* [PATCH] Documentation: scheduler: sched-arch: remove __ARCH_WANT_UNLOCKED_CTXSW macro
@ 2017-05-17 15:20 Karim Eshapa
0 siblings, 0 replies; only message in thread
From: Karim Eshapa @ 2017-05-17 15:20 UTC (permalink / raw)
To: corbet; +Cc: linux-doc, linux-kernel, Karim Eshapa
remove __ARCH_WANT_UNLOCKED_CTXSW macro because it's no longer
exist after 3.17.8 kernel release.
Signed-off-by: Karim Eshapa <karim.eshapa@gmail.com>
---
Documentation/scheduler/sched-arch.txt | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/Documentation/scheduler/sched-arch.txt b/Documentation/scheduler/sched-arch.txt
index a2f27bb..36ed0b4 100644
--- a/Documentation/scheduler/sched-arch.txt
+++ b/Documentation/scheduler/sched-arch.txt
@@ -6,16 +6,11 @@ Context switch
==============
1. Runqueue locking
By default, the switch_to arch function is called with the runqueue
-locked. This is usually not a problem unless switch_to may need to
-take the runqueue lock. This is usually due to a wake up operation in
-the context switch. See arch/ia64/include/asm/switch_to.h for an example.
-
-To request the scheduler call switch_to with the runqueue unlocked,
-you must `#define __ARCH_WANT_UNLOCKED_CTXSW` in a header file
-(typically the one where switch_to is defined).
-
-Unlocked context switches introduce only a very minor performance
-penalty to the core scheduler implementation in the CONFIG_SMP case.
+locked. This is usually due to a wake up operation in the context
+switch.The schedular call switch_to became with runqueue unlocked
+such that use rq_unpin_lock(), spin_release() that warn for locking
+bugs (lock inversion, circular lock dependencies,..) and release
+lockdep respectively.
CPU idle
========
--
2.7.4
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