| Message ID | 20240511144436754EiKfJM4xjMSTyCbEExwcL@zte.com.cn (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [linux-next] mm/huge_memory: mark racy access on huge_anon_orders_always | expand |
On 11.05.24 08:44, xu.xin16@zte.com.cn wrote: > From: Ran Xiaokai <ran.xiaokai@zte.com.cn> > > huge_anon_orders_always and huge_anon_orders_always are accessed "huge_anon_orders_always" mentioned twice. > lockless, it is better to use the READ_ONCE() wrapper. > This is not fixing any visible bug, hopefully this can cease some > KCSAN complains in the future. > Also do that for huge_anon_orders_madvise. > > Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn> > --- > include/linux/huge_mm.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h > index de0c89105076..6573430ea600 100644 > --- a/include/linux/huge_mm.h > +++ b/include/linux/huge_mm.h > @@ -122,8 +122,8 @@ static inline bool hugepage_flags_enabled(void) > * So we don't need to look at huge_anon_orders_inherit. > */ > return hugepage_global_enabled() || > - huge_anon_orders_always || > - huge_anon_orders_madvise; > + READ_ONCE(huge_anon_orders_always) || > + READ_ONCE(huge_anon_orders_madvise); Don't mess up the alignment please. > } > > static inline int highest_order(unsigned long orders) Acked-by: David Hildenbrand <david@redhat.com>
On Sat, May 11, 2024 at 12:44 AM <xu.xin16@zte.com.cn> wrote: > > From: Ran Xiaokai <ran.xiaokai@zte.com.cn> > > huge_anon_orders_always and huge_anon_orders_always are accessed > lockless, it is better to use the READ_ONCE() wrapper. > This is not fixing any visible bug, hopefully this can cease some > KCSAN complains in the future. A little bit confused here. Did you see complaints from KCSAN? > Also do that for huge_anon_orders_madvise. > > Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn> > --- > include/linux/huge_mm.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h > index de0c89105076..6573430ea600 100644 > --- a/include/linux/huge_mm.h > +++ b/include/linux/huge_mm.h > @@ -122,8 +122,8 @@ static inline bool hugepage_flags_enabled(void) > * So we don't need to look at huge_anon_orders_inherit. > */ > return hugepage_global_enabled() || > - huge_anon_orders_always || > - huge_anon_orders_madvise; > + READ_ONCE(huge_anon_orders_always) || > + READ_ONCE(huge_anon_orders_madvise); > } > > static inline int highest_order(unsigned long orders) > -- > 2.15.2
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index de0c89105076..6573430ea600 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -122,8 +122,8 @@ static inline bool hugepage_flags_enabled(void) * So we don't need to look at huge_anon_orders_inherit. */ return hugepage_global_enabled() || - huge_anon_orders_always || - huge_anon_orders_madvise; + READ_ONCE(huge_anon_orders_always) || + READ_ONCE(huge_anon_orders_madvise); } static inline int highest_order(unsigned long orders)