1. 20 5月, 2016 1 次提交
  2. 23 4月, 2016 1 次提交
    • B
      time: Introduce do_sys_settimeofday64() · 86d34732
      Baolin Wang 提交于
      The do_sys_settimeofday() function uses a timespec, which is not year
      2038 safe on 32bit systems.
      
      Thus this patch introduces do_sys_settimeofday64(), which allows us to
      transition users of do_sys_settimeofday() to using 64bit time types.
      
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@kernel.org>
      Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
      [jstultz: Include errno-base.h to avoid build issue on some arches]
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      86d34732
  3. 29 2月, 2016 1 次提交
    • D
      Handle ISO 8601 leap seconds and encodings of midnight in mktime64() · ede5147d
      David Howells 提交于
      Handle the following ISO 8601 features in mktime64():
      
       (1) Leap seconds.
      
           Leap seconds are indicated by the seconds parameter being the value
           60.  Handle this by treating it the same as 00 of the following
           minute.
      
           It has been pointed out that a minute may contain two leap seconds.
           However, pending discussion of what that looks like and how to handle
           it, I'm not going to concern myself with it.
      
       (2) Alternate encodings of midnight.
      
           Two different encodings of midnight are permitted - 00:00:00 and
           24:00:00 - the first is midnight today and the second is midnight
           tomorrow and is exactly equivalent to the first with tomorrow's date.
      
      As it happens, we don't actually need to change mktime64() to handle either
      of these - just comment them as valid parameters.
      
      These facility will be used by the X.509 parser.  Doing it in mktime64()
      makes the policy common to the whole kernel and easier to find.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Acked-by: NArnd Bergmann <arnd@arndb.de>
      cc: John Stultz <john.stultz@linaro.org>
      cc: Rudolf Polzer <rpolzer@google.com>
      cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
      ede5147d
  4. 18 8月, 2015 2 次提交
    • B
      time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64() · 9ca30850
      Baolin Wang 提交于
      The conversion between struct timespec and jiffies is not year 2038
      safe on 32bit systems. Introduce timespec64_to_jiffies() and
      jiffies_to_timespec64() functions which use struct timespec64 to
      make it ready for 2038 issue.
      
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      9ca30850
    • K
      time: Fix nanosecond file time rounding in timespec_trunc() · de4a95fa
      Karsten Blees 提交于
      timespec_trunc() avoids rounding if granularity <= nanoseconds-per-jiffie
      (or TICK_NSEC). This optimization assumes that:
      
       1. current_kernel_time().tv_nsec is already rounded to TICK_NSEC (i.e.
          with HZ=1000 you'd get 1000000, 2000000, 3000000... but never 1000001).
          This is no longer true (probably since hrtimers introduced in 2.6.16).
      
       2. TICK_NSEC is evenly divisible by all possible granularities. This may
          be true for HZ=100, 250, 1000, but obviously not for HZ=300 /
          TICK_NSEC=3333333 (introduced in 2.6.20).
      
      Thus, sub-second portions of in-core file times are not rounded to on-disk
      granularity. I.e. file times may change when the inode is re-read from disk
      or when the file system is remounted.
      
      This affects all file systems with file time granularities > 1 ns and < 1s,
      e.g. CEPH (1000 ns), UDF (1000 ns), CIFS (100 ns), NTFS (100 ns) and FUSE
      (configurable from user mode via struct fuse_init_out.time_gran).
      
      Steps to reproduce with e.g. UDF:
      
        $ dd if=/dev/zero of=udfdisk count=10000 && mkudffs udfdisk
        $ mkdir udf && mount udfdisk udf
        $ touch udf/test && stat -c %y udf/test
        2015-06-09 10:22:56.130006767 +0200
        $ umount udf && mount udfdisk udf
        $ stat -c %y udf/test
        2015-06-09 10:22:56.130006000 +0200
      
      Remounting truncates the mtime to 1 µs.
      
      Fix the rounding in timespec_trunc() and update the documentation.
      
      timespec_trunc() is exclusively used to calculate inode's [acm]time (mostly
      via current_fs_time()), and always with super_block.s_time_gran as second
      argument. So this can safely be changed without side effects.
      
      Note: This does _not_ fix the issue for FAT's 2 second mtime resolution,
      as super_block.s_time_gran isn't prepared to handle different ctime /
      mtime / atime resolutions nor resolutions > 1 second.
      
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NKarsten Blees <blees@dcon.de>
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      de4a95fa
  5. 29 7月, 2015 1 次提交
    • F
      jiffies: Remove HZ > USEC_PER_SEC special case · e0758676
      Frederic Weisbecker 提交于
      HZ never goes much further 1000 and a bit. And if we ever reach one tick
      per microsecond, we might be having a problem.
      
      Lets stop maintaining this special case, just leave a paranoid check.
      Reviewed-by: NRik van Riel <riel@redhat.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc; John Stultz <john.stultz@linaro.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Viresh Kumar <viresh.kumar@linaro.org>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      e0758676
  6. 10 6月, 2015 1 次提交
  7. 23 5月, 2015 1 次提交
  8. 19 5月, 2015 2 次提交
  9. 08 1月, 2015 1 次提交
  10. 05 12月, 2014 1 次提交
  11. 22 11月, 2014 1 次提交
  12. 13 9月, 2014 1 次提交
    • A
      jiffies: Fix timeval conversion to jiffies · d78c9300
      Andrew Hunter 提交于
      timeval_to_jiffies tried to round a timeval up to an integral number
      of jiffies, but the logic for doing so was incorrect: intervals
      corresponding to exactly N jiffies would become N+1. This manifested
      itself particularly repeatedly stopping/starting an itimer:
      
      setitimer(ITIMER_PROF, &val, NULL);
      setitimer(ITIMER_PROF, NULL, &val);
      
      would add a full tick to val, _even if it was exactly representable in
      terms of jiffies_ (say, the result of a previous rounding.)  Doing
      this repeatedly would cause unbounded growth in val.  So fix the math.
      
      Here's what was wrong with the conversion: we essentially computed
      (eliding seconds)
      
      jiffies = usec  * (NSEC_PER_USEC/TICK_NSEC)
      
      by using scaling arithmetic, which took the best approximation of
      NSEC_PER_USEC/TICK_NSEC with denominator of 2^USEC_JIFFIE_SC =
      x/(2^USEC_JIFFIE_SC), and computed:
      
      jiffies = (usec * x) >> USEC_JIFFIE_SC
      
      and rounded this calculation up in the intermediate form (since we
      can't necessarily exactly represent TICK_NSEC in usec.) But the
      scaling arithmetic is a (very slight) *over*approximation of the true
      value; that is, instead of dividing by (1 usec/ 1 jiffie), we
      effectively divided by (1 usec/1 jiffie)-epsilon (rounding
      down). This would normally be fine, but we want to round timeouts up,
      and we did so by adding 2^USEC_JIFFIE_SC - 1 before the shift; this
      would be fine if our division was exact, but dividing this by the
      slightly smaller factor was equivalent to adding just _over_ 1 to the
      final result (instead of just _under_ 1, as desired.)
      
      In particular, with HZ=1000, we consistently computed that 10000 usec
      was 11 jiffies; the same was true for any exact multiple of
      TICK_NSEC.
      
      We could possibly still round in the intermediate form, adding
      something less than 2^USEC_JIFFIE_SC - 1, but easier still is to
      convert usec->nsec, round in nanoseconds, and then convert using
      time*spec*_to_jiffies.  This adds one constant multiplication, and is
      not observably slower in microbenchmarks on recent x86 hardware.
      
      Tested: the following program:
      
      int main() {
        struct itimerval zero = {{0, 0}, {0, 0}};
        /* Initially set to 10 ms. */
        struct itimerval initial = zero;
        initial.it_interval.tv_usec = 10000;
        setitimer(ITIMER_PROF, &initial, NULL);
        /* Save and restore several times. */
        for (size_t i = 0; i < 10; ++i) {
          struct itimerval prev;
          setitimer(ITIMER_PROF, &zero, &prev);
          /* on old kernels, this goes up by TICK_USEC every iteration */
          printf("previous value: %ld %ld %ld %ld\n",
                 prev.it_interval.tv_sec, prev.it_interval.tv_usec,
                 prev.it_value.tv_sec, prev.it_value.tv_usec);
          setitimer(ITIMER_PROF, &prev, NULL);
        }
          return 0;
      }
      
      Cc: stable@vger.kernel.org
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Paul Turner <pjt@google.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Reviewed-by: NPaul Turner <pjt@google.com>
      Reported-by: NAaron Jacobs <jacobsa@google.com>
      Signed-off-by: NAndrew Hunter <ahh@google.com>
      [jstultz: Tweaked to apply to 3.17-rc]
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      d78c9300
  13. 24 7月, 2014 3 次提交
  14. 23 6月, 2014 1 次提交
  15. 19 6月, 2013 1 次提交
  16. 16 3月, 2013 2 次提交
  17. 22 2月, 2013 1 次提交
  18. 09 2月, 2013 1 次提交
    • P
      time, Fix setting of hardware clock in NTP code · 84e345e4
      Prarit Bhargava 提交于
      At init time, if the system time is "warped" forward in warp_clock()
      it will differ from the hardware clock by sys_tz.tz_minuteswest.  This time
      difference is not taken into account when ntp updates the hardware clock,
      and this causes the system time to jump forward by this offset every reboot.
      
      The kernel must take this offset into account when writing the system time
      to the hardware clock in the ntp code.  This patch adds
      persistent_clock_is_local which indicates that an offset has been applied
      in warp_clock() and accounts for the "warp" before writing the hardware
      clock.
      
      x86 does not have this problem as rtc writes are software limited to a
      +/-15 minute window relative to the current rtc time.  Other arches, such
      as powerpc, however do a full synchronization of the system time to the
      rtc and will see this problem.
      
      [v2]: generated against tip/timers/core
      Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
      Cc: John Stultz <john.stultz@linaro.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      84e345e4
  19. 25 9月, 2012 1 次提交
    • J
      time: Move update_vsyscall definitions to timekeeper_internal.h · 189374ae
      John Stultz 提交于
      Since users will need to include timekeeper_internal.h, move
      update_vsyscall definitions to timekeeper_internal.h.
      
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Paul Turner <pjt@google.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      189374ae
  20. 16 3月, 2012 1 次提交
  21. 31 10月, 2011 1 次提交
  22. 21 9月, 2011 1 次提交
  23. 02 2月, 2011 1 次提交
  24. 31 1月, 2011 1 次提交
  25. 26 1月, 2011 1 次提交
  26. 29 11月, 2010 1 次提交
    • J
      Kill off a bunch of warning: ‘inline’ is not at beginning of declaration · fa9f90be
      Jesper Juhl 提交于
      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: NJesper Juhl <jj@chaosbits.net>
      Signed-off-by: NJiri Kosina <jkosina@suse.cz>
      fa9f90be
  27. 27 7月, 2010 1 次提交
  28. 24 5月, 2010 1 次提交
  29. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      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: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  30. 13 3月, 2010 1 次提交
  31. 23 12月, 2009 1 次提交
    • L
      Revert "time: Remove xtime_cache" · 83f57a11
      Linus Torvalds 提交于
      This reverts commit 7bc7d637, 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: NPetr Titěra <P.Titera@century.cz>
      Requested-by: Njohn stultz <johnstul@us.ibm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      83f57a11
  32. 26 11月, 2009 1 次提交
    • H
      sched, time: Define nsecs_to_jiffies() · b7b20df9
      Hidetoshi Seto 提交于
      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: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
      Acked-by: NPeter Zijlstra <peterz@infradead.org>
      Cc: Stanislaw Gruszka <sgruszka@redhat.com>
      Cc: Spencer Candland <spencer@bluehost.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Balbir Singh <balbir@in.ibm.com>
      Cc: Amrico Wang <xiyou.wangcong@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: John Stultz <johnstul@linux.vnet.ibm.com>
      LKML-Reference: <4B0E16E7.5070307@jp.fujitsu.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      b7b20df9
  33. 05 10月, 2009 1 次提交
    • J
      time: Remove xtime_cache · 7bc7d637
      john stultz 提交于
      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: NJohn Stultz <johnstul@us.ibm.com>
      Acked-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NJohn Kacur <jkacur@redhat.com>
      Cc: Clark Williams <williams@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      LKML-Reference: <1254525855.7741.95.camel@localhost.localdomain>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      7bc7d637
  34. 15 9月, 2009 1 次提交
    • T
      time: Prevent 32 bit overflow with set_normalized_timespec() · 12e09337
      Thomas Gleixner 提交于
      set_normalized_timespec() nsec argument is of type long. The recent
      timekeeping changes of ktime_get_ts() feed 
      
      	ts->tv_nsec + tomono.tv_nsec + nsecs
      
      to set_normalized_timespec(). On 32 bit machines that sum can be
      larger than (1 << 31) and therefor result in a negative value which
      screws up the result completely.
      
      Make the nsec argument of set_normalized_timespec() s64 to fix the
      problem at hand. This also prevents similar problems for future users
      of set_normalized_timespec().
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NCarsten Emde <carsten.emde@osadl.org>
      LKML-Reference: <new-submission>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: John Stultz <johnstul@us.ibm.com>
      12e09337
  35. 14 1月, 2009 1 次提交