* [patch 0/2] A few simplifications for softdirty memory tracker code @ 2014-04-25 8:10 Cyrill Gorcunov 2014-04-25 8:10 ` [patch 1/2] mm: pgtable -- Drop unneeded preprocessor ifdef Cyrill Gorcunov 2014-04-25 8:10 ` [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker Cyrill Gorcunov 0 siblings, 2 replies; 7+ messages in thread From: Cyrill Gorcunov @ 2014-04-25 8:10 UTC (permalink / raw) To: linux-kernel Cc: linux-mm, torvalds, mgorman, hpa, mingo, steven, riel, david.vrabel, akpm, peterz, xemul, gorcunov Hi, here are a few simplifications for softdirty memory tracker code, in particular we dropped off x86-32 support since it seems noone needed it here on x86 platform. As Andrew requested I've rebased patches on top of current linux-next repo. Also at first I wanted to rip off _PAGE_PSE bit which we use in swap ptes to track dirty status of swapped pages and reuse _PAGE_BIT_SOFT_DIRTY instead. It's still possible but requires additional shrinking of maximal swap size and I don't know if it's acceptible or not. Currently we have #ifdef CONFIG_NUMA_BALANCING /* Automatic NUMA balancing needs to be distinguishable from swap entries */ #define SWP_OFFSET_SHIFT (_PAGE_BIT_PROTNONE + 2) #else #define SWP_OFFSET_SHIFT (_PAGE_BIT_PROTNONE + 1) #endif If I reuse _PAGE_BIT_SOFT_DIRTY I'll have to increase this shift up to bit 11, which, again, I think is too much, right? Comments are highly appreciated! Cyrill -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 7+ messages in thread
* [patch 1/2] mm: pgtable -- Drop unneeded preprocessor ifdef 2014-04-25 8:10 [patch 0/2] A few simplifications for softdirty memory tracker code Cyrill Gorcunov @ 2014-04-25 8:10 ` Cyrill Gorcunov 2014-04-25 8:10 ` [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker Cyrill Gorcunov 1 sibling, 0 replies; 7+ messages in thread From: Cyrill Gorcunov @ 2014-04-25 8:10 UTC (permalink / raw) To: linux-kernel Cc: linux-mm, torvalds, mgorman, hpa, mingo, steven, riel, david.vrabel, akpm, peterz, xemul, gorcunov [-- Attachment #1: pgbits-drop-if --] [-- Type: text/plain, Size: 3246 bytes --] _PAGE_BIT_FILE (bit 6) is always less than _PAGE_BIT_PROTNONE (bit 8), so drop redundant #ifdef. CC: Linus Torvalds <torvalds@linux-foundation.org> CC: Mel Gorman <mgorman@suse.de> CC: Peter Anvin <hpa@zytor.com> CC: Ingo Molnar <mingo@kernel.org> CC: Steven Noonan <steven@uplinklabs.net> CC: Rik van Riel <riel@redhat.com> CC: David Vrabel <david.vrabel@citrix.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Peter Zijlstra <peterz@infradead.org> CC: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> --- arch/x86/include/asm/pgtable-2level.h | 10 ---------- arch/x86/include/asm/pgtable_64.h | 8 -------- 2 files changed, 18 deletions(-) Index: linux-2.6.git/arch/x86/include/asm/pgtable-2level.h =================================================================== --- linux-2.6.git.orig/arch/x86/include/asm/pgtable-2level.h +++ linux-2.6.git/arch/x86/include/asm/pgtable-2level.h @@ -115,13 +115,8 @@ static __always_inline pte_t pgoff_to_pt */ #define PTE_FILE_MAX_BITS 29 #define PTE_FILE_SHIFT1 (_PAGE_BIT_PRESENT + 1) -#if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE #define PTE_FILE_SHIFT2 (_PAGE_BIT_FILE + 1) #define PTE_FILE_SHIFT3 (_PAGE_BIT_PROTNONE + 1) -#else -#define PTE_FILE_SHIFT2 (_PAGE_BIT_PROTNONE + 1) -#define PTE_FILE_SHIFT3 (_PAGE_BIT_FILE + 1) -#endif #define PTE_FILE_BITS1 (PTE_FILE_SHIFT2 - PTE_FILE_SHIFT1 - 1) #define PTE_FILE_BITS2 (PTE_FILE_SHIFT3 - PTE_FILE_SHIFT2 - 1) @@ -153,13 +148,8 @@ static __always_inline pte_t pgoff_to_pt #endif /* CONFIG_MEM_SOFT_DIRTY */ /* Encode and de-code a swap entry */ -#if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE #define SWP_TYPE_BITS (_PAGE_BIT_FILE - _PAGE_BIT_PRESENT - 1) #define SWP_OFFSET_SHIFT (_PAGE_BIT_PROTNONE + 1) -#else -#define SWP_TYPE_BITS (_PAGE_BIT_PROTNONE - _PAGE_BIT_PRESENT - 1) -#define SWP_OFFSET_SHIFT (_PAGE_BIT_FILE + 1) -#endif #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS) Index: linux-2.6.git/arch/x86/include/asm/pgtable_64.h =================================================================== --- linux-2.6.git.orig/arch/x86/include/asm/pgtable_64.h +++ linux-2.6.git/arch/x86/include/asm/pgtable_64.h @@ -143,7 +143,6 @@ static inline int pgd_large(pgd_t pgd) { #define pte_unmap(pte) ((void)(pte))/* NOP */ /* Encode and de-code a swap entry */ -#if _PAGE_BIT_FILE < _PAGE_BIT_PROTNONE #define SWP_TYPE_BITS (_PAGE_BIT_FILE - _PAGE_BIT_PRESENT - 1) #ifdef CONFIG_NUMA_BALANCING /* Automatic NUMA balancing needs to be distinguishable from swap entries */ @@ -151,13 +150,6 @@ static inline int pgd_large(pgd_t pgd) { #else #define SWP_OFFSET_SHIFT (_PAGE_BIT_PROTNONE + 1) #endif -#else -#ifdef CONFIG_NUMA_BALANCING -#error Incompatible format for automatic NUMA balancing -#endif -#define SWP_TYPE_BITS (_PAGE_BIT_PROTNONE - _PAGE_BIT_PRESENT - 1) -#define SWP_OFFSET_SHIFT (_PAGE_BIT_FILE + 1) -#endif #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 7+ messages in thread
* [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker 2014-04-25 8:10 [patch 0/2] A few simplifications for softdirty memory tracker code Cyrill Gorcunov 2014-04-25 8:10 ` [patch 1/2] mm: pgtable -- Drop unneeded preprocessor ifdef Cyrill Gorcunov @ 2014-04-25 8:10 ` Cyrill Gorcunov 2014-05-05 23:31 ` Andrew Morton 2014-05-06 16:28 ` [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker H. Peter Anvin 1 sibling, 2 replies; 7+ messages in thread From: Cyrill Gorcunov @ 2014-04-25 8:10 UTC (permalink / raw) To: linux-kernel Cc: linux-mm, torvalds, mgorman, hpa, mingo, steven, riel, david.vrabel, akpm, peterz, xemul, gorcunov [-- Attachment #1: pgbits-drop-softdirty-non-x86-64 --] [-- Type: text/plain, Size: 4569 bytes --] Tracking dirty status on 2 level pages requires very ugly macros and taking into account how old the machines who can operate without PAE mode only are, lets drop soft dirty tracker from them for code simplicity (note I can't drop all the macros from 2 level pages by now since _PAGE_BIT_PROTNONE and _PAGE_BIT_FILE are still used even without tracker). Linus proposed to completely rip off softdirty support on x86-32 (even with PAE) and since for CRIU we're not planning to support native x86-32 mode, lets do that. (Softdirty tracker is relatively new feature which mostly used by CRIU so I don't expect if such API change would cause problems on userspace). CC: Linus Torvalds <torvalds@linux-foundation.org> CC: Mel Gorman <mgorman@suse.de> CC: Peter Anvin <hpa@zytor.com> CC: Ingo Molnar <mingo@kernel.org> CC: Steven Noonan <steven@uplinklabs.net> CC: Rik van Riel <riel@redhat.com> CC: David Vrabel <david.vrabel@citrix.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Peter Zijlstra <peterz@infradead.org> CC: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> --- arch/x86/Kconfig | 2 - arch/x86/include/asm/pgtable-2level.h | 49 ---------------------------------- 2 files changed, 1 insertion(+), 50 deletions(-) Index: linux-2.6.git/arch/x86/Kconfig =================================================================== --- linux-2.6.git.orig/arch/x86/Kconfig +++ linux-2.6.git/arch/x86/Kconfig @@ -106,7 +106,7 @@ config X86 select HAVE_ARCH_SECCOMP_FILTER select BUILDTIME_EXTABLE_SORT select GENERIC_CMOS_UPDATE - select HAVE_ARCH_SOFT_DIRTY + select HAVE_ARCH_SOFT_DIRTY if X86_64 select CLOCKSOURCE_WATCHDOG select GENERIC_CLOCKEVENTS select ARCH_CLOCKSOURCE_DATA Index: linux-2.6.git/arch/x86/include/asm/pgtable-2level.h =================================================================== --- linux-2.6.git.orig/arch/x86/include/asm/pgtable-2level.h +++ linux-2.6.git/arch/x86/include/asm/pgtable-2level.h @@ -62,53 +62,6 @@ static inline unsigned long pte_bitop(un return ((value >> rightshift) & mask) << leftshift; } -#ifdef CONFIG_MEM_SOFT_DIRTY - -/* - * Bits _PAGE_BIT_PRESENT, _PAGE_BIT_FILE, _PAGE_BIT_SOFT_DIRTY and - * _PAGE_BIT_PROTNONE are taken, split up the 28 bits of offset - * into this range. - */ -#define PTE_FILE_MAX_BITS 28 -#define PTE_FILE_SHIFT1 (_PAGE_BIT_PRESENT + 1) -#define PTE_FILE_SHIFT2 (_PAGE_BIT_FILE + 1) -#define PTE_FILE_SHIFT3 (_PAGE_BIT_PROTNONE + 1) -#define PTE_FILE_SHIFT4 (_PAGE_BIT_SOFT_DIRTY + 1) -#define PTE_FILE_BITS1 (PTE_FILE_SHIFT2 - PTE_FILE_SHIFT1 - 1) -#define PTE_FILE_BITS2 (PTE_FILE_SHIFT3 - PTE_FILE_SHIFT2 - 1) -#define PTE_FILE_BITS3 (PTE_FILE_SHIFT4 - PTE_FILE_SHIFT3 - 1) - -#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) - -static __always_inline pgoff_t pte_to_pgoff(pte_t pte) -{ - return (pgoff_t) - (pte_bitop(pte.pte_low, PTE_FILE_SHIFT1, PTE_FILE_MASK1, 0) + - pte_bitop(pte.pte_low, PTE_FILE_SHIFT2, PTE_FILE_MASK2, PTE_FILE_LSHIFT2) + - pte_bitop(pte.pte_low, PTE_FILE_SHIFT3, PTE_FILE_MASK3, PTE_FILE_LSHIFT3) + - pte_bitop(pte.pte_low, PTE_FILE_SHIFT4, -1UL, PTE_FILE_LSHIFT4)); -} - -static __always_inline pte_t pgoff_to_pte(pgoff_t off) -{ - return (pte_t){ - .pte_low = - pte_bitop(off, 0, PTE_FILE_MASK1, PTE_FILE_SHIFT1) + - pte_bitop(off, PTE_FILE_LSHIFT2, PTE_FILE_MASK2, PTE_FILE_SHIFT2) + - pte_bitop(off, PTE_FILE_LSHIFT3, PTE_FILE_MASK3, PTE_FILE_SHIFT3) + - pte_bitop(off, PTE_FILE_LSHIFT4, -1UL, PTE_FILE_SHIFT4) + - _PAGE_FILE, - }; -} - -#else /* CONFIG_MEM_SOFT_DIRTY */ - /* * Bits _PAGE_BIT_PRESENT, _PAGE_BIT_FILE and _PAGE_BIT_PROTNONE are taken, * split up the 29 bits of offset into this range. @@ -145,8 +98,6 @@ static __always_inline pte_t pgoff_to_pt }; } -#endif /* CONFIG_MEM_SOFT_DIRTY */ - /* Encode and de-code a swap entry */ #define SWP_TYPE_BITS (_PAGE_BIT_FILE - _PAGE_BIT_PRESENT - 1) #define SWP_OFFSET_SHIFT (_PAGE_BIT_PROTNONE + 1) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker 2014-04-25 8:10 ` [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker Cyrill Gorcunov @ 2014-05-05 23:31 ` Andrew Morton 2014-05-06 8:25 ` [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker, v2 Cyrill Gorcunov 2014-05-06 16:28 ` [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker H. Peter Anvin 1 sibling, 1 reply; 7+ messages in thread From: Andrew Morton @ 2014-05-05 23:31 UTC (permalink / raw) To: Cyrill Gorcunov Cc: linux-kernel, linux-mm, torvalds, mgorman, hpa, mingo, steven, riel, david.vrabel, peterz, xemul On Fri, 25 Apr 2014 12:10:32 +0400 Cyrill Gorcunov <gorcunov@openvz.org> wrote: > Tracking dirty status on 2 level pages requires very ugly macros > and taking into account how old the machines who can operate > without PAE mode only are, lets drop soft dirty tracker from > them for code simplicity (note I can't drop all the macros > from 2 level pages by now since _PAGE_BIT_PROTNONE and > _PAGE_BIT_FILE are still used even without tracker). > > Linus proposed to completely rip off softdirty support on > x86-32 (even with PAE) and since for CRIU we're not planning > to support native x86-32 mode, lets do that. > > (Softdirty tracker is relatively new feature which mostly used > by CRIU so I don't expect if such API change would cause problems > on userspace). i386 allnoconfig: In file included from /usr/src/25/arch/x86/include/asm/pgtable.h:886, from include/linux/mm.h:51, from include/linux/suspend.h:8, from arch/x86/kernel/asm-offsets.c:12: include/asm-generic/pgtable.h:414: error: redefinition of 'pte_soft_dirty' /usr/src/25/arch/x86/include/asm/pgtable.h:300: note: previous definition of 'pte_soft_dirty' was here include/asm-generic/pgtable.h:419: error: redefinition of 'pmd_soft_dirty' /usr/src/25/arch/x86/include/asm/pgtable.h:305: note: previous definition of 'pmd_soft_dirty' was here include/asm-generic/pgtable.h:424: error: redefinition of 'pte_mksoft_dirty' /usr/src/25/arch/x86/include/asm/pgtable.h:310: note: previous definition of 'pte_mksoft_dirty' was here include/asm-generic/pgtable.h:429: error: redefinition of 'pmd_mksoft_dirty' /usr/src/25/arch/x86/include/asm/pgtable.h:315: note: previous definition of 'pmd_mksoft_dirty' was here include/asm-generic/pgtable.h:434: error: redefinition of 'pte_swp_mksoft_dirty' /usr/src/25/arch/x86/include/asm/pgtable.h:868: note: previous definition of 'pte_swp_mksoft_dirty' was here include/asm-generic/pgtable.h:439: error: redefinition of 'pte_swp_soft_dirty' /usr/src/25/arch/x86/include/asm/pgtable.h:874: note: previous definition of 'pte_swp_soft_dirty' was here include/asm-generic/pgtable.h:444: error: redefinition of 'pte_swp_clear_soft_dirty' /usr/src/25/arch/x86/include/asm/pgtable.h:880: note: previous definition of 'pte_swp_clear_soft_dirty' was here include/asm-generic/pgtable.h:449: error: redefinition of 'pte_file_clear_soft_dirty' /usr/src/25/arch/x86/include/asm/pgtable.h:320: note: previous definition of 'pte_file_clear_soft_dirty' was here include/asm-generic/pgtable.h:454: error: redefinition of 'pte_file_mksoft_dirty' /usr/src/25/arch/x86/include/asm/pgtable.h:325: note: previous definition of 'pte_file_mksoft_dirty' was here include/asm-generic/pgtable.h:459: error: redefinition of 'pte_file_soft_dirty' /usr/src/25/arch/x86/include/asm/pgtable.h:330: note: previous definition of 'pte_file_soft_dirty' was here -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 7+ messages in thread
* [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker, v2 2014-05-05 23:31 ` Andrew Morton @ 2014-05-06 8:25 ` Cyrill Gorcunov 0 siblings, 0 replies; 7+ messages in thread From: Cyrill Gorcunov @ 2014-05-06 8:25 UTC (permalink / raw) To: Andrew Morton Cc: linux-kernel, linux-mm, torvalds, mgorman, hpa, mingo, steven, riel, david.vrabel, peterz, xemul On Mon, May 05, 2014 at 04:31:23PM -0700, Andrew Morton wrote: > On Fri, 25 Apr 2014 12:10:32 +0400 Cyrill Gorcunov <gorcunov@openvz.org> wrote: > > > Tracking dirty status on 2 level pages requires very ugly macros > > and taking into account how old the machines who can operate > > without PAE mode only are, lets drop soft dirty tracker from > > them for code simplicity (note I can't drop all the macros > > from 2 level pages by now since _PAGE_BIT_PROTNONE and > > _PAGE_BIT_FILE are still used even without tracker). > > > > Linus proposed to completely rip off softdirty support on > > x86-32 (even with PAE) and since for CRIU we're not planning > > to support native x86-32 mode, lets do that. > > > > (Softdirty tracker is relatively new feature which mostly used > > by CRIU so I don't expect if such API change would cause problems > > on userspace). > > i386 allnoconfig: > > In file included from /usr/src/25/arch/x86/include/asm/pgtable.h:886, Thanks! Here is an updated version. --- From: Cyrill Gorcunov <gorcunov@openvz.org> Subject: [PATCH -next] mm: pgtable -- Require X86_64 for soft-dirty tracker Tracking dirty status on 2 level pages requires very ugly macros and taking into account how old the machines who can operate without PAE mode only are, lets drop soft dirty tracker from them for code simplicity (note I can't drop all the macros from 2 level pages by now since _PAGE_BIT_PROTNONE and _PAGE_BIT_FILE are still used even without tracker). Linus proposed to completely rip off softdirty support on x86-32 (even with PAE) and since for CRIU we're not planning to support native x86-32 mode, lets do that. (Softdirty tracker is relatively new feature which mostly used by CRIU so I don't expect if such API change would cause problems on userspace). v2 (by akpm@): - guard helpers with CONFIG_HAVE_ARCH_SOFT_DIRTY on i386, otherwise it fails to build because we've a generic definitions in asm-generic/pgtable.h CC: Linus Torvalds <torvalds@linux-foundation.org> CC: Mel Gorman <mgorman@suse.de> CC: Peter Anvin <hpa@zytor.com> CC: Ingo Molnar <mingo@kernel.org> CC: Steven Noonan <steven@uplinklabs.net> CC: Rik van Riel <riel@redhat.com> CC: David Vrabel <david.vrabel@citrix.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Peter Zijlstra <peterz@infradead.org> CC: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> --- arch/x86/Kconfig | 2 - arch/x86/include/asm/pgtable-2level.h | 49 ---------------------------------- arch/x86/include/asm/pgtable.h | 5 +++ 3 files changed, 6 insertions(+), 50 deletions(-) Index: linux-2.6.git/arch/x86/Kconfig =================================================================== --- linux-2.6.git.orig/arch/x86/Kconfig +++ linux-2.6.git/arch/x86/Kconfig @@ -106,7 +106,7 @@ config X86 select HAVE_ARCH_SECCOMP_FILTER select BUILDTIME_EXTABLE_SORT select GENERIC_CMOS_UPDATE - select HAVE_ARCH_SOFT_DIRTY + select HAVE_ARCH_SOFT_DIRTY if X86_64 select CLOCKSOURCE_WATCHDOG select GENERIC_CLOCKEVENTS select ARCH_CLOCKSOURCE_DATA Index: linux-2.6.git/arch/x86/include/asm/pgtable-2level.h =================================================================== --- linux-2.6.git.orig/arch/x86/include/asm/pgtable-2level.h +++ linux-2.6.git/arch/x86/include/asm/pgtable-2level.h @@ -62,53 +62,6 @@ static inline unsigned long pte_bitop(un return ((value >> rightshift) & mask) << leftshift; } -#ifdef CONFIG_MEM_SOFT_DIRTY - -/* - * Bits _PAGE_BIT_PRESENT, _PAGE_BIT_FILE, _PAGE_BIT_SOFT_DIRTY and - * _PAGE_BIT_PROTNONE are taken, split up the 28 bits of offset - * into this range. - */ -#define PTE_FILE_MAX_BITS 28 -#define PTE_FILE_SHIFT1 (_PAGE_BIT_PRESENT + 1) -#define PTE_FILE_SHIFT2 (_PAGE_BIT_FILE + 1) -#define PTE_FILE_SHIFT3 (_PAGE_BIT_PROTNONE + 1) -#define PTE_FILE_SHIFT4 (_PAGE_BIT_SOFT_DIRTY + 1) -#define PTE_FILE_BITS1 (PTE_FILE_SHIFT2 - PTE_FILE_SHIFT1 - 1) -#define PTE_FILE_BITS2 (PTE_FILE_SHIFT3 - PTE_FILE_SHIFT2 - 1) -#define PTE_FILE_BITS3 (PTE_FILE_SHIFT4 - PTE_FILE_SHIFT3 - 1) - -#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) - -static __always_inline pgoff_t pte_to_pgoff(pte_t pte) -{ - return (pgoff_t) - (pte_bitop(pte.pte_low, PTE_FILE_SHIFT1, PTE_FILE_MASK1, 0) + - pte_bitop(pte.pte_low, PTE_FILE_SHIFT2, PTE_FILE_MASK2, PTE_FILE_LSHIFT2) + - pte_bitop(pte.pte_low, PTE_FILE_SHIFT3, PTE_FILE_MASK3, PTE_FILE_LSHIFT3) + - pte_bitop(pte.pte_low, PTE_FILE_SHIFT4, -1UL, PTE_FILE_LSHIFT4)); -} - -static __always_inline pte_t pgoff_to_pte(pgoff_t off) -{ - return (pte_t){ - .pte_low = - pte_bitop(off, 0, PTE_FILE_MASK1, PTE_FILE_SHIFT1) + - pte_bitop(off, PTE_FILE_LSHIFT2, PTE_FILE_MASK2, PTE_FILE_SHIFT2) + - pte_bitop(off, PTE_FILE_LSHIFT3, PTE_FILE_MASK3, PTE_FILE_SHIFT3) + - pte_bitop(off, PTE_FILE_LSHIFT4, -1UL, PTE_FILE_SHIFT4) + - _PAGE_FILE, - }; -} - -#else /* CONFIG_MEM_SOFT_DIRTY */ - /* * Bits _PAGE_BIT_PRESENT, _PAGE_BIT_FILE and _PAGE_BIT_PROTNONE are taken, * split up the 29 bits of offset into this range. @@ -145,8 +98,6 @@ static __always_inline pte_t pgoff_to_pt }; } -#endif /* CONFIG_MEM_SOFT_DIRTY */ - /* Encode and de-code a swap entry */ #define SWP_TYPE_BITS (_PAGE_BIT_FILE - _PAGE_BIT_PRESENT - 1) #define SWP_OFFSET_SHIFT (_PAGE_BIT_PROTNONE + 1) Index: linux-2.6.git/arch/x86/include/asm/pgtable.h =================================================================== --- linux-2.6.git.orig/arch/x86/include/asm/pgtable.h +++ linux-2.6.git/arch/x86/include/asm/pgtable.h @@ -297,6 +297,7 @@ static inline pmd_t pmd_mknotpresent(pmd return pmd_clear_flags(pmd, _PAGE_PRESENT); } +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY static inline int pte_soft_dirty(pte_t pte) { return pte_flags(pte) & _PAGE_SOFT_DIRTY; @@ -332,6 +333,8 @@ static inline int pte_file_soft_dirty(pt return pte_flags(pte) & _PAGE_SOFT_DIRTY; } +#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */ + /* * Mask out unsupported bits in a present pgprot. Non-present pgprots * can use those bits for other purposes, so leave them be. @@ -865,6 +868,7 @@ static inline void update_mmu_cache_pmd( { } +#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY static inline pte_t pte_swp_mksoft_dirty(pte_t pte) { VM_BUG_ON(pte_present_nonuma(pte)); @@ -882,6 +886,7 @@ static inline pte_t pte_swp_clear_soft_d VM_BUG_ON(pte_present_nonuma(pte)); return pte_clear_flags(pte, _PAGE_SWP_SOFT_DIRTY); } +#endif #include <asm-generic/pgtable.h> #endif /* __ASSEMBLY__ */ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker 2014-04-25 8:10 ` [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker Cyrill Gorcunov 2014-05-05 23:31 ` Andrew Morton @ 2014-05-06 16:28 ` H. Peter Anvin 2014-05-06 17:03 ` Cyrill Gorcunov 1 sibling, 1 reply; 7+ messages in thread From: H. Peter Anvin @ 2014-05-06 16:28 UTC (permalink / raw) To: Cyrill Gorcunov, linux-kernel Cc: linux-mm, torvalds, mgorman, mingo, steven, riel, david.vrabel, akpm, peterz, xemul On 04/25/2014 01:10 AM, Cyrill Gorcunov wrote: > Tracking dirty status on 2 level pages requires very ugly macros > and taking into account how old the machines who can operate > without PAE mode only are, lets drop soft dirty tracker from > them for code simplicity (note I can't drop all the macros > from 2 level pages by now since _PAGE_BIT_PROTNONE and > _PAGE_BIT_FILE are still used even without tracker). > > Linus proposed to completely rip off softdirty support on > x86-32 (even with PAE) and since for CRIU we're not planning > to support native x86-32 mode, lets do that. > > (Softdirty tracker is relatively new feature which mostly used > by CRIU so I don't expect if such API change would cause problems > on userspace). I have to wonder which one is more likely to actually matter on whatever legacy 32-bit are going to remain. This pretty much comes down to what kind of advanced features are going to matter in deep embedded applications in the future: checkpoint/restart or NUMA. My guess is that it is actually checkpoint/restart... How much does it actually simplify to leave this feature in for PAE? I could care less about non-PAE... NX has pretty much killed that off cold. -hpa -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker 2014-05-06 16:28 ` [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker H. Peter Anvin @ 2014-05-06 17:03 ` Cyrill Gorcunov 0 siblings, 0 replies; 7+ messages in thread From: Cyrill Gorcunov @ 2014-05-06 17:03 UTC (permalink / raw) To: H. Peter Anvin Cc: linux-kernel, linux-mm, torvalds, mgorman, mingo, steven, riel, david.vrabel, akpm, peterz, xemul On Tue, May 06, 2014 at 09:28:07AM -0700, H. Peter Anvin wrote: > On 04/25/2014 01:10 AM, Cyrill Gorcunov wrote: > > Tracking dirty status on 2 level pages requires very ugly macros > > and taking into account how old the machines who can operate > > without PAE mode only are, lets drop soft dirty tracker from > > them for code simplicity (note I can't drop all the macros > > from 2 level pages by now since _PAGE_BIT_PROTNONE and > > _PAGE_BIT_FILE are still used even without tracker). > > > > Linus proposed to completely rip off softdirty support on > > x86-32 (even with PAE) and since for CRIU we're not planning > > to support native x86-32 mode, lets do that. > > > > (Softdirty tracker is relatively new feature which mostly used > > by CRIU so I don't expect if such API change would cause problems > > on userspace). > > I have to wonder which one is more likely to actually matter on whatever > legacy 32-bit are going to remain. This pretty much comes down to what > kind of advanced features are going to matter in deep embedded > applications in the future: checkpoint/restart or NUMA. My guess is > that it is actually checkpoint/restart... > > How much does it actually simplify to leave this feature in for PAE? I > could care less about non-PAE... NX has pretty much killed that off cold. At the current state -- not much I would say. Initially the idea was to drop x86-32 and use page-soft-dirty-bit (ie 11) inside swap entries dropping off page-swap-soft-dirty bit completely, this would simplify all the things but eventually I realized that if I do so the number of maximum swap entries will get more shrinked which is inacceptable I think. Thus, currently (ie even with this patches) we can work on x86-32+PAE but desided to drop x86-32 completely to simplify things in future. Peter, deep embedded applications I guess would be working on systems with really small amount of memory installed in a system I suppose and I doubt if they would need c/r? If we deside to leave x86-32+PAE then don't apply this patch, I will need to update it, (The first patch is safe to apply anyway). -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2014-05-06 17:03 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2014-04-25 8:10 [patch 0/2] A few simplifications for softdirty memory tracker code Cyrill Gorcunov 2014-04-25 8:10 ` [patch 1/2] mm: pgtable -- Drop unneeded preprocessor ifdef Cyrill Gorcunov 2014-04-25 8:10 ` [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker Cyrill Gorcunov 2014-05-05 23:31 ` Andrew Morton 2014-05-06 8:25 ` [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker, v2 Cyrill Gorcunov 2014-05-06 16:28 ` [patch 2/2] mm: pgtable -- Require X86_64 for soft-dirty tracker H. Peter Anvin 2014-05-06 17:03 ` Cyrill Gorcunov
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