Re: [PATCH] mm/damon: Add access checking for hugetlb pages

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, 15 Dec 2021 23:23:25 +0800 Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> wrote:

> The process's VMAs can be mapped by hugetlb page, but now the DAMON
> did not implement the access checking for hugetlb pte, so we can not
> get the actual access count like below if a process VMAs were mapped
> by hugetlb.
> 
> damon_aggregated: target_id=18446614368406014464
> nr_regions=12 4194304-5476352: 0 545
> damon_aggregated: target_id=18446614368406014464
> nr_regions=12 140662370467840-140662372970496: 0 545
> damon_aggregated: target_id=18446614368406014464
> nr_regions=12 140662372970496-140662375460864: 0 545
> damon_aggregated: target_id=18446614368406014464
> nr_regions=12 140662375460864-140662377951232: 0 545
> damon_aggregated: target_id=18446614368406014464
> nr_regions=12 140662377951232-140662380449792: 0 545
> damon_aggregated: target_id=18446614368406014464
> nr_regions=12 140662380449792-140662382944256: 0 545
> ......
> 
> Thus this patch adds hugetlb access checking support, with this patch
> we can see below VMA mapped by hugetlb access count.
> 
> damon_aggregated: target_id=18446613056935405824
> nr_regions=12 140296486649856-140296489914368: 1 3
> damon_aggregated: target_id=18446613056935405824
> nr_regions=12 140296489914368-140296492978176: 1 3
> damon_aggregated: target_id=18446613056935405824
> nr_regions=12 140296492978176-140296495439872: 1 3
> damon_aggregated: target_id=18446613056935405824
> nr_regions=12 140296495439872-140296498311168: 1 3
> damon_aggregated: target_id=18446613056935405824
> nr_regions=12 140296498311168-140296501198848: 1 3
> damon_aggregated: target_id=18446613056935405824
> nr_regions=12 140296501198848-140296504320000: 1 3
> damon_aggregated: target_id=18446613056935405824
> nr_regions=12 140296504320000-140296507568128: 1 2
> ......

Thank you for this patch!

> 
> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
> ---
>  mm/damon/prmtv-common.c | 37 ++++++++++++++++++++++++++++
>  mm/damon/prmtv-common.h | 11 +++++++++
>  mm/damon/vaddr.c        | 65 +++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 113 insertions(+)
> 
> diff --git a/mm/damon/prmtv-common.c b/mm/damon/prmtv-common.c
> index 92a04f5..155afb8 100644
> --- a/mm/damon/prmtv-common.c
> +++ b/mm/damon/prmtv-common.c
> @@ -9,6 +9,7 @@
>  #include <linux/page_idle.h>
>  #include <linux/pagemap.h>
>  #include <linux/rmap.h>
> +#include <linux/hugetlb.h>
>  
>  #include "prmtv-common.h"
>  
> @@ -86,6 +87,42 @@ void damon_pmdp_mkold(pmd_t *pmd, struct mm_struct *mm, unsigned long addr)
>  #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
>  }
>  
> +#ifdef CONFIG_HUGETLB_PAGE
> +void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm,
> +			 struct vm_area_struct *vma, unsigned long addr)
> +{
> +	bool referenced = false;
> +	struct hstate *h = hstate_vma(vma);
> +	pte_t entry;
> +	struct page *page;
> +
> +	entry = huge_ptep_get(pte);
> +	page = pte_page(entry);

Could we do these assignments in above definition part like this?

    pte_t entry = huge_ptep_get(pte);
    struct page *page = pte_page(entry);

> +	if (!page)
> +		return;
> +
> +	get_page(page);
> +
> +	if (pte_young(entry)) {
> +		referenced = true;
> +		entry = pte_mkold(entry);
> +		huge_ptep_set_access_flags(vma, addr, pte, entry,
> +					   vma->vm_flags & VM_WRITE);
> +	}
> +
> +#ifdef CONFIG_MMU_NOTIFIER
> +	if (mmu_notifier_clear_young(mm, addr, addr + huge_page_size(h)))
> +		referenced = true;
> +#endif /* CONFIG_MMU_NOTIFIER */
> +
> +	if (referenced)
> +		set_page_young(page);
> +
> +	set_page_idle(page);
> +	put_page(page);
> +}
> +#endif
> +
>  #define DAMON_MAX_SUBSCORE	(100)
>  #define DAMON_MAX_AGE_IN_LOG	(32)
>  
> diff --git a/mm/damon/prmtv-common.h b/mm/damon/prmtv-common.h
> index e790cb5..65efcb7 100644
> --- a/mm/damon/prmtv-common.h
> +++ b/mm/damon/prmtv-common.h
> @@ -12,5 +12,16 @@
>  void damon_ptep_mkold(pte_t *pte, struct mm_struct *mm, unsigned long addr);
>  void damon_pmdp_mkold(pmd_t *pmd, struct mm_struct *mm, unsigned long addr);
>  
> +#ifdef CONFIG_HUGETLB_PAGE
> +void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm,
> +			 struct vm_area_struct *vma, unsigned long addr);
> +#else
> +static inline void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm,
> +				       struct vm_area_struct *vma,
> +				       unsigned long addr)
> +{
> +}
> +#endif
> +

Seems damon_hugetlb_mkold() is called from only vaddr.c.  Could you move the
definition into vaddr.c and remove this change in prmtv-common.h?

>  int damon_pageout_score(struct damon_ctx *c, struct damon_region *r,
>  			struct damos *s);
> diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
> index 78ff2bc..ee116e5 100644
> --- a/mm/damon/vaddr.c
> +++ b/mm/damon/vaddr.c
> @@ -14,6 +14,7 @@
>  #include <linux/page_idle.h>
>  #include <linux/pagewalk.h>
>  #include <linux/sched/mm.h>
> +#include <linux/hugetlb.h>
>  
>  #include "prmtv-common.h"
>  
> @@ -386,8 +387,33 @@ static int damon_mkold_pmd_entry(pmd_t *pmd, unsigned long addr,
>  	return 0;
>  }
>  
> +#ifdef CONFIG_HUGETLB_PAGE
> +static int damon_mkold_hugetlb_entry(pte_t *pte, unsigned long hmask,
> +				     unsigned long addr, unsigned long end,
> +				     struct mm_walk *walk)
> +{
> +	struct hstate *h = hstate_vma(walk->vma);
> +	spinlock_t *ptl;
> +	pte_t entry;
> +
> +	ptl = huge_pte_lock(h, walk->mm, pte);
> +	entry = huge_ptep_get(pte);

Could we do above assignments in the variables definitions?

> +	if (!pte_present(entry))
> +		goto out;
> +
> +	damon_hugetlb_mkold(pte, walk->mm, walk->vma, addr);
> +
> +out:
> +	spin_unlock(ptl);
> +	return 0;
> +}
> +#else
> +#define damon_mkold_hugetlb_entry NULL
> +#endif
> +
>  static const struct mm_walk_ops damon_mkold_ops = {
>  	.pmd_entry = damon_mkold_pmd_entry,
> +	.hugetlb_entry = damon_mkold_hugetlb_entry,
>  };
>  
>  static void damon_va_mkold(struct mm_struct *mm, unsigned long addr)
> @@ -482,8 +508,47 @@ static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr,
>  	return 0;
>  }
>  
> +#ifdef CONFIG_HUGETLB_PAGE
> +static int damon_young_hugetlb_entry(pte_t *pte, unsigned long hmask,
> +				     unsigned long addr, unsigned long end,
> +				     struct mm_walk *walk)
> +{
> +	struct damon_young_walk_private *priv = walk->private;
> +	struct hstate *h = hstate_vma(walk->vma);
> +	struct page *page;
> +	spinlock_t *ptl;
> +	pte_t entry;
> +
> +	ptl = huge_pte_lock(h, walk->mm, pte);
> +	entry = huge_ptep_get(pte);

Could we do these assignments in the above variables definitions?


Thanks,
SJ

> +	if (!pte_present(entry))
> +		goto out;
> +
> +	page = pte_page(entry);
> +	if (!page)
> +		goto out;
> +
> +	get_page(page);
> +
> +	if (pte_young(entry) || !page_is_idle(page) ||
> +	    mmu_notifier_test_young(walk->mm, addr)) {
> +		*priv->page_sz = huge_page_size(h);
> +		priv->young = true;
> +	}
> +
> +	put_page(page);
> +
> +out:
> +	spin_unlock(ptl);
> +	return 0;
> +}
> +#else
> +#define damon_young_hugetlb_entry NULL
> +#endif
> +
>  static const struct mm_walk_ops damon_young_ops = {
>  	.pmd_entry = damon_young_pmd_entry,
> +	.hugetlb_entry = damon_young_hugetlb_entry,
>  };
>  
>  static bool damon_va_young(struct mm_struct *mm, unsigned long addr,
> -- 
> 1.8.3.1




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux