linux/drivers/s390/block
Stefan Weinhuber 4fa52aa7a8 [S390] dasd: add enhanced DASD statistics interface
This patch extends the DASD statistics to allow for a more detailed
analysis of DASD I/O operations. In particular we want the statistics
to provide answers to the following questions:
- How many requests used a PAV alias?
- How many requests used High Performance FICON?
- How do read request perform versus write requests?

The existing DASD statistics interface has several shortcomings
- The interface for global data is a formatted text table in procfs
  (/proc/dasd/statistics). The layout is meant for human readers and
  is not to easy to parse. If values get to large for the table
  layout, they get scaled down.
- The statistics which are collected per block device can be
  accessed via an ioctl interface, which can only be extended by
  defining a new ioctl.
- There is no statistics interface for individual PAV base and alias
  devices.

To overcome theses shortcomings we create a new DASD statistics
interface in debugfs. This interface will contain one entry for global
data, one per DASD block device, and one per DASD base and alias
device. Each file contains the statistic data in easy to parse
name/value and name/array pairs. The existing interfaces will remain
functional, but they will not be extended.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-07-24 10:48:23 +02:00
..
dasd_3990_erp.c Fix common misspellings 2011-03-31 11:26:23 -03:00
dasd_alias.c [S390] get rid of unused variables 2011-05-23 10:24:28 +02:00
dasd_devmap.c [S390] dasd: fix race between open and offline 2011-04-20 10:15:43 +02:00
dasd_diag.c [S390] irq: merge irq.c and s390_ext.c 2011-05-26 09:48:24 +02:00
dasd_diag.h [S390] cleanup lowcore access from external interrupts 2010-10-25 16:10:19 +02:00
dasd_eckd.c [S390] dasd: fix return code handling 2011-05-23 10:24:28 +02:00
dasd_eckd.h [S390] dasd: Add support for raw ECKD access. 2011-01-05 12:47:30 +01:00
dasd_eer.c [S390] dasd: Improve handling of stolen DASD reservation 2011-01-05 12:47:30 +01:00
dasd_erp.c [S390] dasd: do path verification for paths added at runtime 2011-01-05 12:47:30 +01:00
dasd_fba.c [S390] ccw_driver: remove duplicate members 2011-03-23 10:15:59 +01:00
dasd_fba.h
dasd_genhd.c [S390] dasd: fix race between open and offline 2011-04-20 10:15:43 +02:00
dasd_int.h [S390] dasd: add enhanced DASD statistics interface 2011-07-24 10:48:23 +02:00
dasd_ioctl.c [S390] dasd: add enhanced DASD statistics interface 2011-07-24 10:48:23 +02:00
dasd_proc.c [S390] dasd: add enhanced DASD statistics interface 2011-07-24 10:48:23 +02:00
dasd.c [S390] dasd: add enhanced DASD statistics interface 2011-07-24 10:48:23 +02:00
dcssblk.c s390/block: kill the big kernel lock 2010-09-26 16:25:51 +02:00
Kconfig [S390] cleanup s390 Kconfig 2011-01-05 12:47:23 +01:00
Makefile [S390] dasd: add hyper PAV support to DASD device driver, part 1 2008-01-26 14:11:28 +01:00
xpram.c [S390] xpram: remove __initdata attribute from module parameters 2011-03-03 17:56:14 +01:00