[kernel] r13510 - in dists/sid/linux-2.6/debian: . config/arm config/armel patches/features/arm patches/series
Martin Michlmayr
tbm at alioth.debian.org
Sun Apr 26 18:52:36 UTC 2009
Author: tbm
Date: Sun Apr 26 18:52:35 2009
New Revision: 13510
Log:
Add performance patches from git.marvell.com
Added:
dists/sid/linux-2.6/debian/patches/features/arm/allow-alternative-copy-user.patch
dists/sid/linux-2.6/debian/patches/features/arm/alternative-copy-user.patch
Modified:
dists/sid/linux-2.6/debian/changelog
dists/sid/linux-2.6/debian/config/arm/config.orion5x
dists/sid/linux-2.6/debian/config/armel/config.kirkwood
dists/sid/linux-2.6/debian/patches/series/4
Modified: dists/sid/linux-2.6/debian/changelog
==============================================================================
--- dists/sid/linux-2.6/debian/changelog Sun Apr 26 17:22:33 2009 (r13509)
+++ dists/sid/linux-2.6/debian/changelog Sun Apr 26 18:52:35 2009 (r13510)
@@ -7,6 +7,10 @@
* Extend erase timeout in M25P80 SPI Flash driver (Peter Horton).
* Add driver for GMT G760A fan speed PWM controller chip.
* [arm/orion5x] Enable SENSORS_G760A.
+ * Add patches from git.marvell.com:
+ - allow for alternative __copy_to_user/__clear_user implementations
+ - alternative copy_to_user/clear_user implementation copy_user
+ * [arm/orion5x, armel/kirkwood] Enable UACCESS_WITH_MEMCPY.
[ dann frazier ]
* [parisc] Fix macro expansion in atomic.h fixing PHONET compilation issue
Modified: dists/sid/linux-2.6/debian/config/arm/config.orion5x
==============================================================================
--- dists/sid/linux-2.6/debian/config/arm/config.orion5x Sun Apr 26 17:22:33 2009 (r13509)
+++ dists/sid/linux-2.6/debian/config/arm/config.orion5x Sun Apr 26 18:52:35 2009 (r13510)
@@ -609,3 +609,5 @@
CONFIG_SENSORS_G760A=m
+CONFIG_UACCESS_WITH_MEMCPY=y
+
Modified: dists/sid/linux-2.6/debian/config/armel/config.kirkwood
==============================================================================
--- dists/sid/linux-2.6/debian/config/armel/config.kirkwood Sun Apr 26 17:22:33 2009 (r13509)
+++ dists/sid/linux-2.6/debian/config/armel/config.kirkwood Sun Apr 26 18:52:35 2009 (r13510)
@@ -631,3 +631,5 @@
##
CONFIG_MTD_M25P80=y
+CONFIG_UACCESS_WITH_MEMCPY=y
+
Added: dists/sid/linux-2.6/debian/patches/features/arm/allow-alternative-copy-user.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux-2.6/debian/patches/features/arm/allow-alternative-copy-user.patch Sun Apr 26 18:52:35 2009 (r13510)
@@ -0,0 +1,63 @@
+From: Nicolas Pitre <nico at cam.org>
+Date: Mon, 9 Mar 2009 02:34:45 +0000 (-0400)
+Subject: [ARM] allow for alternative __copy_to_user/__clear_user implementations
+X-Git-Url: http://git.marvell.com/?p=orion.git;a=commitdiff_plain;h=3e4bd7ea3a16ec3a6f93f62a0d206df5b7f900e9
+
+[ARM] allow for alternative __copy_to_user/__clear_user implementations
+
+This allows for optional alternative implementations of __copy_to_user
+and __clear_user, with a possible runtime fallback to the standard
+version when the alternative provides no gain over that standard
+version. This is done by making the standard __copy_to_user into a weak
+alias for the symbol __copy_to_user_std. Same thing for __clear_user.
+
+Those two functions are particularly good candidates to have alternative
+implementations for, since they rely on the STRT instruction which has
+lower performances than STM instructions on some CPU cores such as
+the ARM1176 and Marvell Feroceon.
+
+Signed-off-by: Nicolas Pitre <nico at marvell.com>
+---
+
+diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
+index 7897464..0da9bc9 100644
+--- a/arch/arm/include/asm/uaccess.h
++++ b/arch/arm/include/asm/uaccess.h
+@@ -386,7 +386,9 @@ do { \
+ #ifdef CONFIG_MMU
+ extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
+ extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
++extern unsigned long __must_check __copy_to_user_std(void __user *to, const void *from, unsigned long n);
+ extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
++extern unsigned long __must_check __clear_user_std(void __user *addr, unsigned long n);
+ #else
+ #define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
+ #define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
+diff --git a/arch/arm/lib/clear_user.S b/arch/arm/lib/clear_user.S
+index 4d6bc71..844f567 100644
+--- a/arch/arm/lib/clear_user.S
++++ b/arch/arm/lib/clear_user.S
+@@ -18,7 +18,8 @@
+ * : sz - number of bytes to clear
+ * Returns : number of bytes NOT cleared
+ */
+-ENTRY(__clear_user)
++ENTRY(__clear_user_std)
++WEAK(__clear_user)
+ stmfd sp!, {r1, lr}
+ mov r2, #0
+ cmp r1, #4
+diff --git a/arch/arm/lib/copy_to_user.S b/arch/arm/lib/copy_to_user.S
+index 22f968b..878820f 100644
+--- a/arch/arm/lib/copy_to_user.S
++++ b/arch/arm/lib/copy_to_user.S
+@@ -86,7 +86,8 @@
+
+ .text
+
+-ENTRY(__copy_to_user)
++ENTRY(__copy_to_user_std)
++WEAK(__copy_to_user)
+
+ #include "copy_template.S"
+
Added: dists/sid/linux-2.6/debian/patches/features/arm/alternative-copy-user.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/sid/linux-2.6/debian/patches/features/arm/alternative-copy-user.patch Sun Apr 26 18:52:35 2009 (r13510)
@@ -0,0 +1,229 @@
+From: Lennert Buytenhek <buytenh at marvell.com>
+Date: Mon, 9 Mar 2009 18:30:09 +0000 (-0400)
+Subject: [ARM] alternative copy_to_user/clear_user implementation
+X-Git-Url: http://git.marvell.com/?p=orion.git;a=commitdiff_plain;h=2d6c3846a588b82d1d6e13ef1afcbef8667ad272
+
+[ARM] alternative copy_to_user/clear_user implementation
+
+This implements {copy_to,clear}_user() by faulting in the userland
+pages and then using the regular kernel mem{cpy,set}() to copy the
+data (while holding the page table lock). This is a win if the regular
+mem{cpy,set}() implementations are faster than the user copy functions,
+which is the case e.g. on Feroceon, where 8-word STMs (which memcpy()
+uses under the right conditions) give significantly higher memory write
+throughput than a sequence of individual 32bit stores.
+
+Here are numbers for page sized buffers on some Feroceon cores:
+
+ - copy_to_user on Orion5x goes from 51 MB/s to 83 MB/s
+ - clear_user on Orion5x goes from 89MB/s to 314MB/s
+ - copy_to_user on Kirkwood goes from 240 MB/s to 356 MB/s
+ - clear_user on Kirkwood goes from 367 MB/s to 1108 MB/s
+ - copy_to_user on Disco-Duo goes from 248 MB/s to 398 MB/s
+ - clear_user on Disco-Duo goes from 328 MB/s to 1741 MB/s
+
+Because the setup cost is non negligible, this is worthwhile only if
+the amount of data to copy is large enough. The operation falls back
+to the standard implementation when the amount of data is below a certain
+treshold. This treshold was determined empirically, however some targets
+could benefit from a lower runtime determined value for optimal results
+eventually.
+
+In the copy_from_user() case, this technique does not provide any
+worthwhile performance gain due to the fact that any kind of read access
+allocates the cache and subsequent 32bit loads are just as fast as the
+equivalent 8-word LDM.
+
+[ Nicolas Pitre came with the idea, Lennert Buytenhek wrote the code. ]
+
+Tested-by: Martin Michlmayr <tbm at cyrius.com>
+Signed-off-by: Lennert Buytenhek <buytenh at marvell.com>
+Signed-off-by: Nicolas Pitre <nico at marvell.com>
+---
+
+diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
+index dbfdf87..0d1c72b 100644
+--- a/arch/arm/Kconfig
++++ b/arch/arm/Kconfig
+@@ -983,6 +983,22 @@ config ALIGNMENT_TRAP
+ correct operation of some network protocols. With an IP-only
+ configuration it is safe to say N, otherwise say Y.
+
++config UACCESS_WITH_MEMCPY
++ bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user() (EXPERIMENTAL)"
++ depends on MMU && EXPERIMENTAL
++ default y if CPU_FEROCEON
++ help
++ Implement faster copy_to_user and clear_user methods for CPU
++ cores where a 8-word STM instruction give significantly higher
++ memory write throughput than a sequence of individual 32bit stores.
++
++ A possible side effect is a slight increase in scheduling latency
++ between threads sharing the same address space if they invoke
++ such copy operations with large buffers.
++
++ However, if the CPU data cache is using a write-allocate mode,
++ this option is unlikely to provide any performance gain.
++
+ endmenu
+
+ menu "Boot options"
+diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
+index 866f84a..030ba72 100644
+--- a/arch/arm/lib/Makefile
++++ b/arch/arm/lib/Makefile
+@@ -29,6 +29,9 @@ else
+ endif
+ endif
+
++# using lib_ here won't override already available weak symbols
++obj-$(CONFIG_UACCESS_WITH_MEMCPY) += uaccess_with_memcpy.o
++
+ lib-$(CONFIG_MMU) += $(mmu-y)
+
+ ifeq ($(CONFIG_CPU_32v3),y)
+diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c
+new file mode 100644
+index 0000000..8bd9fc7
+--- /dev/null
++++ b/arch/arm/lib/uaccess_with_memcpy.c
+@@ -0,0 +1,139 @@
++/*
++ * linux/arch/arm/lib/uaccess_with_memcpy.c
++ *
++ * Copyright (C) 2009 Lennert Buytenhek <buytenh at wantstofly.org>
++ * Copyright (C) 2009 Marvell Semiconductor
++ *
++ * This program is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License version 2 as
++ * published by the Free Software Foundation.
++ */
++
++#include <linux/kernel.h>
++#include <linux/ctype.h>
++#include <linux/uaccess.h>
++#include <linux/rwsem.h>
++#include <linux/mm.h>
++#include <linux/sched.h>
++#include <linux/hardirq.h> /* for in_atomic() */
++#include <asm/current.h>
++#include <asm/page.h>
++
++static int
++pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp)
++{
++ unsigned long addr = (unsigned long)_addr;
++ pgd_t *pgd;
++ pmd_t *pmd;
++ pte_t *pte;
++ spinlock_t *ptl;
++
++ pgd = pgd_offset(current->mm, addr);
++ if (unlikely(pgd_none(*pgd) || pgd_bad(*pgd)))
++ return 0;
++
++ pmd = pmd_offset(pgd, addr);
++ if (unlikely(pmd_none(*pmd) || pmd_bad(*pmd)))
++ return 0;
++
++ pte = pte_offset_map_lock(current->mm, pmd, addr, &ptl);
++ if (unlikely(!pte_present(*pte) || !pte_young(*pte) ||
++ !pte_write(*pte) || !pte_dirty(*pte))) {
++ pte_unmap_unlock(pte, ptl);
++ return 0;
++ }
++
++ *ptep = pte;
++ *ptlp = ptl;
++
++ return 1;
++}
++
++unsigned long
++__copy_to_user(void __user *to, const void *from, unsigned long n)
++{
++ int atomic;
++
++ if (n < 1024)
++ return __copy_to_user_std(to, from, n);
++
++ if (unlikely(segment_eq(get_fs(), KERNEL_DS))) {
++ memcpy((void *)to, from, n);
++ return 0;
++ }
++
++ /* the mmap semaphore is taken only if not in an atomic context */
++ atomic = in_atomic();
++
++ if (!atomic)
++ down_read(¤t->mm->mmap_sem);
++ while (n) {
++ pte_t *pte;
++ spinlock_t *ptl;
++ int tocopy;
++
++ while (!pin_page_for_write(to, &pte, &ptl)) {
++ if (!atomic)
++ up_read(¤t->mm->mmap_sem);
++ if (__put_user(0, (char __user *)to))
++ goto out;
++ if (!atomic)
++ down_read(¤t->mm->mmap_sem);
++ }
++
++ tocopy = (~(unsigned long)to & ~PAGE_MASK) + 1;
++ if (tocopy > n)
++ tocopy = n;
++
++ memcpy((void *)to, from, tocopy);
++ to += tocopy;
++ from += tocopy;
++ n -= tocopy;
++
++ pte_unmap_unlock(pte, ptl);
++ }
++ if (!atomic)
++ up_read(¤t->mm->mmap_sem);
++
++out:
++ return n;
++}
++
++unsigned long __clear_user(void __user *addr, unsigned long n)
++{
++ if (n < 256)
++ return __clear_user_std(addr, n);
++
++ if (unlikely(segment_eq(get_fs(), KERNEL_DS))) {
++ memset((void *)addr, 0, n);
++ return 0;
++ }
++
++ down_read(¤t->mm->mmap_sem);
++ while (n) {
++ pte_t *pte;
++ spinlock_t *ptl;
++ int tocopy;
++
++ while (!pin_page_for_write(addr, &pte, &ptl)) {
++ up_read(¤t->mm->mmap_sem);
++ if (__put_user(0, (char __user *)addr))
++ goto out;
++ down_read(¤t->mm->mmap_sem);
++ }
++
++ tocopy = (~(unsigned long)addr & ~PAGE_MASK) + 1;
++ if (tocopy > n)
++ tocopy = n;
++
++ memset((void *)addr, 0, tocopy);
++ addr += tocopy;
++ n -= tocopy;
++
++ pte_unmap_unlock(pte, ptl);
++ }
++ up_read(¤t->mm->mmap_sem);
++
++out:
++ return n;
++}
Modified: dists/sid/linux-2.6/debian/patches/series/4
==============================================================================
--- dists/sid/linux-2.6/debian/patches/series/4 Sun Apr 26 17:22:33 2009 (r13509)
+++ dists/sid/linux-2.6/debian/patches/series/4 Sun Apr 26 18:52:35 2009 (r13510)
@@ -3,3 +3,5 @@
+ bugfix/parisc/fix-macro-expansion-in-atomic.h.patch
+ bugfix/all/btrfs-fix-__ucmpdi2-compile-bug.patch
+ features/arm/g760a.patch
++ features/arm/allow-alternative-copy-user.patch
++ features/arm/alternative-copy-user.patch
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