From 3255aa2eb636a508fc82a73fabbb8aaf2ff23c0f Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 25 Feb 2009 08:21:52 +0100 Subject: x86, mm: pass in 'total' to __copy_from_user_*nocache() Impact: cleanup, enable future change Add a 'total bytes copied' parameter to __copy_from_user_*nocache(), and update all the callsites. The parameter is not used yet - architecture code can use it to more intelligently decide whether the copy should be cached or non-temporal. Cc: Salman Qazi Cc: Nick Piggin Cc: Linus Torvalds Signed-off-by: Ingo Molnar --- arch/x86/include/asm/uaccess_32.h | 4 ++-- arch/x86/include/asm/uaccess_64.h | 5 ++--- 2 files changed, 4 insertions(+), 5 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h index 5e06259e90e..a0ba6138697 100644 --- a/arch/x86/include/asm/uaccess_32.h +++ b/arch/x86/include/asm/uaccess_32.h @@ -157,7 +157,7 @@ __copy_from_user(void *to, const void __user *from, unsigned long n) } static __always_inline unsigned long __copy_from_user_nocache(void *to, - const void __user *from, unsigned long n) + const void __user *from, unsigned long n, unsigned long total) { might_fault(); if (__builtin_constant_p(n)) { @@ -180,7 +180,7 @@ static __always_inline unsigned long __copy_from_user_nocache(void *to, static __always_inline unsigned long __copy_from_user_inatomic_nocache(void *to, const void __user *from, - unsigned long n) + unsigned long n, unsigned long total) { return __copy_from_user_ll_nocache_nozero(to, from, n); } diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 987a2c10fe2..a748253db0c 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -189,7 +189,7 @@ extern long __copy_user_nocache(void *dst, const void __user *src, unsigned size, int zerorest); static inline int __copy_from_user_nocache(void *dst, const void __user *src, - unsigned size) + unsigned size, unsigned long total) { might_sleep(); /* @@ -205,8 +205,7 @@ static inline int __copy_from_user_nocache(void *dst, const void __user *src, } static inline int __copy_from_user_inatomic_nocache(void *dst, - const void __user *src, - unsigned size) + const void __user *src, unsigned size, unsigned total) { if (likely(size >= PAGE_SIZE)) return __copy_user_nocache(dst, src, size, 0); -- cgit v1.2.3 From 95108fa34a83ffd97e0af959e4b28d7c62008781 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 25 Feb 2009 08:22:20 +0100 Subject: x86: usercopy: check for total size when deciding non-temporal cutoff Impact: make more types of copies non-temporal This change makes the following simple fix: 30d697f: x86: fix performance regression in write() syscall A bit more sophisticated: we check the 'total' number of bytes written to decide whether to copy in a cached or a non-temporal way. This will for example cause the tail (modulo 4096 bytes) chunk of a large write() to be non-temporal too - not just the page-sized chunks. Cc: Salman Qazi Cc: Nick Piggin Cc: Linus Torvalds Signed-off-by: Ingo Molnar --- arch/x86/include/asm/uaccess_64.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index a748253db0c..dcaa0404cf7 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -198,7 +198,7 @@ static inline int __copy_from_user_nocache(void *dst, const void __user *src, * non-temporal stores here. Smaller writes get handled * via regular __copy_from_user(): */ - if (likely(size >= PAGE_SIZE)) + if (likely(total >= PAGE_SIZE)) return __copy_user_nocache(dst, src, size, 1); else return __copy_from_user(dst, src, size); @@ -207,7 +207,7 @@ static inline int __copy_from_user_nocache(void *dst, const void __user *src, static inline int __copy_from_user_inatomic_nocache(void *dst, const void __user *src, unsigned size, unsigned total) { - if (likely(size >= PAGE_SIZE)) + if (likely(total >= PAGE_SIZE)) return __copy_user_nocache(dst, src, size, 0); else return __copy_from_user_inatomic(dst, src, size); -- cgit v1.2.3