The patch titled
Revert "local_t Documentation update"
has been removed from the -mm tree. Its filename was
revert-local_t-documentation-update.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: Revert "local_t Documentation update"
From: Li Zefan <lizf@xxxxxxxxxxxxxx>
This reverts commit e1265205c0ee3919c3f2c750662630154c8faab2.
It's a duplicate commit of commit 74beb9db77930be476b267ec8518a642f39a04bf,
resulting in a duplicate section.
Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/local_ops.txt | 23 -----------------------
1 file changed, 23 deletions(-)
diff -puN Documentation/local_ops.txt~revert-local_t-documentation-update Documentation/local_ops.txt
--- a/Documentation/local_ops.txt~revert-local_t-documentation-update
+++ a/Documentation/local_ops.txt
@@ -68,29 +68,6 @@ typedef struct { atomic_long_t a; } loca
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- synchronization is done by the writer CPU, an outdated copy of the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>
_
Patches currently in -mm which might be from lizf@xxxxxxxxxxxxxx are
origin.patch
git-powerpc.patch
git-drm.patch
git-hid.patch
git-net.patch
git-netdev-all.patch
clocksource-remove-redundant-code.patch
clockevent-simplify-list-operations.patch
timekeeping-rename-timekeeping_is_continuous-to-timekeeping_valid_for_hres.patch
time-fix-typo-in-comments.patch
time-delete-comments-that-refer-to-noexistent-symbols.patch
-
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