linux-toradex.git/kernel/time.c, branch v2.6.38.5

Kill off a bunch of warning: ‘inline’ is not at beginning of declaration

2010-11-28T22:08:04+00:00

These warnings are spewed during a build of a 'allnoconfig' kernel
(especially the ones from u64_stats_sync.h show up a lot) when building
with -Wextra (which I often do)..
They are
  a) annoying
  b) easy to get rid of.
This patch kills them off.

include/linux/u64_stats_sync.h:70:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:77:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:84:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:96:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:115:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:127:1: warning: ‘inline’ is not at beginning of declaration
kernel/time.c:241:1: warning: ‘inline’ is not at beginning of declaration
kernel/time.c:257:1: warning: ‘inline’ is not at beginning of declaration
kernel/perf_event.c:4513:1: warning: ‘inline’ is not at beginning of declaration
mm/page_alloc.c:4012:1: warning: ‘inline’ is not at beginning of declaration

Signed-off-by: Jesper Juhl 
Signed-off-by: Jiri Kosina

time: Kill off CONFIG_GENERIC_TIME

2010-07-27T10:40:54+00:00

Now that all arches have been converted over to use generic time via
clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME
config option and simplify the generic code.

Signed-off-by: John Stultz 
LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner

timekeeping: Fix timezone update

2010-05-24T09:50:38+00:00

commit 64ce4c2f (time: Clean up warp_clock()) breaks the timezone
update in a very subtle way. To avoid the direct access to timekeeping
internals it adds the timezone delta to the current time with
timespec_add_safe(). This works nicely when the timezone delta is > 0.
If timezone delta is < 0 then the wrap check in timespec_add_safe()
triggers and timespec_add_safe() returns TIME_MAX and screws up
timekeeping completely. 

The comment above timespec_add_safe() says:
    It's assumed that both values are valid (>= 0)

Add the timezone seconds adjustment directly.

Reported-by: Rafael J. Wysocki 
Tested-by: Rafael J. Wysocki 
Acked-by: John Stultz 
Signed-off-by: Thomas Gleixner

Merge branch 'linus' into timers/core

2010-05-10T12:20:42+00:00

Reason: Further posix_cpu_timer patches depend on mainline changes

Signed-off-by: Thomas Gleixner

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32+00:00

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn

time: Clean up warp_clock()

2010-03-12T21:40:42+00:00

warp_clock() currently accesses timekeeping internal state directly, which
is unnecessary.  Convert it to use the proper timekeeping interfaces.

Signed-off-by: John Stultz 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Thomas Gleixner

Revert "time: Remove xtime_cache"

2009-12-22T22:10:37+00:00

This reverts commit 7bc7d637452383d56ba4368d4336b0dde1bb476d, as
requested by John Stultz. Quoting John:

 "Petr Titěra reported an issue where he saw odd atime regressions with
  2.6.33 where there were a full second worth of nanoseconds in the
  nanoseconds field.

  He also reviewed the time code and narrowed down the problem: unhandled
  overflow of the nanosecond field caused by rounding up the
  sub-nanosecond accumulated time.

  Details:

   * At the end of update_wall_time(), we currently round up the
  sub-nanosecond portion of accumulated time when storing it into xtime.
  This was added to avoid time inconsistencies caused when the
  sub-nanosecond portion was truncated when storing into xtime.
  Unfortunately we don't handle the possible second overflow caused by
  that rounding.

   * Previously the xtime_cache code hid this overflow by normalizing the
  xtime value when storing into the xtime_cache.

   * We could try to handle the second overflow after the rounding up, but
  since this affects the timekeeping's internal state, this would further
  complicate the next accumulation cycle, causing small errors in ntp
  steering. As much as I'd like to get rid of it, the xtime_cache code is
  known to work.

   * The correct fix is really to include the sub-nanosecond portion in the
  timekeeping accessor function, so we don't need to round up at during
  accumulation. This would greatly simplify the accumulation code.
  Unfortunately, we can't do this safely until the last three
  non-GENERIC_TIME arches (sparc32, arm, cris) are converted  (those
  patches are in -mm) and we kill off the spots where arches set xtime
  directly. This is all 2.6.34 material, so I think reverting the
  xtime_cache change is the best approach for now.

  Many thanks to Petr for both reporting and finding the issue!"

Reported-by: Petr Titěra 
Requested-by: john stultz 
Cc: Ingo Molnar 
Signed-off-by: Linus Torvalds

Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-12-09T03:27:08+00:00

* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  timers, init: Limit the number of per cpu calibration bootup messages
  posix-cpu-timers: optimize and document timer_create callback
  clockevents: Add missing include to pacify sparse
  x86: vmiclock: Fix printk format
  x86: Fix printk format due to variable type change
  sparc: fix printk for change of variable type
  clocksource/events: Fix fallout of generic code changes
  nohz: Allow 32-bit machines to sleep for more than 2.15 seconds
  nohz: Track last do_timer() cpu
  nohz: Prevent clocksource wrapping during idle
  nohz: Type cast printk argument
  mips: Use generic mult/shift factor calculation for clocks
  clocksource: Provide a generic mult/shift factor calculation
  clockevents: Use u32 for mult and shift factors
  nohz: Introduce arch_needs_cpu
  nohz: Reuse ktime in sub-functions of tick_check_idle.
  time: Remove xtime_cache
  time: Implement logarithmic time accumulation

sched, time: Define nsecs_to_jiffies()

2009-11-26T11:59:20+00:00

Use of msecs_to_jiffies() for nsecs_to_cputime() have some
problems:

 - The type of msecs_to_jiffies()'s argument is unsigned int, so
   it cannot convert msecs greater than UINT_MAX = about 49.7 days.

 - msecs_to_jiffies() returns MAX_JIFFY_OFFSET if MSB of argument
   is set, assuming that input was negative value.  So it cannot
   convert msecs greater than INT_MAX = about 24.8 days too.

This patch defines a new function nsecs_to_jiffies() that can
deal greater values, and that can deal all incoming values as
unsigned.

Signed-off-by: Hidetoshi Seto 
Acked-by: Peter Zijlstra 
Cc: Stanislaw Gruszka 
Cc: Spencer Candland 
Cc: Oleg Nesterov 
Cc: Balbir Singh 
Cc: Amrico Wang 
Cc: Thomas Gleixner 
Cc: John Stultz 
LKML-Reference: <4B0E16E7.5070307@jp.fujitsu.com>
Signed-off-by: Ingo Molnar

time: Remove xtime_cache

2009-10-05T11:52:02+00:00

With the prior logarithmic time accumulation patch, xtime will now
always be within one "tick" of the current time, instead of
possibly half a second off.

This removes the need for the xtime_cache value, which always
stored the time at the last interrupt, so this patch cleans that up
removing the xtime_cache related code.

This is a bit simpler, but still could use some wider testing.

Signed-off-by: John Stultz 
Acked-by: Thomas Gleixner 
Reviewed-by: John Kacur 
Cc: Clark Williams 
Cc: Martin Schwidefsky 
Cc: Andrew Morton 
LKML-Reference: <1254525855.7741.95.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar