Re: [PATCH 0/2] vtime: Remove pair of seqcount on context switch

[Frederic Weisbecker]

On Mon, Oct 07, 2019 at 06:20:31PM +0200, Ingo Molnar wrote:
> 
> * Frederic Weisbecker <frederic@xxxxxxxxxx> wrote:
> 
> > Extracted from a larger queue that fixes kcpustat on nohz_full, these
> > two patches have value on their own as they remove two write barriers
> > on nohz_full context switch.
> > 
> > Frederic Weisbecker (2):
> >   vtime: Rename vtime_account_system() to vtime_account_kernel()
> >   vtime: Spare a seqcount lock/unlock cycle on context switch
> > 
> >  arch/ia64/kernel/time.c          |  4 +--
> >  arch/powerpc/kernel/time.c       |  6 ++--
> >  arch/s390/kernel/vtime.c         |  4 +--
> >  include/linux/context_tracking.h |  4 +--
> >  include/linux/vtime.h            | 38 ++++++++++++------------
> >  kernel/sched/cputime.c           | 50 ++++++++++++++++++--------------
> >  6 files changed, 57 insertions(+), 49 deletions(-)
> 
> Which tree is this against? Doesn't apply cleanly to v5.4-rc2 nor v5.3. 
> Does it have any prereqs perhaps?

Indeed, you need to apply this fix first: https://lore.kernel.org/lkml/20190925214242.21873-1-frederic@xxxxxxxxxx/

"[PATCH] sched/vtime: Fix guest/system mis-accounting on task switch"

Thanks!