Commit Graph

4 Commits

Author SHA1 Message Date
Hendrik Brueckner 157a1a27d5 [S390] vdso: use ntp adjusted clock multiplier
Commit "timekeeping: Fix clock_gettime vsyscall time warp" (0696b711e)
introduced the new parameter "mult" to update_vsyscall(). This parameter
contains the internal NTP adjusted clock multiplier.

The s390x vdso did not use this adjusted multiplier.  Instead, it used
the constant clock multiplier for gettimeofday() and clock_gettime()
variants.  This may result in observable time warps as explained in
commit 0696b711e.

Make the NTP adjusted clock multiplier available to the s390x vdso
implementation and use it for time calculations.

Cc: <stable@kernel.org>
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-04-22 17:17:19 +02:00
Martin Schwidefsky 13c6680acb [S390] correct vdso version string
The glibc vdso code for s390 uses the version string 2.6.29, the
kernel uses the version string 2.6.26. No wonder the vdso code
is never used. The first kernel version to contain the vdso code
is 2.6.29 which makes this the correct version.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26 22:37:33 +01:00
Martin Schwidefsky c742b31c03 [PATCH] fast vdso implementation for CLOCK_THREAD_CPUTIME_ID
The extract cpu time instruction (ectg) instruction allows the user
process to get the current thread cputime without calling into the
kernel. The code that uses the instruction needs to switch to the
access registers mode to get access to the per-cpu info page that
contains the two base values that are needed to calculate the current
cputime from the CPU timer with the ectg instruction.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 15:11:49 +01:00
Martin Schwidefsky b020632e40 [S390] introduce vdso on s390
Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for
CLOCK_REALTIME/CLOCK_MONOTONIC.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-25 13:38:55 +01:00