* Li Zefan ([EMAIL PROTECTED]) wrote:
> This reverts commit e1265205c0ee3919c3f2c750662630154c8faab2.
>
> It's a duplicate commit of commit 74beb9db77930be476b267ec8518a642f39a04bf,
> resulting in a duplicate section.
>
> Signed-off-by: Li Zefan <[EMAIL PROTECTED]>
>
Thanks, I guess it's been merged twice somehow :S
Acked-by: Mathieu Desnoyers <[EMAIL PROTECTED]>
> ---
> Documentation/local_ops.txt | 23 -----------------------
> 1 files changed, 0 insertions(+), 23 deletions(-)
>
> diff --git a/Documentation/local_ops.txt b/Documentation/local_ops.txt
> index 1a45f11..4269a11 100644
> --- a/Documentation/local_ops.txt
> +++ b/Documentation/local_ops.txt
> @@ -68,29 +68,6 @@ typedef struct { atomic_long_t a; } local_t;
> variable can be read when reading some _other_ cpu's variables.
>
>
> -* Rules to follow when using local atomic operations
> -
> -- Variables touched by local ops must be per cpu variables.
> -- _Only_ the CPU owner of these variables must write to them.
> -- This CPU can use local ops from any context (process, irq, softirq, nmi,
> ...)
> - to update its local_t variables.
> -- Preemption (or interrupts) must be disabled when using local ops in
> - process context to make sure the process won't be migrated to a
> - different CPU between getting the per-cpu variable and doing the
> - actual local op.
> -- When using local ops in interrupt context, no special care must be
> - taken on a mainline kernel, since they will run on the local CPU with
> - preemption already disabled. I suggest, however, to explicitly
> - disable preemption anyway to make sure it will still work correctly on
> - -rt kernels.
> -- Reading the local cpu variable will provide the current copy of the
> - variable.
> -- Reads of these variables can be done from any CPU, because updates to
> - "long", aligned, variables are always atomic. Since no memory
> - synchronization is done by the writer CPU, an outdated copy of the
> - variable can be read when reading some _other_ cpu's variables.
> -
> -
> * How to use local atomic operations
>
> #include <linux/percpu.h>
> --
> 1.5.3.rc7
>
--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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