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Revision 9d514262425691dddf942edea8bc9919e66fe140 authored by Wanpeng Li on 13 May 2015, 06:01:03 UTC, committed by Ingo Molnar on 19 June 2015, 08:06:46 UTC 
sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target
 
This patch adds a check that prevents futile attempts to move DL tasks
to a CPU with active tasks of equal or earlier deadline. The same
behavior as commit 80e3d87b2c55 ("sched/rt: Reduce rq lock contention
by eliminating locking of non-feasible target") for rt class.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431496867-4194-3-git-send-email-wanpeng.li@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 parent a6c0e74
Raw File
bad_memory.txt 
March 2008
Jan-Simon Moeller, dl9pf@gmx.de


How to deal with bad memory e.g. reported by memtest86+ ?
#########################################################

There are three possibilities I know of:

1) Reinsert/swap the memory modules

2) Buy new modules (best!) or try to exchange the memory
   if you have spare-parts

3) Use BadRAM or memmap

This Howto is about number 3) .


BadRAM
######
BadRAM is the actively developed and available as kernel-patch
here:  http://rick.vanrein.org/linux/badram/

For more details see the BadRAM documentation.

memmap
######

memmap is already in the kernel and usable as kernel-parameter at
boot-time.  Its syntax is slightly strange and you may need to
calculate the values by yourself!

Syntax to exclude a memory area (see kernel-parameters.txt for details):
memmap=<size>$<address>

Example: memtest86+ reported here errors at address 0x18691458, 0x18698424 and
         some others. All had 0x1869xxxx in common, so I chose a pattern of
         0x18690000,0xffff0000.

With the numbers of the example above:
memmap=64K$0x18690000
 or
memmap=0x10000$0x18690000
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