From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELs4+L56OjxveuK7/5/OpA2D32Zfy1q3lJdgqdkpfcGeyeuH1HfhJxh7BmAtpK3MYagFIdHG ARC-Seal: i=1; a=rsa-sha256; t=1520376506; cv=none; d=google.com; s=arc-20160816; b=jZPABUCpO93vruNcSmh0mfL90wuqwekITfFxXYirgfLN97rA7Llj2yejXJDSdS50ar H8lqr5+RF1Bg5m06j847PVzSoZqi0SoVQgNN2XLVf9eZlUJICRTPIpK533nzB9ZUryu1 ewT8zqEGz4kS5s5WbMyaI2waWZ0x2Mi4Z7JDCcqVz7g2Acaifj3y6q9gv74GYMz/uQ/D PV20iYpU0VPq5LlQ8q0S/67ArLc3MDtrr7GgCVImMMazBRyRKfjswDSDj9DN9/B+pzIV ykxwydrwJIMxyefzwy6ihoofUt3OpFZGZUv7LXErF6Q3Z05FoC96VcDo2z467nnAxaHk jrPQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:arc-authentication-results; bh=rZ+MWbcusjcb4byTvpxy+8cp+dix0uRbm1S8PhOTVL8=; b=Kw1aMq1g9l39Kb6hw+69UaKcZzu/kDxO8qqewG75/pTxVR24MMgygkoV7mXqbqVoiS tk6TWyqeXUwCSzKJrXJ0I3Udkh9M5nw9vygsm6Lz6ADRwYrqoaxKZ8vAcIxPdA83ScPy VzHAqFiVsUL/IHQQ96qU2wazA/QeQ+03UOAqs1GJf52Cggdhqz6O6c3DFzJPVBtZX4mh 4uHUV6iaer/hoZY/GzHdaWujVzBz19+IXSU0yWm9uGFFU+b7H2hYTdharU6mq5j2bQcP P2Ny4fBlOl3Vo5JhWDF9I5C8rQG3E+YoCJ9jZ7WetBY2XzrNtHO9PB+0Dvkf0BeZaExT hH/A== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning akpm@linux-foundation.org does not designate 104.133.9.71 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning akpm@linux-foundation.org does not designate 104.133.9.71 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org Date: Tue, 6 Mar 2018 14:48:19 -0800 From: Andrew Morton To: Khalid Aziz Cc: davem@davemloft.net, dave.hansen@linux.intel.com, kstewart@linuxfoundation.org, pombredanne@nexb.com, tglx@linutronix.de, anthony.yznaga@oracle.com, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, sparclinux@vger.kernel.org, Khalid Aziz Subject: Re: [PATCH v12 09/11] mm: Allow arch code to override copy_highpage() Message-Id: <20180306144819.53e794acc83309fd8b401e92@linux-foundation.org> In-Reply-To: References: X-Mailer: Sylpheed 3.6.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1593031715838543761?= X-GMAIL-MSGID: =?utf-8?q?1594230315402308593?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed, 21 Feb 2018 10:15:51 -0700 Khalid Aziz wrote: > Some architectures can support metadata for memory pages and when a > page is copied, its metadata must also be copied. Sparc processors > from M7 onwards support metadata for memory pages. This metadata > provides tag based protection for access to memory pages. To maintain > this protection, the tag data must be copied to the new page when a > page is migrated across NUMA nodes. This patch allows arch specific > code to override default copy_highpage() and copy metadata along > with page data upon migration. > > ... > > --- a/include/linux/highmem.h > +++ b/include/linux/highmem.h > @@ -237,6 +237,8 @@ static inline void copy_user_highpage(struct page *to, struct page *from, > > #endif > > +#ifndef __HAVE_ARCH_COPY_HIGHPAGE > + > static inline void copy_highpage(struct page *to, struct page *from) > { > char *vfrom, *vto; > @@ -248,4 +250,6 @@ static inline void copy_highpage(struct page *to, struct page *from) > kunmap_atomic(vfrom); > } > > +#endif > + > #endif /* _LINUX_HIGHMEM_H */ It would be more consistent and conventional here to do #ifndef copy_highpage static inline void copy_highpage(struct page *to, struct page *from) { ... } #define copy_highpage copy_highpage As is happening in [patch 07/11]. And a similar change could be made to [patch 02/11], actually. Either way, Acked-by: Andrew Morton