Commit Graph

2 Commits

Author SHA1 Message Date
Heiko Carstens
a4d9b97cc3 s390/cio: use basic blocks for i/o inline assemblies
Use only simple inline assemblies which consist of a single basic
block if the register asm construct is being used.

Otherwise gcc would generate broken code if the compiler option
--sanitize-coverage=trace-pc would be used.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28 09:32:34 +02:00
Peter Oberparleiter
11b64c8acc s390/cio: Change I/O instructions from inline to normal functions
Adding tracepoints to inline functions adds tracepoint invocation code
for each instance where the function is inlined. The resulting increase
in kernel code size can have negative impact:
 - More cache misses in instruction cache
 - Reduced amount of DMA-capable memory

Therefore change all functions implementing I/O instructions from inline
to normal functions.

Bloat-o-meter summary after change (using performance_defconfig):

  add/remove: 24/2 grow/shrink: 4/39 up/down: 2205/-4858 (-2653)

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-12-18 14:59:37 +01:00