d4673 100644 --- a/include/asm-generic/percpu.h +++ b/include/asm-generic/percpu.h @@ -56,6 +56,9 @@ extern unsigned long __per_cpu_offset[NR_CPUS]; #define __raw_get_cpu_var(var) \ (*SHIFT_PERCPU_PTR(&per_cpu_var(var), __my_cpu_offset)) +#define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset) +#define __this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset) + #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA extern void setup_per_cpu_areas(void); @@ -66,6 +69,8 @@ extern void setup_per_cpu_areas(void); #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 this_cpu_ptr(ptr) per_cpu_ptr(ptr, 0) +#define __this_cpu_ptr(ptr) this_cpu_ptr(ptr) #endif /* SMP */ diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 5baf5b8788fb..3d9ba92b104f 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -219,4 +219,404 @@ do { \ # define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=) #endif +/* + * Branching function to split up a function into a set of functions that + * are called for different scalar sizes of the objects handled. + */ + +extern void __bad_size_call_parameter(void); + +#define __size_call_return(stem, variable) \ +({ typeof(variable) ret__; \ + switch(sizeof(variable)) { \ + case 1: ret__ = stem##1(variable);break; \ + case 2: ret__ = stem##2(variable);break; \ + case 4: ret__ = stem##4(variable);break; \ + case 8: ret__ = stem##8(variable);break; \ + default: \ + __bad_size_call_parameter();break; \ + } \ + ret__; \ +}) + +#define __size_call(stem, variable, ...) \ +do { \ + switch(sizeof(variable)) { \ + case 1: stem##1(variable, __VA_ARGS__);break; \ + case 2: stem##2(variable, __VA_ARGS__);break; \ + case 4: stem##4(variable, __VA_ARGS__);break; \ + case 8: stem##8(variable, __VA_ARGS__);break; \ + default: \ + __bad_size_call_parameter();break; \ + } \ +} while (0) + +/* + * Optimized manipulation for memory allocated through the per cpu + * allocator or for addresses of per cpu variables (can be determined + * using per_cpu_var(xx). + * + * These operation guarantee exclusivity of access for other operations + * on the *same* processor. The assumption is that per cpu data is only + * accessed by a single processor instance (the current one). + * + * The first group is used for accesses that must be done in a + * preemption safe way since we know that the context is not preempt + * safe. Interrupts may occur. If the interrupt modifies the variable + * too then RMW actions will not be reliable. + * + * The arch code can provide optimized functions in two ways: + * + * 1. Override the function completely. F.e. define this_cpu_add(). + * The arch must then ensure that the various scalar format passed + * are handled correctly. + * + * 2. Provide functions for certain scalar sizes. F.e. provide + * this_cpu_add_2() to provide per cpu atomic operations for 2 byte + * sized RMW actions. If arch code does not provide operations for + * a scalar size then the fallback in the generic code will be + * used. + */ + +#define _this_cpu_generic_read(pcp) \ +({ typeof(pcp) ret__; \ + preempt_disable(); \ + ret__ = *this_cpu_ptr(&(pcp)); \ + preempt_enable(); \ + ret__; \ +}) + +#ifndef this_cpu_read +# ifndef this_cpu_read_1 +# define this_cpu_read_1(pcp) _this_cpu_generic_read(pcp) +# endif +# ifndef this_cpu_read_2 +# define this_cpu_read_2(pcp) _this_cpu_generic_read(pcp) +# endif +# ifndef this_cpu_read_4 +# define this_cpu_read_4(pcp) _this_cpu_generic_read(pcp) +# endif +# ifndef this_cpu_read_8 +# define this_cpu_read_8(pcp) _this_cpu_generic_read(pcp) +# endif +# define this_cpu_read(pcp) __size_call_return(this_cpu_read_, (pcp)) +#endif + +#define _this_cpu_generic_to_op(pcp, val, op) \ +do { \ + preempt_disable(); \ + *__this_cpu_ptr(&pcp) op val; \ + preempt_enable(); \ +} while (0) + +#ifndef this_cpu_write +# ifndef this_cpu_write_1 +# define this_cpu_write_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), =) +# endif +# ifndef this_cpu_write_2 +# define this_cpu_write_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), =) +# endif +# ifndef this_cpu_write_4 +# define this_cpu_write_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), =) +# endif +# ifndef this_cpu_write_8 +# define this_cpu_write_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), =) +# endif +# define this_cpu_write(pcp, val) __size_call(this_cpu_write_, (pcp), (val)) +#endif + +#ifndef this_cpu_add +# ifndef this_cpu_add_1 +# define this_cpu_add_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=) +# endif +# ifndef this_cpu_add_2 +# define this_cpu_add_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=) +# endif +# ifndef this_cpu_add_4 +# define this_cpu_add_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=) +# endif +# ifndef this_cpu_add_8 +# define this_cpu_add_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=) +# endif +# define this_cpu_add(pcp, val) __size_call(this_cpu_add_, (pcp), (val)) +#endif + +#ifndef this_cpu_sub +# define this_cpu_sub(pcp, val) this_cpu_add((pcp), -(val)) +#endif + +#ifndef this_cpu_inc +# define this_cpu_inc(pcp) this_cpu_add((pcp), 1) +#endif + +#ifndef this_cpu_dec +# define this_cpu_dec(pcp) this_cpu_sub((pcp), 1) +#endif + +#ifndef this_cpu_and +# ifndef this_cpu_and_1 +# define this_cpu_and_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=) +# endif +# ifndef this_cpu_and_2 +# define this_cpu_and_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=) +# endif +# ifndef this_cpu_and_4 +# define this_cpu_and_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=) +# endif +# ifndef this_cpu_and_8 +# define this_cpu_and_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=) +# endif +# define this_cpu_and(pcp, val) __size_call(this_cpu_and_, (pcp), (val)) +#endif + +#ifndef this_cpu_or +# ifndef this_cpu_or_1 +# define this_cpu_or_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=) +# endif +# ifndef this_cpu_or_2 +# define this_cpu_or_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=) +# endif +# ifndef this_cpu_or_4 +# define this_cpu_or_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=) +# endif +# ifndef this_cpu_or_8 +# define this_cpu_or_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=) +# endif +# define this_cpu_or(pcp, val) __size_call(this_cpu_or_, (pcp), (val)) +#endif + +#ifndef this_cpu_xor +# ifndef this_cpu_xor_1 +# define this_cpu_xor_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=) +# endif +# ifndef this_cpu_xor_2 +# define this_cpu_xor_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=) +# endif +# ifndef this_cpu_xor_4 +# define this_cpu_xor_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=) +# endif +# ifndef this_cpu_xor_8 +# define this_cpu_xor_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=) +# endif +# define this_cpu_xor(pcp, val) __size_call(this_cpu_or_, (pcp), (val)) +#endif + +/* + * Generic percpu operations that do not require preemption handling. + * Either we do not care about races or the caller has the + * responsibility of handling preemptions issues. Arch code can still + * override these instructions since the arch per cpu code may be more + * efficient and may actually get race freeness for free (that is the + * case for x86 for example). + * + * If there is no other protection through preempt disable and/or + * disabling interupts then one of these RMW operations can show unexpected + * behavior because the execution thread was rescheduled on another processor + * or an interrupt occurred and the same percpu variable was modified from + * the interrupt context. + */ +#ifndef __this_cpu_read +# ifndef __this_cpu_read_1 +# define __this_cpu_read_1(pcp) (*__this_cpu_ptr(&(pcp))) +# endif +# ifndef __this_cpu_read_2 +# define __this_cpu_read_2(pcp) (*__this_cpu_ptr(&(pcp))) +# endif +# ifndef __this_cpu_read_4 +# define __this_cpu_read_4(pcp) (*__this_cpu_ptr(&(pcp))) +# endif +# ifndef __this_cpu_read_8 +# define __this_cpu_read_8(pcp) (*__this_cpu_ptr(&(pcp))) +# endif +# define __this_cpu_read(pcp) __size_call_return(__this_cpu_read_, (pcp)) +#endif + +#define __this_cpu_generic_to_op(pcp, val, op) \ +do { \ + *__this_cpu_ptr(&(pcp)) op val; \ +} while (0) + +#ifndef __this_cpu_write +# ifndef __this_cpu_write_1 +# define __this_cpu_write_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), =) +# endif +# ifndef __this_cpu_write_2 +# define __this_cpu_write_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), =) +# endif +# ifndef __this_cpu_write_4 +# define __this_cpu_write_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), =) +# endif +# ifndef __this_cpu_write_8 +# define __this_cpu_write_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), =) +# endif +# define __this_cpu_write(pcp, val) __size_call(__this_cpu_write_, (pcp), (val)) +#endif + +#ifndef __this_cpu_add +# ifndef __this_cpu_add_1 +# define __this_cpu_add_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=) +# endif +# ifndef __this_cpu_add_2 +# define __this_cpu_add_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=) +# endif +# ifndef __this_cpu_add_4 +# define __this_cpu_add_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=) +# endif +# ifndef __this_cpu_add_8 +# define __this_cpu_add_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=) +# endif +# define __this_cpu_add(pcp, val) __size_call(__this_cpu_add_, (pcp), (val)) +#endif + +#ifndef __this_cpu_sub +# define __this_cpu_sub(pcp, val) __this_cpu_add((pcp), -(val)) +#endif + +#ifndef __this_cpu_inc +# define __this_cpu_inc(pcp) __this_cpu_add((pcp), 1) +#endif + +#ifndef __this_cpu_dec +# define __this_cpu_dec(pcp) __this_cpu_sub((pcp), 1) +#endif + +#ifndef __this_cpu_and +# ifndef __this_cpu_and_1 +# define __this_cpu_and_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=) +# endif +# ifndef __this_cpu_and_2 +# define __this_cpu_and_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=) +# endif +# ifndef __this_cpu_and_4 +# define __this_cpu_and_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=) +# endif +# ifndef __this_cpu_and_8 +# define __this_cpu_and_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=) +# endif +# define __this_cpu_and(pcp, val) __size_call(__this_cpu_and_, (pcp), (val)) +#endif + +#ifndef __this_cpu_or +# ifndef __this_cpu_or_1 +# define __this_cpu_or_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=) +# endif +# ifndef __this_cpu_or_2 +# define __this_cpu_or_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=) +# endif +# ifndef __this_cpu_or_4 +# define __this_cpu_or_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=) +# endif +# ifndef __this_cpu_or_8 +# define __this_cpu_or_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=) +# endif +# define __this_cpu_or(pcp, val) __size_call(__this_cpu_or_, (pcp), (val)) +#endif + +#ifndef __this_cpu_xor +# ifndef __this_cpu_xor_1 +# define __this_cpu_xor_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=) +# endif +# ifndef __this_cpu_xor_2 +# define __this_cpu_xor_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=) +# endif +# ifndef __this_cpu_xor_4 +# define __this_cpu_xor_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=) +# endif +# ifndef __this_cpu_xor_8 +# define __this_cpu_xor_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=) +# endif +# define __this_cpu_xor(pcp, val) __size_call(__this_cpu_xor_, (pcp), (val)) +#endif + +/* + * IRQ safe versions of the per cpu RMW operations. Note that these operations + * are *not* safe against modification of the same variable from another + * processors (which one gets when using regular atomic operations) + . They are guaranteed to be atomic vs. local interrupts and + * preemption only. + */ +#define irqsafe_cpu_generic_to_op(pcp, val, op) \ +do { \ + unsigned long flags; \ + local_irq_save(flags); \ + *__this_cpu_ptr(&(pcp)) op val; \ + local_irq_restore(flags); \ +} while (0) + +#ifndef irqsafe_cpu_add +# ifndef irqsafe_cpu_add_1 +# define irqsafe_cpu_add_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=) +# endif +# ifndef irqsafe_cpu_add_2 +# define irqsafe_cpu_add_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=) +# endif +# ifndef irqsafe_cpu_add_4 +# define irqsafe_cpu_add_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=) +# endif +# ifndef irqsafe_cpu_add_8 +# define irqsafe_cpu_add_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=) +# endif +# define irqsafe_cpu_add(pcp, val) __size_call(irqsafe_cpu_add_, (pcp), (val)) +#endif + +#ifndef irqsafe_cpu_sub +# define irqsafe_cpu_sub(pcp, val) irqsafe_cpu_add((pcp), -(val)) +#endif + +#ifndef irqsafe_cpu_inc +# define irqsafe_cpu_inc(pcp) irqsafe_cpu_add((pcp), 1) +#endif + +#ifndef irqsafe_cpu_dec +# define irqsafe_cpu_dec(pcp) irqsafe_cpu_sub((pcp), 1) +#endif + +#ifndef irqsafe_cpu_and +# ifndef irqsafe_cpu_and_1 +# define irqsafe_cpu_and_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=) +# endif +# ifndef irqsafe_cpu_and_2 +# define irqsafe_cpu_and_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=) +# endif +# ifndef irqsafe_cpu_and_4 +# define irqsafe_cpu_and_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=) +# endif +# ifndef irqsafe_cpu_and_8 +# define irqsafe_cpu_and_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=) +# endif +# define irqsafe_cpu_and(pcp, val) __size_call(irqsafe_cpu_and_, (val)) +#endif + +#ifndef irqsafe_cpu_or +# ifndef irqsafe_cpu_or_1 +# define irqsafe_cpu_or_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=) +# endif +# ifndef irqsafe_cpu_or_2 +# define irqsafe_cpu_or_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=) +# endif +# ifndef irqsafe_cpu_or_4 +# define irqsafe_cpu_or_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=) +# endif +# ifndef irqsafe_cpu_or_8 +# define irqsafe_cpu_or_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=) +# endif +# define irqsafe_cpu_or(pcp, val) __size_call(irqsafe_cpu_or_, (val)) +#endif + +#ifndef irqsafe_cpu_xor +# ifndef irqsafe_cpu_xor_1 +# define irqsafe_cpu_xor_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=) +# endif +# ifndef irqsafe_cpu_xor_2 +# define irqsafe_cpu_xor_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=) +# endif +# ifndef irqsafe_cpu_xor_4 +# define irqsafe_cpu_xor_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=) +# endif +# ifndef irqsafe_cpu_xor_8 +# define irqsafe_cpu_xor_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=) +# endif +# define irqsafe_cpu_xor(pcp, val) __size_call(irqsafe_cpu_xor_, (val)) +#endif + #endif /* __LINUX_PERCPU_H */ -- cgit v1.2.3 From 4eb41d10c7ab419a1408bed2e63a9c0fdfa38844 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Sat, 3 Oct 2009 19:48:22 +0900 Subject: this_cpu: Use this_cpu operations for SNMP statistics SNMP statistic macros can be signficantly simplified. This will also reduce code size if the arch supports these operations in hardware. Acked-by: Tejun Heo Signed-off-by: Christoph Lameter Signed-off-by: Tejun Heo --- include/net/snmp.h | 50 ++++++++++++++++++-------------------------------- 1 file changed, 18 insertions(+), 32 deletions(-) (limited to 'include') diff --git a/include/net/snmp.h b/include/net/snmp.h index 8c842e06bec8..f0d756f2ac99 100644 --- a/include/net/snmp.h +++ b/include/net/snmp.h @@ -136,45 +136,31 @@ struct linux_xfrm_mib { #define SNMP_STAT_BHPTR(name) (name[0]) #define SNMP_STAT_USRPTR(name) (name[1]) -#define SNMP_INC_STATS_BH(mib, field) \ - (per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field]++) -#define SNMP_INC_STATS_USER(mib, field) \ - do { \ - per_cpu_ptr(mib[1], get_cpu())->mibs[field]++; \ - put_cpu(); \ - } while (0) -#define SNMP_INC_STATS(mib, field) \ - do { \ - per_cpu_ptr(mib[!in_softirq()], get_cpu())->mibs[field]++; \ - put_cpu(); \ - } while (0) -#define SNMP_DEC_STATS(mib, field) \ - do { \ - per_cpu_ptr(mib[!in_softirq()], get_cpu())->mibs[field]--; \ - put_cpu(); \ - } while (0) -#define SNMP_ADD_STATS(mib, field, addend) \ - do { \ - per_cpu_ptr(mib[!in_softirq()], get_cpu())->mibs[field] += addend; \ - put_cpu(); \ - } while (0) -#define SNMP_ADD_STATS_BH(mib, field, addend) \ - (per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field] += addend) -#define SNMP_ADD_STATS_USER(mib, field, addend) \ - do { \ - per_cpu_ptr(mib[1], get_cpu())->mibs[field] += addend; \ - put_cpu(); \ - } while (0) +#define SNMP_INC_STATS_BH(mib, field) \ + __this_cpu_inc(mib[0]->mibs[field]) +#define SNMP_INC_STATS_USER(mib, field) \ + this_cpu_inc(mib[1]->mibs[field]) +#define SNMP_INC_STATS(mib, field) \ + this_cpu_inc(mib[!in_softirq()]->mibs[field]) +#define SNMP_DEC_STATS(mib, field) \ + this_cpu_dec(mib[!in_softirq()]->mibs[field]) +#define SNMP_ADD_STATS_BH(mib, field, addend) \ + __this_cpu_add(mib[0]->mibs[field], addend) +#define SNMP_ADD_STATS_USER(mib, field, addend) \ + this_cpu_add(mib[1]->mibs[field], addend) #define SNMP_UPD_PO_STATS(mib, basefield, addend) \ do { \ - __typeof__(mib[0]) ptr = per_cpu_ptr(mib[!in_softirq()], get_cpu());\ + __typeof__(mib[0]) ptr; \ + preempt_disable(); \ + ptr = this_cpu_ptr((mib)[!in_softirq()]); \ ptr->mibs[basefield##PKTS]++; \ ptr->mibs[basefield##OCTETS] += addend;\ - put_cpu(); \ + preempt_enable(); \ } while (0) #define SNMP_UPD_PO_STATS_BH(mib, basefield, addend) \ do { \ - __typeof__(mib[0]) ptr = per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id());\ + __typeof__(mib[0]) ptr = \ + __this_cpu_ptr((mib)[!in_softirq()]); \ ptr->mibs[basefield##PKTS]++; \ ptr->mibs[basefield##OCTETS] += addend;\ } while (0) -- cgit v1.2.3 From 4ea7334b6de818b0123fa4be32af4cb8ac65174c Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Sat, 3 Oct 2009 19:48:22 +0900 Subject: this_cpu: Use this_cpu ops for network statistics Acked-by: Tejun Heo Acked-by: David Miller Signed-off-by: Christoph Lameter Signed-off-by: Tejun Heo --- include/net/neighbour.h | 7 +------ include/net/netfilter/nf_conntrack.h | 4 ++-- 2 files changed, 3 insertions(+), 8 deletions(-) (limited to 'include') diff --git a/include/net/neighbour.h b/include/net/neighbour.h index 3817fda82a80..f28403ff7648 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -90,12 +90,7 @@ struct neigh_statistics unsigned long unres_discards; /* number of unresolved drops */ }; -#define NEIGH_CACHE_STAT_INC(tbl, field) \ - do { \ - preempt_disable(); \ - (per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \ - preempt_enable(); \ - } while (0) +#define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field) struct neighbour { diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h index cbdd6284996d..dde549779e42 100644 --- a/include/net/netfilter/nf_conntrack.h +++ b/include/net/netfilter/nf_conntrack.h @@ -295,11 +295,11 @@ extern unsigned int nf_conntrack_htable_size; extern unsigned int nf_conntrack_max; #define NF_CT_STAT_INC(net, count) \ - (per_cpu_ptr((net)->ct.stat, raw_smp_processor_id())->count++) + __this_cpu_inc((net)->ct.stat->count) #define NF_CT_STAT_INC_ATOMIC(net, count) \ do { \ local_bh_disable(); \ - per_cpu_ptr((net)->ct.stat, raw_smp_processor_id())->count++; \ + __this_cpu_inc((net)->ct.stat->count); \ local_bh_enable(); \ } while (0) -- cgit v1.2.3 From 4dac3e98840f11bb2d8d52fd375150c7c1912117 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Sat, 3 Oct 2009 19:48:23 +0900 Subject: this_cpu: Use this_cpu ops for VM statistics Using per cpu atomics for the vm statistics reduces their overhead. And in the case of x86 we are guaranteed that they will never race even in the lax form used for vm statistics. Acked-by: Tejun Heo Signed-off-by: Christoph Lameter Signed-off-by: Tejun Heo --- include/linux/vmstat.h | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index 2d0f222388a8..d85889710f9b 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -76,24 +76,22 @@ DECLARE_PER_CPU(struct vm_event_state, vm_event_states); static inline void __count_vm_event(enum vm_event_item item) { - __get_cpu_var(vm_event_states).event[item]++; + __this_cpu_inc(per_cpu_var(vm_event_states).event[item]); } static inline void count_vm_event(enum vm_event_item item) { - get_cpu_var(vm_event_states).event[item]++; - put_cpu(); + this_cpu_inc(per_cpu_var(vm_event_states).event[item]); } static inline void __count_vm_events(enum vm_event_item item, long delta) { - __get_cpu_var(vm_event_states).event[item] += delta; + __this_cpu_add(per_cpu_var(vm_event_states).event[item], delta); } static inline void count_vm_events(enum vm_event_item item, long delta) { - get_cpu_var(vm_event_states).event[item] += delta; - put_cpu(); + this_cpu_add(per_cpu_var(vm_event_states).event[item], delta); } extern void all_vm_events(unsigned long *); -- cgit v1.2.3 From 64ef291f46d795917f32a0f5975e2b76f6fe206a Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 29 Oct 2009 22:34:12 +0900 Subject: percpu: make alloc_percpu() handle array types alloc_percpu() couldn't handle array types like "int [100]" due to the way return type was casted. Fix it by using typeof() instead. Signed-off-by: Tejun Heo Reviewed-by: Frederic Weisbecker Reviewed-by: Christoph Lameter --- include/linux/percpu.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 3d9ba92b104f..519d6876590f 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -164,8 +164,8 @@ static inline void *pcpu_lpage_remapped(void *kaddr) #endif /* CONFIG_SMP */ -#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \ - __alignof__(type)) +#define alloc_percpu(type) \ + (typeof(type) *)__alloc_percpu(sizeof(type), __alignof__(type)) /* * Optional methods for optimized non-lvalue per-cpu variable access. -- cgit v1.2.3 From 0f5e4816dbf38ce9488e611ca2296925c1e90d5e Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 29 Oct 2009 22:34:12 +0900 Subject: percpu: remove some sparse warnings Make the following changes to remove some sparse warnings. * Make DEFINE_PER_CPU_SECTION() declare __pcpu_unique_* before defining it. * Annotate pcpu_extend_area_map() that it is entered with pcpu_lock held, releases it and then reacquires it. * Make percpu related macros use unique nested variable names. * While at it, add pcpu prefix to __size_call[_return]() macros as to-be-implemented sparse annotations will add percpu specific stuff to these macros. Signed-off-by: Tejun Heo Reviewed-by: Christoph Lameter Cc: Rusty Russell --- include/linux/percpu-defs.h | 1 + include/linux/percpu.h | 48 ++++++++++++++++++++++----------------------- 2 files changed, 25 insertions(+), 24 deletions(-) (limited to 'include') diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index 9bd03193ecd4..5a5d6ce4bd55 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -60,6 +60,7 @@ #define DEFINE_PER_CPU_SECTION(type, name, sec) \ __PCPU_DUMMY_ATTRS char __pcpu_scope_##name; \ + extern __PCPU_DUMMY_ATTRS char __pcpu_unique_##name; \ __PCPU_DUMMY_ATTRS char __pcpu_unique_##name; \ __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES __weak \ __typeof__(type) per_cpu__##name diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 519d6876590f..522f421ec213 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -226,20 +226,20 @@ do { \ extern void __bad_size_call_parameter(void); -#define __size_call_return(stem, variable) \ -({ typeof(variable) ret__; \ +#define __pcpu_size_call_return(stem, variable) \ +({ typeof(variable) pscr_ret__; \ switch(sizeof(variable)) { \ - case 1: ret__ = stem##1(variable);break; \ - case 2: ret__ = stem##2(variable);break; \ - case 4: ret__ = stem##4(variable);break; \ - case 8: ret__ = stem##8(variable);break; \ + case 1: pscr_ret__ = stem##1(variable);break; \ + case 2: pscr_ret__ = stem##2(variable);break; \ + case 4: pscr_ret__ = stem##4(variable);break; \ + case 8: pscr_ret__ = stem##8(variable);break; \ default: \ __bad_size_call_parameter();break; \ } \ - ret__; \ + pscr_ret__; \ }) -#define __size_call(stem, variable, ...) \ +#define __pcpu_size_call(stem, variable, ...) \ do { \ switch(sizeof(variable)) { \ case 1: stem##1(variable, __VA_ARGS__);break; \ @@ -299,7 +299,7 @@ do { \ # ifndef this_cpu_read_8 # define this_cpu_read_8(pcp) _this_cpu_generic_read(pcp) # endif -# define this_cpu_read(pcp) __size_call_return(this_cpu_read_, (pcp)) +# define this_cpu_read(pcp) __pcpu_size_call_return(this_cpu_read_, (pcp)) #endif #define _this_cpu_generic_to_op(pcp, val, op) \ @@ -322,7 +322,7 @@ do { \ # ifndef this_cpu_write_8 # define this_cpu_write_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), =) # endif -# define this_cpu_write(pcp, val) __size_call(this_cpu_write_, (pcp), (val)) +# define this_cpu_write(pcp, val) __pcpu_size_call(this_cpu_write_, (pcp), (val)) #endif #ifndef this_cpu_add @@ -338,7 +338,7 @@ do { \ # ifndef this_cpu_add_8 # define this_cpu_add_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=) # endif -# define this_cpu_add(pcp, val) __size_call(this_cpu_add_, (pcp), (val)) +# define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, (pcp), (val)) #endif #ifndef this_cpu_sub @@ -366,7 +366,7 @@ do { \ # ifndef this_cpu_and_8 # define this_cpu_and_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=) # endif -# define this_cpu_and(pcp, val) __size_call(this_cpu_and_, (pcp), (val)) +# define this_cpu_and(pcp, val) __pcpu_size_call(this_cpu_and_, (pcp), (val)) #endif #ifndef this_cpu_or @@ -382,7 +382,7 @@ do { \ # ifndef this_cpu_or_8 # define this_cpu_or_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=) # endif -# define this_cpu_or(pcp, val) __size_call(this_cpu_or_, (pcp), (val)) +# define this_cpu_or(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val)) #endif #ifndef this_cpu_xor @@ -398,7 +398,7 @@ do { \ # ifndef this_cpu_xor_8 # define this_cpu_xor_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=) # endif -# define this_cpu_xor(pcp, val) __size_call(this_cpu_or_, (pcp), (val)) +# define this_cpu_xor(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val)) #endif /* @@ -428,7 +428,7 @@ do { \ # ifndef __this_cpu_read_8 # define __this_cpu_read_8(pcp) (*__this_cpu_ptr(&(pcp))) # endif -# define __this_cpu_read(pcp) __size_call_return(__this_cpu_read_, (pcp)) +# define __this_cpu_read(pcp) __pcpu_size_call_return(__this_cpu_read_, (pcp)) #endif #define __this_cpu_generic_to_op(pcp, val, op) \ @@ -449,7 +449,7 @@ do { \ # ifndef __this_cpu_write_8 # define __this_cpu_write_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), =) # endif -# define __this_cpu_write(pcp, val) __size_call(__this_cpu_write_, (pcp), (val)) +# define __this_cpu_write(pcp, val) __pcpu_size_call(__this_cpu_write_, (pcp), (val)) #endif #ifndef __this_cpu_add @@ -465,7 +465,7 @@ do { \ # ifndef __this_cpu_add_8 # define __this_cpu_add_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=) # endif -# define __this_cpu_add(pcp, val) __size_call(__this_cpu_add_, (pcp), (val)) +# define __this_cpu_add(pcp, val) __pcpu_size_call(__this_cpu_add_, (pcp), (val)) #endif #ifndef __this_cpu_sub @@ -493,7 +493,7 @@ do { \ # ifndef __this_cpu_and_8 # define __this_cpu_and_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=) # endif -# define __this_cpu_and(pcp, val) __size_call(__this_cpu_and_, (pcp), (val)) +# define __this_cpu_and(pcp, val) __pcpu_size_call(__this_cpu_and_, (pcp), (val)) #endif #ifndef __this_cpu_or @@ -509,7 +509,7 @@ do { \ # ifndef __this_cpu_or_8 # define __this_cpu_or_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=) # endif -# define __this_cpu_or(pcp, val) __size_call(__this_cpu_or_, (pcp), (val)) +# define __this_cpu_or(pcp, val) __pcpu_size_call(__this_cpu_or_, (pcp), (val)) #endif #ifndef __this_cpu_xor @@ -525,7 +525,7 @@ do { \ # ifndef __this_cpu_xor_8 # define __this_cpu_xor_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=) # endif -# define __this_cpu_xor(pcp, val) __size_call(__this_cpu_xor_, (pcp), (val)) +# define __this_cpu_xor(pcp, val) __pcpu_size_call(__this_cpu_xor_, (pcp), (val)) #endif /* @@ -556,7 +556,7 @@ do { \ # ifndef irqsafe_cpu_add_8 # define irqsafe_cpu_add_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=) # endif -# define irqsafe_cpu_add(pcp, val) __size_call(irqsafe_cpu_add_, (pcp), (val)) +# define irqsafe_cpu_add(pcp, val) __pcpu_size_call(irqsafe_cpu_add_, (pcp), (val)) #endif #ifndef irqsafe_cpu_sub @@ -584,7 +584,7 @@ do { \ # ifndef irqsafe_cpu_and_8 # define irqsafe_cpu_and_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=) # endif -# define irqsafe_cpu_and(pcp, val) __size_call(irqsafe_cpu_and_, (val)) +# define irqsafe_cpu_and(pcp, val) __pcpu_size_call(irqsafe_cpu_and_, (val)) #endif #ifndef irqsafe_cpu_or @@ -600,7 +600,7 @@ do { \ # ifndef irqsafe_cpu_or_8 # define irqsafe_cpu_or_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=) # endif -# define irqsafe_cpu_or(pcp, val) __size_call(irqsafe_cpu_or_, (val)) +# define irqsafe_cpu_or(pcp, val) __pcpu_size_call(irqsafe_cpu_or_, (val)) #endif #ifndef irqsafe_cpu_xor @@ -616,7 +616,7 @@ do { \ # ifndef irqsafe_cpu_xor_8 # define irqsafe_cpu_xor_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=) # endif -# define irqsafe_cpu_xor(pcp, val) __size_call(irqsafe_cpu_xor_, (val)) +# define irqsafe_cpu_xor(pcp, val) __pcpu_size_call(irqsafe_cpu_xor_, (val)) #endif #endif /* __LINUX_PERCPU_H */ -- cgit v1.2.3 From 3b034b0d084221596bf35c8d893e1d4d5477b9cc Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Tue, 24 Nov 2009 15:50:03 +0900 Subject: percpu: Fix kdump failure if booted with percpu_alloc=page o kdump functionality reserves a per cpu area at boot time and exports the physical address of that area to user space through sys interface. This area stores some dump related information like cpu register states etc at the time of crash. o We were assuming that per cpu area always come from linearly mapped meory region and using __pa() to determine physical address. With percpu_alloc=page, per cpu area can come from vmalloc region also and __pa() breaks. o This patch implments a new function to convert per cpu address to physical address. Before the patch, crash_notes addresses looked as follows. cpu0 60fffff49800 cpu1 60fffff60800 cpu2 60fffff77800 These are bogus phsyical addresses. After the patch, address are following. cpu0 13eb44000 cpu1 13eb43000 cpu2 13eb42000 cpu3 13eb41000 These look fine. I got 4G of memory and /proc/iomem tell me following. 100000000-13fffffff : System RAM tj: * added missing asm/io.h include reported by Stephen Rothwell * repositioned per_cpu_ptr_phys() in percpu.c and added comment. Signed-off-by: Vivek Goyal Signed-off-by: Tejun Heo Cc: Stephen Rothwell --- include/linux/percpu.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 878836ca999c..6ac984fa34f8 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -154,6 +154,7 @@ struct percpu_data { extern void *__alloc_percpu(size_t size, size_t align); extern void free_percpu(void *__pdata); +extern phys_addr_t per_cpu_ptr_to_phys(void *addr); #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA extern void __init setup_per_cpu_areas(void); -- cgit v1.2.3 From ee0a6efc1897ef817e177e669f5c5d211194df24 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 2 Dec 2009 08:36:58 +0900 Subject: percpu: add missing per_cpu_ptr_to_phys() definition for UP Commit 3b034b0d084221596bf35c8d893e1d4d5477b9cc implemented per_cpu_ptr_to_phys() but forgot to add UP definition. Add UP definition which is simple wrapper around __pa(). Signed-off-by: Tejun Heo Cc: Vivek Goyal Reported-by: Randy Dunlap --- include/linux/percpu.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include') diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 6ac984fa34f8..8e4ead6435fb 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -180,6 +180,11 @@ static inline void free_percpu(void *p) kfree(p); } +static inline phys_addr_t per_cpu_ptr_to_phys(void *addr) +{ + return __pa(addr); +} + static inline void __init setup_per_cpu_areas(void) { } static inline void *pcpu_lpage_remapped(void *kaddr) -- cgit v1.2.3