From: Peter Zijlstra <peterz@infradead.org>
To: Zhenyu Ye <yezhenyu2@huawei.com>
Cc: mark.rutland@arm.com, will@kernel.org, catalin.marinas@arm.com,
aneesh.kumar@linux.ibm.com, akpm@linux-foundation.org,
npiggin@gmail.com, arnd@arndb.de, rostedt@goodmis.org,
maz@kernel.org, suzuki.poulose@arm.com, tglx@linutronix.de,
yuzhao@google.com, Dave.Martin@arm.com, steven.price@arm.com,
broonie@kernel.org, guohanjun@huawei.com, corbet@lwn.net,
vgupta@synopsys.com, tony.luck@intel.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linux-mm@kvack.org, arm@kernel.org, xiexiangyou@huawei.com,
prime.zeng@hisilicon.com, zhangshaokun@hisilicon.com,
kuhn.chenqun@huawei.com
Subject: Re: [RFC PATCH v5 4/8] mm: tlb: Pass struct mmu_gather to flush_pmd_tlb_range
Date: Wed, 1 Apr 2020 14:20:04 +0200 [thread overview]
Message-ID: <20200401122004.GE20713@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <fe12101e-8efe-22ad-0258-e6aeafc798cc@huawei.com>
On Wed, Apr 01, 2020 at 04:51:15PM +0800, Zhenyu Ye wrote:
> On 2020/3/31 23:13, Peter Zijlstra wrote:
> > Instead of trying to retro-fit flush_*tlb_range() to take an mmu_gather
> > parameter, please replace them out-right.
> >
>
> I'm sorry that I'm not sure what "replace them out-right" means. Do you
> mean that I should define flush_*_tlb_range like this?
>
> #define flush_pmd_tlb_range(vma, addr, end) \
> do { \
> struct mmu_gather tlb; \
> tlb_gather_mmu(&tlb, (vma)->vm_mm, addr, end); \
> tlba.cleared_pmds = 1; \
> flush_tlb_range(&tlb, vma, addr, end); \
> tlb_finish_mmu(&tlb, addr, end); \
> } while (0)
>
I was thinking to remove flush_*tlb_range() entirely (from generic
code).
And specifically to not use them like the above; instead extend the
mmu_gather API.
Specifically, if you wanted to express flush_pmd_tlb_range() in mmu
gather, you'd write it like:
static inline void flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long addr, unsigned long end)
{
struct mmu_gather tlb;
tlb_gather_mmu(&tlb, vma->vm_mm, addr, end);
tlb_start_vma(&tlb, vma);
tlb.cleared_pmds = 1;
__tlb_adjust_range(addr, end - addr);
tlb_end_vma(&tlb, vma);
tlb_finish_mmu(&tlb, addr, end);
}
Except of course, that the code between start_vma and end_vma is not a
proper mmu_gather API.
So maybe add:
tlb_flush_{pte,pmd,pud,p4d}_range()
Then we can write:
static inline void flush_XXX_tlb_range(struct vm_area_struct *vma, unsigned long addr, unsigned long end)
{
struct mmu_gather tlb;
tlb_gather_mmu(&tlb, vma->vm_mm, addr, end);
tlb_start_vma(&tlb, vma);
tlb_flush_XXX_range(&tlb, addr, end - addr);
tlb_end_vma(&tlb, vma);
tlb_finish_mmu(&tlb, addr, end);
}
But when I look at the output of:
git grep flush_.*tlb_range -- :^arch/
I doubt it makes sense to provide wrappers like the above.
( Also, we should probably remove the (addr, end) arguments from
tlb_finish_mmu(), Will? )
---
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index f391f6b500b4..be5452a8efaa 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -511,6 +511,34 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
}
#endif
+static inline void tlb_flush_pte_range(struct mmu_gather *tlb,
+ unsigned long address, unsigned long size)
+{
+ __tlb_adjust_range(tlb, address, size);
+ tlb->cleared_ptes = 1;
+}
+
+static inline void tlb_flush_pmd_range(struct mmu_gather *tlb,
+ unsigned long address, unsigned long size)
+{
+ __tlb_adjust_range(tlb, address, size);
+ tlb->cleared_pmds = 1;
+}
+
+static inline void tlb_flush_pud_range(struct mmu_gather *tlb,
+ unsigned long address, unsigned long size)
+{
+ __tlb_adjust_range(tlb, address, size);
+ tlb->cleared_puds = 1;
+}
+
+static inline void tlb_flush_p4d_range(struct mmu_gather *tlb,
+ unsigned long address, unsigned long size)
+{
+ __tlb_adjust_range(tlb, address, size);
+ tlb->cleared_p4ds = 1;
+}
+
#ifndef __tlb_remove_tlb_entry
#define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0)
#endif
@@ -524,8 +552,7 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
*/
#define tlb_remove_tlb_entry(tlb, ptep, address) \
do { \
- __tlb_adjust_range(tlb, address, PAGE_SIZE); \
- tlb->cleared_ptes = 1; \
+ tlb_flush_pte_range(tlb, address, PAGE_SIZE); \
__tlb_remove_tlb_entry(tlb, ptep, address); \
} while (0)
@@ -550,8 +577,7 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
#define tlb_remove_pmd_tlb_entry(tlb, pmdp, address) \
do { \
- __tlb_adjust_range(tlb, address, HPAGE_PMD_SIZE); \
- tlb->cleared_pmds = 1; \
+ tlb_flush_pmd_range(tlb, address, HPAGE_PMD_SIZE); \
__tlb_remove_pmd_tlb_entry(tlb, pmdp, address); \
} while (0)
@@ -565,8 +591,7 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
#define tlb_remove_pud_tlb_entry(tlb, pudp, address) \
do { \
- __tlb_adjust_range(tlb, address, HPAGE_PUD_SIZE); \
- tlb->cleared_puds = 1; \
+ tlb_flush_pud_range(tlb, address, HPAGE_PUD_SIZE); \
__tlb_remove_pud_tlb_entry(tlb, pudp, address); \
} while (0)
next prev parent reply other threads:[~2020-04-01 12:20 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-31 14:29 [RFC PATCH v5 0/8] arm64: tlb: add support for TTL feature Zhenyu Ye
2020-03-31 14:29 ` [RFC PATCH v5 1/8] arm64: Detect the ARMv8.4 " Zhenyu Ye
2020-03-31 14:29 ` [RFC PATCH v5 2/8] arm64: Add level-hinted TLB invalidation helper Zhenyu Ye
2020-03-31 14:29 ` [RFC PATCH v5 3/8] arm64: Add tlbi_user_level " Zhenyu Ye
2020-03-31 14:29 ` [RFC PATCH v5 4/8] mm: tlb: Pass struct mmu_gather to flush_pmd_tlb_range Zhenyu Ye
2020-03-31 15:13 ` Peter Zijlstra
2020-04-01 8:51 ` Zhenyu Ye
2020-04-01 12:20 ` Peter Zijlstra [this message]
2020-04-02 11:24 ` Zhenyu Ye
2020-04-02 16:38 ` Peter Zijlstra
2020-04-03 5:14 ` Zhenyu Ye
2020-04-08 9:00 ` Zhenyu Ye
2020-03-31 14:29 ` [RFC PATCH v5 5/8] mm: tlb: Pass struct mmu_gather to flush_pud_tlb_range Zhenyu Ye
2020-03-31 14:29 ` [RFC PATCH v5 6/8] mm: tlb: Pass struct mmu_gather to flush_hugetlb_tlb_range Zhenyu Ye
2020-03-31 14:29 ` [RFC PATCH v5 7/8] mm: tlb: Pass struct mmu_gather to flush_tlb_range Zhenyu Ye
2020-03-31 14:29 ` [RFC PATCH v5 8/8] arm64: tlb: Set the TTL field in flush_tlb_range Zhenyu Ye
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