Hi I think if the poision page is from patrol scrub, the page may be a just compound page in driver(not huge and transhuge), which it's ok for the following hwpoison_user_mappings. For PageTransHuge, we have split it, the the flags will be good. so I think the modification in the latest mmotm is OK -----Original Message----- From: Oscar Salvador [mailto:osalvador@xxxxxxx] Sent: Tuesday, September 8, 2020 3:26 PM To: HORIGUCHI NAOYA(堀口 直也) <naoya.horiguchi@xxxxxxx> Cc: yaoaili126@xxxxxxx; linux-mm@xxxxxxxxx; YANGFENG1 [杨峰] <YANGFENG1@xxxxxxxxxxxx>; yaoaili [么爱利] <yaoaili@xxxxxxxxxxxx>; willy@xxxxxxxxxxxxx Subject: Re: [PATCH] Fix incorrect compound page flags store On Tue, Sep 08, 2020 at 07:02:12AM +0000, HORIGUCHI NAOYA(堀口 直也) wrote: > On Mon, Sep 07, 2020 at 08:44:42PM -0700, yaoaili126@xxxxxxx wrote: > > From: Aili Yao <yaoaili@xxxxxxxxxxxx> > > > > PageHuge(p) branch will never be true,but for compound page we need to set page_flags to correct value. > > > > Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> > > Signed-off-by: Yang Feng < yangfeng1@xxxxxxxxxxxx> > > Signed-off-by: Aili Yao <yaoaili@xxxxxxxxxxxx> > > I found that this PageHuge() check is removed and no long exists in > the latest mmotm, so we don't have worry about it. I might be missing something, so bear with me. It is true that the PageHuge check is gone, but we are storing the page's flags in page_flags, even if the page is a tail (e.g: part of a compound page ). Should not we store heads' flags instead? AFAICS, hpage contains either the head of the compound page, or the page itself in case it is a normal page. -- Oscar Salvador SUSE L3
