From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx146.postini.com [74.125.245.146]) by kanga.kvack.org (Postfix) with SMTP id C12886B0062 for ; Mon, 12 Aug 2013 17:57:22 -0400 (EDT) Date: Mon, 12 Aug 2013 14:57:20 -0700 From: Andrew Morton Subject: Re: [patch 2/2] [PATCH] mm: Save soft-dirty bits on file pages Message-Id: <20130812145720.3b722b066fe1bd77291331e5@linux-foundation.org> In-Reply-To: <20130808145120.GA1775@moon> References: <20130730204154.407090410@gmail.com> <20130730204654.966378702@gmail.com> <20130807132812.60ad4bfe85127794094d385e@linux-foundation.org> <20130808145120.GA1775@moon> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Cyrill Gorcunov Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, luto@amacapital.net, xemul@parallels.com, mpm@selenic.com, xiaoguangrong@linux.vnet.ibm.com, mtosatti@redhat.com, kosaki.motohiro@gmail.com, sfr@canb.auug.org.au, peterz@infradead.org, aneesh.kumar@linux.vnet.ibm.com, Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner On Thu, 8 Aug 2013 18:51:20 +0400 Cyrill Gorcunov wrote: > On Wed, Aug 07, 2013 at 01:28:12PM -0700, Andrew Morton wrote: > > > > Good god. > > > > I wonder if these can be turned into out-of-line functions in some form > > which humans can understand. > > > > or > > > > #define pte_to_pgoff(pte) > > frob(pte, PTE_FILE_SHIFT1, PTE_FILE_BITS1) + > > frob(PTE_FILE_SHIFT2, PTE_FILE_BITS2) + > > frob(PTE_FILE_SHIFT3, PTE_FILE_BITS3) + > > frob(PTE_FILE_SHIFT4, PTE_FILE_BITS1 + PTE_FILE_BITS2 + PTE_FILE_BITS3) > > Hi, here is what I ended up with. Please take a look (I decided to post > patch in the thread since it's related to the context of the mails). You could have #undefed _mfrob and __frob after using them, but whatever. I saved this patch to wave at the x86 guys for 3.12. I plan to merge mm-save-soft-dirty-bits-on-file-pages.patch for 3.11. > Guys, is there a reason for "if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE" > test present in this pgtable-2level.h file at all? I can't imagine > where it can be false on x86. I doubt if "Guys" read this. x86 maintainers cc'ed. From: Cyrill Gorcunov Subject: arch/x86/include/asm/pgtable-2level.h: clean up pte_to_pgoff and pgoff_to_pte helpers Andrew asked if there a way to make pte_to_pgoff and pgoff_to_pte macro helpers somehow more readable. With this patch it should be more understandable what is happening with bits when they come to and from pte entry. Signed-off-by: Cyrill Gorcunov Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- arch/x86/include/asm/pgtable-2level.h | 82 ++++++++++++------------ 1 file changed, 41 insertions(+), 41 deletions(-) diff -puN arch/x86/include/asm/pgtable-2level.h~arch-x86-include-asm-pgtable-2levelh-clean-up-pte_to_pgoff-and-pgoff_to_pte-helpers arch/x86/include/asm/pgtable-2level.h --- a/arch/x86/include/asm/pgtable-2level.h~arch-x86-include-asm-pgtable-2levelh-clean-up-pte_to_pgoff-and-pgoff_to_pte-helpers +++ a/arch/x86/include/asm/pgtable-2level.h @@ -55,6 +55,9 @@ static inline pmd_t native_pmdp_get_and_ #define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp) #endif +#define _mfrob(v,r,m,l) ((((v) >> (r)) & (m)) << (l)) +#define __frob(v,r,l) (((v) >> (r)) << (l)) + #ifdef CONFIG_MEM_SOFT_DIRTY /* @@ -71,31 +74,27 @@ static inline pmd_t native_pmdp_get_and_ #define PTE_FILE_BITS2 (PTE_FILE_SHIFT3 - PTE_FILE_SHIFT2 - 1) #define PTE_FILE_BITS3 (PTE_FILE_SHIFT4 - PTE_FILE_SHIFT3 - 1) -#define pte_to_pgoff(pte) \ - ((((pte).pte_low >> (PTE_FILE_SHIFT1)) \ - & ((1U << PTE_FILE_BITS1) - 1))) \ - + ((((pte).pte_low >> (PTE_FILE_SHIFT2)) \ - & ((1U << PTE_FILE_BITS2) - 1)) \ - << (PTE_FILE_BITS1)) \ - + ((((pte).pte_low >> (PTE_FILE_SHIFT3)) \ - & ((1U << PTE_FILE_BITS3) - 1)) \ - << (PTE_FILE_BITS1 + PTE_FILE_BITS2)) \ - + ((((pte).pte_low >> (PTE_FILE_SHIFT4))) \ - << (PTE_FILE_BITS1 + PTE_FILE_BITS2 + PTE_FILE_BITS3)) - -#define pgoff_to_pte(off) \ - ((pte_t) { .pte_low = \ - ((((off)) & ((1U << PTE_FILE_BITS1) - 1)) << PTE_FILE_SHIFT1) \ - + ((((off) >> PTE_FILE_BITS1) \ - & ((1U << PTE_FILE_BITS2) - 1)) \ - << PTE_FILE_SHIFT2) \ - + ((((off) >> (PTE_FILE_BITS1 + PTE_FILE_BITS2)) \ - & ((1U << PTE_FILE_BITS3) - 1)) \ - << PTE_FILE_SHIFT3) \ - + ((((off) >> \ - (PTE_FILE_BITS1 + PTE_FILE_BITS2 + PTE_FILE_BITS3))) \ - << PTE_FILE_SHIFT4) \ - + _PAGE_FILE }) +#define PTE_FILE_MASK1 ((1U << PTE_FILE_BITS1) - 1) +#define PTE_FILE_MASK2 ((1U << PTE_FILE_BITS2) - 1) +#define PTE_FILE_MASK3 ((1U << PTE_FILE_BITS3) - 1) + +#define PTE_FILE_LSHIFT2 (PTE_FILE_BITS1) +#define PTE_FILE_LSHIFT3 (PTE_FILE_BITS1 + PTE_FILE_BITS2) +#define PTE_FILE_LSHIFT4 (PTE_FILE_BITS1 + PTE_FILE_BITS2 + PTE_FILE_BITS3) + +#define pte_to_pgoff(pte) \ + (_mfrob((pte).pte_low, PTE_FILE_SHIFT1, PTE_FILE_MASK1, 0) + \ + _mfrob((pte).pte_low, PTE_FILE_SHIFT2, PTE_FILE_MASK2, PTE_FILE_LSHIFT2) + \ + _mfrob((pte).pte_low, PTE_FILE_SHIFT3, PTE_FILE_MASK3, PTE_FILE_LSHIFT3) + \ + __frob((pte).pte_low, PTE_FILE_SHIFT4, PTE_FILE_LSHIFT4)) + +#define pgoff_to_pte(off) \ + ((pte_t) { .pte_low = \ + _mfrob(off, 0, PTE_FILE_MASK1, PTE_FILE_SHIFT1) + \ + _mfrob(off, PTE_FILE_LSHIFT2, PTE_FILE_MASK2, PTE_FILE_SHIFT2) + \ + _mfrob(off, PTE_FILE_LSHIFT3, PTE_FILE_MASK3, PTE_FILE_SHIFT3) + \ + __frob(off, PTE_FILE_LSHIFT4, PTE_FILE_SHIFT4) + \ + _PAGE_FILE }) #else /* CONFIG_MEM_SOFT_DIRTY */ @@ -115,22 +114,23 @@ static inline pmd_t native_pmdp_get_and_ #define PTE_FILE_BITS1 (PTE_FILE_SHIFT2 - PTE_FILE_SHIFT1 - 1) #define PTE_FILE_BITS2 (PTE_FILE_SHIFT3 - PTE_FILE_SHIFT2 - 1) -#define pte_to_pgoff(pte) \ - ((((pte).pte_low >> PTE_FILE_SHIFT1) \ - & ((1U << PTE_FILE_BITS1) - 1)) \ - + ((((pte).pte_low >> PTE_FILE_SHIFT2) \ - & ((1U << PTE_FILE_BITS2) - 1)) << PTE_FILE_BITS1) \ - + (((pte).pte_low >> PTE_FILE_SHIFT3) \ - << (PTE_FILE_BITS1 + PTE_FILE_BITS2))) - -#define pgoff_to_pte(off) \ - ((pte_t) { .pte_low = \ - (((off) & ((1U << PTE_FILE_BITS1) - 1)) << PTE_FILE_SHIFT1) \ - + ((((off) >> PTE_FILE_BITS1) & ((1U << PTE_FILE_BITS2) - 1)) \ - << PTE_FILE_SHIFT2) \ - + (((off) >> (PTE_FILE_BITS1 + PTE_FILE_BITS2)) \ - << PTE_FILE_SHIFT3) \ - + _PAGE_FILE }) +#define PTE_FILE_MASK1 ((1U << PTE_FILE_BITS1) - 1) +#define PTE_FILE_MASK2 ((1U << PTE_FILE_BITS2) - 1) + +#define PTE_FILE_LSHIFT2 (PTE_FILE_BITS1) +#define PTE_FILE_LSHIFT3 (PTE_FILE_BITS1 + PTE_FILE_BITS2) + +#define pte_to_pgoff(pte) \ + (_mfrob((pte).pte_low, PTE_FILE_SHIFT1, PTE_FILE_MASK1, 0) + \ + _mfrob((pte).pte_low, PTE_FILE_SHIFT2, PTE_FILE_MASK2, PTE_FILE_LSHIFT2) + \ + __frob((pte).pte_low, PTE_FILE_SHIFT3, PTE_FILE_LSHIFT3)) + +#define pgoff_to_pte(off) \ + ((pte_t) { .pte_low = \ + _mfrob(off, 0, PTE_FILE_MASK1, PTE_FILE_SHIFT1) + \ + _mfrob(off, PTE_FILE_LSHIFT2, PTE_FILE_MASK2, PTE_FILE_SHIFT2) + \ + __frob(off, PTE_FILE_LSHIFT3, PTE_FILE_SHIFT3) + \ + _PAGE_FILE }) #endif /* CONFIG_MEM_SOFT_DIRTY */ _ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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