[S390] zero page cache synonyms
authorMartin Schwidefsky <schwidefsky@de.ibm.com>
Mon, 25 Oct 2010 14:10:07 +0000 (16:10 +0200)
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>
Mon, 25 Oct 2010 14:10:14 +0000 (16:10 +0200)
commit238ec4efeee4461d5cff2ed3e5a15a3ab850959b
treed9efb4be22cc550c7559c29627a48d66413c645a
parent229aebb873e29726b91e076161649cf45154b0bf
[S390] zero page cache synonyms

If the zero page is mapped to virtual user space addresses that differ
only in bit 2^12 or 2^13 we get L1 cache synonyms which can affect
performance. Follow the mips model and use multiple zero pages to avoid
the synonyms.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/include/asm/pgtable.h
arch/s390/mm/init.c