> -----Original Message----- > From: Konstantin Khlebnikov [mailto:koct9i@xxxxxxxxx] > Sent: Friday, December 05, 2014 2:39 PM > To: Kirill A. Shutemov > Cc: Wang, Yalin; linux-kernel@xxxxxxxxxxxxxxx; linux-mm@xxxxxxxxx; linux- > arm-kernel@xxxxxxxxxxxxxxxxxxx > Subject: Re: [RFC V2] mm:add zero_page _mapcount when mapped into user > space > > On Thu, Dec 4, 2014 at 3:28 PM, Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> > wrote: > > On Thu, Dec 04, 2014 at 02:10:53PM +0800, Wang, Yalin wrote: > >> > -----Original Message----- > >> > From: Kirill A. Shutemov [mailto:kirill@xxxxxxxxxxxxx] > >> > Sent: Tuesday, December 02, 2014 7:30 PM > >> > To: Wang, Yalin > >> > Cc: 'linux-kernel@xxxxxxxxxxxxxxx'; 'linux-mm@xxxxxxxxx'; > >> > 'linux-arm- kernel@xxxxxxxxxxxxxxxxxxx' > >> > Subject: Re: [RFC V2] mm:add zero_page _mapcount when mapped into > >> > user space > >> > > >> > On Tue, Dec 02, 2014 at 05:27:36PM +0800, Wang, Yalin wrote: > >> > > This patch add/dec zero_page's _mapcount to make sure the > >> > > mapcount is correct for zero_page, so that when read from > >> > > /proc/kpagecount, zero_page's mapcount is also correct, userspace > >> > > process like procrank can calculate PSS correctly. > > Instead of tweaking mapcount you could mark zero-pages in /proc/kpageflags > and handle them accordingly in userspace. Or mark zero pages with special > magic _mapcount and detect it in /proc/kpagecount. > I think add KPF_ZERO_PAGE in kpageflags is better. I will make another patch for review . Thanks ��.n������g��� �a��� �&ޖ)���)��h���&������梷���� �Ǟ�m������)������^�����������v���O��zf������