linux/arch/s390
Christian Borntraeger 8107d8296b [S390] fix/cleanup sched_clock
CONFIG_PRINTK_TIME reveals that sched_clock has a wrong offset during boot:
..
[    0.000000]   Movable zone: 0 pages used for memmap
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 775679
[    0.000000] Kernel command line: dasd=4b6c root=/dev/dasda1 ro noinitrd
[    0.000000] PID hash table entries: 4096 (order: 12, 32768 bytes)
[6920575.975232] console [ttyS0] enabled
[6920575.987586] Dentry cache hash table entries: 524288 (order: 10, 4194304 bytes)
[6920575.991404] Inode-cache hash table entries: 262144 (order: 9, 2097152 bytes)
..

The s390 implementation of sched_clock uses the store clock instruction and
subtracts jiffies_timer_cc.
jiffies_timer_cc is a local variable in arch/s390/kernel/time.c and only used
for sched_clock and monotonic clock. For historical reasons there is an offset
on that value. With todays code this offset is unnecessary. By removing that
offset we can get a sched_clock which returns the nanoseconds after time_init.
This improves CONFIG_PRINTK_TIME.

Since sched_clock is the only user, I have also renamed jiffies_timer_cc to
sched_clock_base_cc. In addition, the local variable init_timer_cc is redundant
and can be romved as well.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-11-27 11:06:57 +01:00
..
appldata [S390] appldata: unsigned ops->size cannot be negative 2008-10-28 11:12:04 +01:00
boot [PATCH] use ${CROSS_COMPILE}installkernel in arch/*/boot/install.sh 2005-06-23 09:45:07 -07:00
crypto Merge branch 'bkl-removal' of git://git.lwn.net/linux-2.6 2008-07-14 14:48:31 -07:00
hypfs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
include/asm [S390] fix system call parameter functions. 2008-11-27 11:06:56 +01:00
kernel [S390] fix/cleanup sched_clock 2008-11-27 11:06:57 +01:00
kvm KVM: s390: Make facility bits future-proof 2008-10-15 10:15:24 +02:00
lib [S390] Move private simple udelay function to arch/s390/lib/delay.c. 2008-10-10 21:33:58 +02:00
math-emu [S390] remove -traditional 2008-04-30 13:38:44 +02:00
mm [S390] pgtables: Fix race in enable_sie vs. page table ops 2008-10-28 11:12:03 +01:00
oprofile Combine instrumentation menus in kernel/Kconfig.instrumentation 2007-10-19 11:53:54 -07:00
defconfig [S390] Update default configuration. 2008-08-21 19:46:42 +02:00
Kconfig [S390] No more 4kb stacks. 2008-10-28 11:12:06 +01:00
Kconfig.debug [S390] DEBUG_PAGEALLOC support for s390. 2008-02-05 16:50:54 +01:00
Makefile KVM: s390: arch backend for the kvm kernel module 2008-04-27 12:00:42 +03:00