On Wed, 17 Aug 2022 16:13:47 -0300 Marcelo Tosatti <mtosatti@xxxxxxxxxx> wrote: > From: Aaron Tomlin <atomlin@xxxxxxxxxx> > > Add CPU-specific variable namely vmstat_dirty to indicate if > a vmstat imbalance is present for a given CPU. Therefore, at the > appropriate time, we can fold all the remaining differentials. > > This speeds up quiet_vmstat in case no per-CPU differentials exist. > > Based on > https://lore.kernel.org/lkml/20220204173554.763888172@fedora.localdomain/ > > Signed-off-by: Aaron Tomlin <atomlin@xxxxxxxxxx> > Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> > > --- > mm/vmstat.c | 54 ++++++++++++++++++++---------------------------------- > 1 file changed, 20 insertions(+), 34 deletions(-) > > Index: linux-2.6/mm/vmstat.c > =================================================================== > --- linux-2.6.orig/mm/vmstat.c > +++ linux-2.6/mm/vmstat.c > @@ -195,6 +195,12 @@ void fold_vm_numa_events(void) > #endif > > #ifdef CONFIG_SMP > +static DEFINE_PER_CPU_ALIGNED(bool, vmstat_dirty); > + > +static inline void mark_vmstat_dirty(void) > +{ > + this_cpu_write(vmstat_dirty, true); > +} If we're to have a helper for this then how about helpers for clearing it and reading it? Also, vmstat_mark_dirty(), vmstat_clear_dirty() and vmstat_dirty() would be better identifiers. Then those helper functions become good sites for comments explaining what's going on.
