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authorFrank Pavlic <pavlic@de.ibm.com>2006-01-06 00:19:20 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-06 08:33:51 -0800
commit8129ee164267dc030b8e1d541ee3643c0b9f2fa1 (patch)
treeca477e575a9098e637411332a8d354477143eff4 /arch
parent05f29fcdb0c6c99484c8bea5e244fe2f4edc9337 (diff)
[PATCH] s390: qdio V=V pass-through
New feature V=V qdio pass-through. QDIO and HiperSockets processing in z/VM V=V guest environments (as well as V=R with z/VM running in LPAR mode) requires shadowing of all QDIO architecture queue elements. Especially the shadowing of SBALs and SLSBs structures in the hypervisor, and the need to issue SIGA SYNC operations to observe state changes, eventually causes significant CPU processing overhead in the hypervisor. The QDIO pass-through support for V=V guests avoids the shadowing of SBALs and SLSBs. This significantly reduces the hypervisor overhead for QDIO based I/O. Signed-off-by: Frank Pavlic <pavlic@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/Kconfig7
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 477ac2758bd..1846fbfd6bf 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -240,8 +240,8 @@ config MACHCHK_WARNING
config QDIO
tristate "QDIO support"
---help---
- This driver provides the Queued Direct I/O base support for the
- IBM S/390 (G5 and G6) and eServer zSeries (z800, z890, z900 and z990).
+ This driver provides the Queued Direct I/O base support for
+ IBM mainframes.
For details please refer to the documentation provided by IBM at
<http://www10.software.ibm.com/developerworks/opensource/linux390>
@@ -263,7 +263,8 @@ config QDIO_DEBUG
bool "Extended debugging information"
depends on QDIO
help
- Say Y here to get extended debugging output in /proc/s390dbf/qdio...
+ Say Y here to get extended debugging output in
+ /sys/kernel/debug/s390dbf/qdio...
Warning: this option reduces the performance of the QDIO module.
If unsure, say N.