From: Huang Pei <huangpei@loongson.cn>
To: Thomas Bogendoerfer <tsbogend@alpha.franken.de>, ambrosehua@gmail.com
Cc: Bibo Mao <maobibo@loongson.cn>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mips@vger.kernel.org, linux-arch@vger.kernel.org,
linux-mm@kvack.org, Jiaxun Yang <jiaxun.yang@flygoat.com>,
Paul Burton <paulburton@kernel.org>,
Li Xuefeng <lixuefeng@loongson.cn>,
Yang Tiezhu <yangtiezhu@loongson.cn>,
Gao Juxin <gaojuxin@loongson.cn>,
Fuxin Zhang <zhangfx@lemote.com>, Huacai Chen <chenhc@lemote.com>
Subject: Re: [PATCH V3] MIPS: make userspace mapping young by default
Date: Mon, 28 Sep 2020 14:39:12 +0800 [thread overview]
Message-ID: <20200928063912.5ctr7j2eap4q4jf7@ambrosehua-HP-xw6600-Workstation> (raw)
In-Reply-To: <20200919074731.22372-1-huangpei@loongson.cn>
On Sat, Sep 19, 2020 at 03:47:31PM +0800, Huang Pei wrote:
Ping?
> MIPS page fault path take 3 exceptions (1 TLB Miss + 2 TLB Invalid), but
> the second TLB Invalid exception is just triggered by __update_tlb from
> do_page_fault writing tlb without _PAGE_VALID set. With this patch, it
> only take 1 TLB Miss + 1 TLB Invalid exceptions
>
> This version removes pte_sw_mkyoung without polluting MM code and makes
> page fault delay of MIPS on par with other architecture and covers both
> no-RIXI and RIXI MIPS CPUS
>
> [1]: https://lkml.kernel.org/lkml/1591416169-26666-1-git-send-email
> -maobibo@loongson.cn/
> ---
> V3:
> - reformat with whitespace cleaned up following Thomas's advice
> V2:
> - remove unused asm-generic definition of pte_sw_mkyoung following Mao's
> advice
> ---
> Co-developed-by: Huang Pei <huangpei@loongson.cn>
> Signed-off-by: Huang Pei <huangpei@loongson.cn>
> Co-developed-by: Bibo Mao <maobibo@loonson.cn>
> ---
> arch/mips/include/asm/pgtable.h | 10 ++++------
> arch/mips/mm/cache.c | 25 +++++++++++++------------
> include/linux/pgtable.h | 8 --------
> mm/memory.c | 3 ---
> 4 files changed, 17 insertions(+), 29 deletions(-)
>
> diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
> index dd7a0f552cac..931fb35730f0 100644
> --- a/arch/mips/include/asm/pgtable.h
> +++ b/arch/mips/include/asm/pgtable.h
> @@ -27,11 +27,11 @@ struct vm_area_struct;
>
> #define PAGE_NONE __pgprot(_PAGE_PRESENT | _PAGE_NO_READ | \
> _page_cachable_default)
> -#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_WRITE | \
> - _page_cachable_default)
> +#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_WRITE | \
> + __READABLE | _page_cachable_default)
> #define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_NO_EXEC | \
> - _page_cachable_default)
> -#define PAGE_READONLY __pgprot(_PAGE_PRESENT | \
> + __READABLE | _page_cachable_default)
> +#define PAGE_READONLY __pgprot(_PAGE_PRESENT | __READABLE | \
> _page_cachable_default)
> #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
> _PAGE_GLOBAL | _page_cachable_default)
> @@ -414,8 +414,6 @@ static inline pte_t pte_mkyoung(pte_t pte)
> return pte;
> }
>
> -#define pte_sw_mkyoung pte_mkyoung
> -
> #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
> static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_HUGE; }
>
> diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
> index 3e81ba000096..ed75f2871aad 100644
> --- a/arch/mips/mm/cache.c
> +++ b/arch/mips/mm/cache.c
> @@ -159,22 +159,23 @@ static inline void setup_protection_map(void)
> {
> if (cpu_has_rixi) {
> protection_map[0] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
> - protection_map[1] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
> + protection_map[1] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE);
> protection_map[2] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
> - protection_map[3] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
> - protection_map[4] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
> - protection_map[5] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
> - protection_map[6] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
> - protection_map[7] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
> + protection_map[3] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE);
> + protection_map[4] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
> + protection_map[5] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
> + protection_map[6] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
> + protection_map[7] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
>
> protection_map[8] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
> - protection_map[9] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
> + protection_map[9] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE);
> protection_map[10] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | _PAGE_NO_READ);
> - protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE);
> - protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
> - protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
> - protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);
> - protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);
> + protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | __READABLE);
> + protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
> + protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE);
> + protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE);
> + protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE);
> +
>
> } else {
> protection_map[0] = PAGE_NONE;
> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> index e8cbc2e795d5..ef9c5fa8673e 100644
> --- a/include/linux/pgtable.h
> +++ b/include/linux/pgtable.h
> @@ -377,14 +377,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
> * To be differentiate with macro pte_mkyoung, this macro is used on platforms
> * where software maintains page access bit.
> */
> -#ifndef pte_sw_mkyoung
> -static inline pte_t pte_sw_mkyoung(pte_t pte)
> -{
> - return pte;
> -}
> -#define pte_sw_mkyoung pte_sw_mkyoung
> -#endif
> -
> #ifndef pte_savedwrite
> #define pte_savedwrite pte_write
> #endif
> diff --git a/mm/memory.c b/mm/memory.c
> index 602f4283122f..5100ab5bcf77 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -2705,7 +2705,6 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
> }
> flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte));
> entry = mk_pte(new_page, vma->vm_page_prot);
> - entry = pte_sw_mkyoung(entry);
> entry = maybe_mkwrite(pte_mkdirty(entry), vma);
> /*
> * Clear the pte entry and flush it first, before updating the
> @@ -3386,7 +3385,6 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
> __SetPageUptodate(page);
>
> entry = mk_pte(page, vma->vm_page_prot);
> - entry = pte_sw_mkyoung(entry);
> if (vma->vm_flags & VM_WRITE)
> entry = pte_mkwrite(pte_mkdirty(entry));
>
> @@ -3661,7 +3659,6 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct page *page)
>
> flush_icache_page(vma, page);
> entry = mk_pte(page, vma->vm_page_prot);
> - entry = pte_sw_mkyoung(entry);
> if (write)
> entry = maybe_mkwrite(pte_mkdirty(entry), vma);
> /* copy-on-write page */
> --
> 2.17.1
>
next prev parent reply other threads:[~2020-09-28 6:39 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-19 7:47 Huang Pei
2020-09-28 6:39 ` Huang Pei [this message]
2020-10-02 12:35 ` Thomas Bogendoerfer
2020-10-08 3:30 ` Huang Pei
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