From: Lars Persson <lars.persson@axis.com>
To: linux-mips@linux-mips.org, ralf@linux-mips.org, paul.burton@imgtec.com
Cc: linux-kernel@vger.kernel.org, Lars Persson <larper@axis.com>
Subject: [PATCH 1/2] Revert "MIPS: Remove race window in page fault handling"
Date: Thu, 26 Feb 2015 14:16:02 +0100 [thread overview]
Message-ID: <1424956563-29535-2-git-send-email-larper@axis.com> (raw)
In-Reply-To: <1424956563-29535-1-git-send-email-larper@axis.com>
Revert commit 2a4a8b1e5d9d ("MIPS: Remove race window in page fault
handling") because it increased the number of flushed dcache pages and
became a performance problem for some workloads.
Signed-off-by: Lars Persson <larper@axis.com>
---
arch/mips/include/asm/pgtable.h | 10 ++++++----
arch/mips/mm/cache.c | 27 ++++++++-------------------
2 files changed, 14 insertions(+), 23 deletions(-)
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index bef782c..bd6d1cf 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -127,12 +127,9 @@ do { \
} \
} while(0)
-
-extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
- pte_t pteval);
-
#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
+
#define pte_none(pte) (!(((pte).pte_low | (pte).pte_high) & ~_PAGE_GLOBAL))
#define pte_present(pte) ((pte).pte_low & _PAGE_PRESENT)
@@ -154,6 +151,7 @@ static inline void set_pte(pte_t *ptep, pte_t pte)
}
}
}
+#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
@@ -192,6 +190,7 @@ static inline void set_pte(pte_t *ptep, pte_t pteval)
}
#endif
}
+#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
@@ -407,12 +406,15 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
pte_t pte);
+extern void __update_cache(struct vm_area_struct *vma, unsigned long address,
+ pte_t pte);
static inline void update_mmu_cache(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep)
{
pte_t pte = *ptep;
__update_tlb(vma, address, pte);
+ __update_cache(vma, address, pte);
}
static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
index 7e3ea77..f7b91d3 100644
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -119,36 +119,25 @@ void __flush_anon_page(struct page *page, unsigned long vmaddr)
EXPORT_SYMBOL(__flush_anon_page);
-static void mips_flush_dcache_from_pte(pte_t pteval, unsigned long address)
+void __update_cache(struct vm_area_struct *vma, unsigned long address,
+ pte_t pte)
{
struct page *page;
- unsigned long pfn = pte_pfn(pteval);
+ unsigned long pfn, addr;
+ int exec = (vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc;
+ pfn = pte_pfn(pte);
if (unlikely(!pfn_valid(pfn)))
return;
-
page = pfn_to_page(pfn);
if (page_mapping(page) && Page_dcache_dirty(page)) {
- unsigned long page_addr = (unsigned long) page_address(page);
-
- if (!cpu_has_ic_fills_f_dc ||
- pages_do_alias(page_addr, address & PAGE_MASK))
- flush_data_cache_page(page_addr);
+ addr = (unsigned long) page_address(page);
+ if (exec || pages_do_alias(addr, address & PAGE_MASK))
+ flush_data_cache_page(addr);
ClearPageDcacheDirty(page);
}
}
-void set_pte_at(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pteval)
-{
- if (cpu_has_dc_aliases || !cpu_has_ic_fills_f_dc) {
- if (pte_present(pteval))
- mips_flush_dcache_from_pte(pteval, addr);
- }
-
- set_pte(ptep, pteval);
-}
-
unsigned long _page_cachable_default;
EXPORT_SYMBOL(_page_cachable_default);
--
1.7.10.4
next prev parent reply other threads:[~2015-02-26 13:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-26 13:16 [PATCH 0/2] New fix for icache coherency race Lars Persson
2015-02-26 13:16 ` Lars Persson [this message]
2015-02-26 13:16 ` [PATCH 2/2] MIPS: Fix race condition in lazy cache flushing Lars Persson
2015-04-08 22:53 ` [PATCH 0/2] New fix for icache coherency race Paul Burton
2015-04-09 10:54 ` Lars Persson
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