lkml.org 
[lkml]   [2010]   [Dec]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[cpuops UPDATED 1/9] percpu: Generic support for this_cpu_add,sub,dec,inc_return
    From: Christoph Lameter <cl@linux.com>
    Subject: percpu: Generic support for this_cpu_add, sub, dec, inc_return

    Introduce generic support for this_cpu_add_return etc.

    The fallback is to realize these operations with simpler __this_cpu_ops.

    tj: - Reformatted __cpu_size_call_return2() to make it more consistent
    with its neighbors.

    - Dropped unnecessary temp variable ret__ from
    __this_cpu_generic_add_return().

    Reviewed-by: Tejun Heo <tj@kernel.org>
    Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
    Signed-off-by: Christoph Lameter <cl@linux.com>
    Signed-off-by: Tejun Heo <tj@kernel.org>
    ---
    I updated it a bit. If you don't like it, please scream.

    Thanks.

    include/linux/percpu.h | 71 +++++++++++++++++++++++++++++++++++++++++++++++++
    1 file changed, 71 insertions(+)

    Index: percpu/include/linux/percpu.h
    ===================================================================
    --- percpu.orig/include/linux/percpu.h
    +++ percpu/include/linux/percpu.h
    @@ -240,6 +240,21 @@ extern void __bad_size_call_parameter(vo
    pscr_ret__; \
    })

    +#define __pcpu_size_call_return2(stem, variable, ...) \
    +({ \
    + typeof(variable) pscr2_ret__; \
    + __verify_pcpu_ptr(&(variable)); \
    + switch(sizeof(variable)) { \
    + case 1: pscr2_ret__ = stem##1(variable, __VA_ARGS__); break; \
    + case 2: pscr2_ret__ = stem##2(variable, __VA_ARGS__); break; \
    + case 4: pscr2_ret__ = stem##4(variable, __VA_ARGS__); break; \
    + case 8: pscr2_ret__ = stem##8(variable, __VA_ARGS__); break; \
    + default: \
    + __bad_size_call_parameter(); break; \
    + } \
    + pscr2_ret__; \
    +})
    +
    #define __pcpu_size_call(stem, variable, ...) \
    do { \
    __verify_pcpu_ptr(&(variable)); \
    @@ -529,6 +544,62 @@ do { \
    # define __this_cpu_xor(pcp, val) __pcpu_size_call(__this_cpu_xor_, (pcp), (val))
    #endif

    +#define _this_cpu_generic_add_return(pcp, val) \
    +({ \
    + typeof(pcp) ret__; \
    + preempt_disable(); \
    + __this_cpu_add(pcp, val); \
    + ret__ = __this_cpu_read(pcp); \
    + preempt_enable(); \
    + ret__; \
    +})
    +
    +#ifndef this_cpu_add_return
    +# ifndef this_cpu_add_return_1
    +# define this_cpu_add_return_1(pcp, val) _this_cpu_generic_add_return(pcp, val)
    +# endif
    +# ifndef this_cpu_add_return_2
    +# define this_cpu_add_return_2(pcp, val) _this_cpu_generic_add_return(pcp, val)
    +# endif
    +# ifndef this_cpu_add_return_4
    +# define this_cpu_add_return_4(pcp, val) _this_cpu_generic_add_return(pcp, val)
    +# endif
    +# ifndef this_cpu_add_return_8
    +# define this_cpu_add_return_8(pcp, val) _this_cpu_generic_add_return(pcp, val)
    +# endif
    +# define this_cpu_add_return(pcp, val) __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
    +#endif
    +
    +#define this_cpu_sub_return(pcp, val) this_cpu_add_return(pcp, -(val))
    +#define this_cpu_inc_return(pcp) this_cpu_add_return(pcp, 1)
    +#define this_cpu_dec_return(pcp) this_cpu_add_return(pcp, -1)
    +
    +#define __this_cpu_generic_add_return(pcp, val) \
    +({ \
    + __this_cpu_add(pcp, val); \
    + __this_cpu_read(pcp); \
    +})
    +
    +#ifndef __this_cpu_add_return
    +# ifndef __this_cpu_add_return_1
    +# define __this_cpu_add_return_1(pcp, val) __this_cpu_generic_add_return(pcp, val)
    +# endif
    +# ifndef __this_cpu_add_return_2
    +# define __this_cpu_add_return_2(pcp, val) __this_cpu_generic_add_return(pcp, val)
    +# endif
    +# ifndef __this_cpu_add_return_4
    +# define __this_cpu_add_return_4(pcp, val) __this_cpu_generic_add_return(pcp, val)
    +# endif
    +# ifndef __this_cpu_add_return_8
    +# define __this_cpu_add_return_8(pcp, val) __this_cpu_generic_add_return(pcp, val)
    +# endif
    +# define __this_cpu_add_return(pcp, val) __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
    +#endif
    +
    +#define __this_cpu_sub_return(pcp, val) this_cpu_add_return(pcp, -(val))
    +#define __this_cpu_inc_return(pcp) this_cpu_add_return(pcp, 1)
    +#define __this_cpu_dec_return(pcp) this_cpu_add_return(pcp, -1)
    +
    /*
    * IRQ safe versions of the per cpu RMW operations. Note that these operations
    * are *not* safe against modification of the same variable from another

    \
     
     \ /
      Last update: 2010-12-08 17:19    [W:0.028 / U:185.828 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site