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[MIPS] Retire flush_icache_page from mm use.

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On the 34K the redundant cache operations were causing excessive stalls
resulting in realtime code running on the second VPE missing its deadline.
For all other platforms this patch is just a significant performance
improvment as illustrated by below benchmark numbers.

Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------------
Host                 OS  Mhz null null      open slct sig  sig  fork exec sh
                             call  I/O stat clos TCP  inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
25Kf      2.6.18-rc4     533 0.49 1.16 7.57 33.4 30.5 1.34 12.4 5497 17.K 54.K
25Kf      2.6.18-rc4-p   533 0.49 1.16 6.68 23.0 30.7 1.36 8.55 5030 16.K 48.K
4Kc       2.6.18-rc4      80 4.21 15.0 131. 289. 261. 16.5 258. 18.K 70.K 227K
4Kc       2.6.18-rc4-p    80 4.34 13.1 128. 285. 262. 18.2 258. 12.K 52.K 176K
34Kc      2.6.18-rc4      40 5.01 14.0 61.6 90.0 477. 17.9 94.7 29.K 108K 342K
34Kc      2.6.18-rc4-p    40 4.98 13.9 61.2 89.7 475. 17.6 93.7 8758 44.K 158K
BCM1480   2.6.18-rc4     700 0.28 0.60 3.68 5.92 16.0 0.78 5.08 931. 3163 15.K
BCM1480   2.6.18-rc4-p   700 0.28 0.61 3.65 5.85 16.0 0.79 5.20 395. 1464 8385
TX49-16K  2.6.18-rc3     197 0.73 2.41 19.0 37.8 82.9 2.94 17.5 4438 14.K 56.K
TX49-16K  2.6.18-rc3-p   197 0.73 2.40 19.9 36.3 82.9 2.94 23.4 2577 9103 38.K
TX49-32K  2.6.18-rc3     396 0.36 1.19 6.80 11.8 41.0 1.46 8.17 2738 8465 32.K
TX49-32K  2.6.18-rc3-p   396 0.36 1.19 6.82 10.2 41.0 1.46 8.18 1330 4638 18.K
    
Original patch by me with enhancements by Atsushi Nemoto.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
This commit is contained in:
Ralf Baechle 2006-08-12 16:40:08 +01:00
parent 13fdd31abe
commit 585fa72493
7 changed files with 28 additions and 19 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
arch/mips/mm/c-r3k.c
View file

@ -335,7 +335,7 @@ void __init r3k_cache_init(void)
flush_cache_mm = r3k_flush_cache_mm;
flush_cache_range = r3k_flush_cache_range;
flush_cache_page = r3k_flush_cache_page;
flush_icache_page = r3k_flush_icache_page;
__flush_icache_page = r3k_flush_icache_page;
flush_icache_range = r3k_flush_icache_range;
flush_cache_sigtramp = r3k_flush_cache_sigtramp;

2
arch/mips/mm/c-r4k.c
View file

@ -1291,7 +1291,7 @@ void __init r4k_cache_init(void)
__flush_cache_all = r4k___flush_cache_all;
flush_cache_mm = r4k_flush_cache_mm;
flush_cache_page = r4k_flush_cache_page;
flush_icache_page = r4k_flush_icache_page;
__flush_icache_page = r4k_flush_icache_page;
flush_cache_range = r4k_flush_cache_range;
flush_cache_sigtramp = r4k_flush_cache_sigtramp;

2
arch/mips/mm/c-sb1.c
View file

@ -520,7 +520,7 @@ void sb1_cache_init(void)
/* These routines are for Icache coherence with the Dcache */
flush_icache_range = sb1_flush_icache_range;
flush_icache_page = sb1_flush_icache_page;
__flush_icache_page = sb1_flush_icache_page;
flush_icache_all = __sb1_flush_icache_all; /* local only */
/* This implies an Icache flush too, so can't be nop'ed */

4
arch/mips/mm/c-tx39.c
View file

@ -382,7 +382,7 @@ void __init tx39_cache_init(void)
flush_cache_mm = (void *) tx39h_flush_icache_all;
flush_cache_range = (void *) tx39h_flush_icache_all;
flush_cache_page = (void *) tx39h_flush_icache_all;
flush_icache_page = (void *) tx39h_flush_icache_all;
__flush_icache_page = (void *) tx39h_flush_icache_all;
flush_icache_range = (void *) tx39h_flush_icache_all;
flush_cache_sigtramp = (void *) tx39h_flush_icache_all;
@ -408,7 +408,7 @@ void __init tx39_cache_init(void)
flush_cache_mm = tx39_flush_cache_mm;
flush_cache_range = tx39_flush_cache_range;
flush_cache_page = tx39_flush_cache_page;
flush_icache_page = tx39_flush_icache_page;
__flush_icache_page = tx39_flush_icache_page;
flush_icache_range = tx39_flush_icache_range;
flush_cache_sigtramp = tx39_flush_cache_sigtramp;

18
arch/mips/mm/cache.c
View file

@ -25,7 +25,7 @@ void (*flush_cache_range)(struct vm_area_struct *vma, unsigned long start,
void (*flush_cache_page)(struct vm_area_struct *vma, unsigned long page,
unsigned long pfn);
void (*flush_icache_range)(unsigned long start, unsigned long end);
void (*flush_icache_page)(struct vm_area_struct *vma, struct page *page);
void (*__flush_icache_page)(struct vm_area_struct *vma, struct page *page);
/* MIPS specific cache operations */
void (*flush_cache_sigtramp)(unsigned long addr);
@ -70,6 +70,8 @@ void __flush_dcache_page(struct page *page)
struct address_space *mapping = page_mapping(page);
unsigned long addr;
if (PageHighMem(page))
return;
if (mapping && !mapping_mapped(mapping)) {
SetPageDcacheDirty(page);
return;
@ -91,16 +93,16 @@ void __update_cache(struct vm_area_struct *vma, unsigned long address,
{
struct page *page;
unsigned long pfn, addr;
int exec = (vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc;
pfn = pte_pfn(pte);
if (pfn_valid(pfn) && (page = pfn_to_page(pfn), page_mapping(page)) &&
Page_dcache_dirty(page)) {
if (pages_do_alias((unsigned long)page_address(page),
address & PAGE_MASK)) {
addr = (unsigned long) page_address(page);
if (unlikely(!pfn_valid(pfn)))
return;
page = pfn_to_page(pfn);
if (page_mapping(page) && Page_dcache_dirty(page)) {
addr = (unsigned long) page_address(page);
if (exec || pages_do_alias(addr, address & PAGE_MASK))
flush_data_cache_page(addr);
}
ClearPageDcacheDirty(page);
}
}

12
include/asm-mips/cacheflush.h
View file

@ -21,7 +21,6 @@
* - flush_cache_range(vma, start, end) flushes a range of pages
* - flush_icache_range(start, end) flush a range of instructions
* - flush_dcache_page(pg) flushes(wback&invalidates) a page for dcache
* - flush_icache_page(vma, pg) flushes(invalidates) a page for icache
*
* MIPS specific flush operations:
*
@ -39,7 +38,7 @@ extern void __flush_dcache_page(struct page *page);
static inline void flush_dcache_page(struct page *page)
{
if (cpu_has_dc_aliases)
if (cpu_has_dc_aliases || !cpu_has_ic_fills_f_dc)
__flush_dcache_page(page);
}
@ -47,8 +46,13 @@ static inline void flush_dcache_page(struct page *page)
#define flush_dcache_mmap_lock(mapping) do { } while (0)
#define flush_dcache_mmap_unlock(mapping) do { } while (0)
extern void (*flush_icache_page)(struct vm_area_struct *vma,
extern void (*__flush_icache_page)(struct vm_area_struct *vma,
struct page *page);
static inline void flush_icache_page(struct vm_area_struct *vma,
struct page *page)
{
}
extern void (*flush_icache_range)(unsigned long start, unsigned long end);
#define flush_cache_vmap(start, end) flush_cache_all()
#define flush_cache_vunmap(start, end) flush_cache_all()
@ -60,7 +64,7 @@ static inline void copy_to_user_page(struct vm_area_struct *vma,
if (cpu_has_dc_aliases)
flush_cache_page(vma, vaddr, page_to_pfn(page));
memcpy(dst, src, len);
flush_icache_page(vma, page);
__flush_icache_page(vma, page);
}
static inline void copy_from_user_page(struct vm_area_struct *vma,

7
include/asm-mips/page.h
View file

@ -34,6 +34,8 @@
#ifndef __ASSEMBLY__
#include <asm/cpu-features.h>
extern void clear_page(void * page);
extern void copy_page(void * to, void * from);
@ -53,7 +55,7 @@ static inline void clear_user_page(void *addr, unsigned long vaddr,
extern void (*flush_data_cache_page)(unsigned long addr);
clear_page(addr);
if (pages_do_alias((unsigned long) addr, vaddr))
if (pages_do_alias((unsigned long) addr, vaddr & PAGE_MASK))
flush_data_cache_page((unsigned long)addr);
}
@ -63,7 +65,8 @@ static inline void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
extern void (*flush_data_cache_page)(unsigned long addr);
copy_page(vto, vfrom);
if (pages_do_alias((unsigned long)vto, vaddr))
if (!cpu_has_ic_fills_f_dc ||
pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
flush_data_cache_page((unsigned long)vto);
}