<snip>
>
> I do not like overwriting gfp flags like that. It is just ugly and error
> prone. A more proper way would be to handle that at the layer we play
> with __GFP_THISNODE. The resulting diff is larger though.
This makes sense to me.
>
> If there is a general concensus that this is growing too complicated
> then Andrea's patch (the second variant to overwrite gfp mask) is much
> simpler of course but I really detest the subtle gfp rewriting. I still
> believe that all the nasty details should be covered at the single
> place.
>
>
> diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
> index 5228c62af416..bac395f1d00a 100644
> --- a/include/linux/mempolicy.h
> +++ b/include/linux/mempolicy.h
> @@ -139,6 +139,8 @@ struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
> struct mempolicy *get_task_policy(struct task_struct *p);
> struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
> unsigned long addr);
> +struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
> + unsigned long addr);
> bool vma_policy_mof(struct vm_area_struct *vma);
>
> extern void numa_default_policy(void);
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index a703c23f8bab..94472bf9a31b 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -629,21 +629,30 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
> * available
> * never: never stall for any thp allocation
> */
> -static inline gfp_t alloc_hugepage_direct_gfpmask(struct vm_area_struct *vma)
> +static inline gfp_t alloc_hugepage_direct_gfpmask(struct vm_area_struct *vma, unsigned long addr)
> {
> const bool vma_madvised = !!(vma->vm_flags & VM_HUGEPAGE);
> + gfp_t this_node = 0;
> + struct mempolicy *pol;
> +
> +#ifdef CONFIG_NUMA
> + /* __GFP_THISNODE makes sense only if there is no explicit binding */
> + pol = get_vma_policy(vma, addr);
> + if (pol->mode != MPOL_BIND)
> + this_node = __GFP_THISNODE;
> +#endif
>
> if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags))
> - return GFP_TRANSHUGE | (vma_madvised ? 0 : __GFP_NORETRY | __GFP_THISNODE);
> + return GFP_TRANSHUGE | (vma_madvised ? 0 : __GFP_NORETRY | this_node);
> if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags))
> - return GFP_TRANSHUGE_LIGHT | __GFP_KSWAPD_RECLAIM | __GFP_THISNODE;
> + return GFP_TRANSHUGE_LIGHT | __GFP_KSWAPD_RECLAIM | this_node;
> if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags))
> return GFP_TRANSHUGE_LIGHT | (vma_madvised ? __GFP_DIRECT_RECLAIM :
> - __GFP_KSWAPD_RECLAIM | __GFP_THISNODE);
> + __GFP_KSWAPD_RECLAIM | this_node);
> if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags))
> return GFP_TRANSHUGE_LIGHT | (vma_madvised ? __GFP_DIRECT_RECLAIM :
> - __GFP_THISNODE);
> - return GFP_TRANSHUGE_LIGHT | __GFP_THISNODE;
> + this_node);
> + return GFP_TRANSHUGE_LIGHT | this_node;
> }
>
> /* Caller must hold page table lock. */
> @@ -715,7 +724,7 @@ vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf)
> pte_free(vma->vm_mm, pgtable);
> return ret;
> }
> - gfp = alloc_hugepage_direct_gfpmask(vma);
> + gfp = alloc_hugepage_direct_gfpmask(vma, haddr);
> page = alloc_hugepage_vma(gfp, vma, haddr, HPAGE_PMD_ORDER);
> if (unlikely(!page)) {
> count_vm_event(THP_FAULT_FALLBACK);
> @@ -1290,7 +1299,7 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
> alloc:
> if (transparent_hugepage_enabled(vma) &&
> !transparent_hugepage_debug_cow()) {
> - huge_gfp = alloc_hugepage_direct_gfpmask(vma);
> + huge_gfp = alloc_hugepage_direct_gfpmask(vma, haddr);
> new_page = alloc_hugepage_vma(huge_gfp, vma, haddr, HPAGE_PMD_ORDER);
> } else
> new_page = NULL;
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 9f0800885613..75bbfc3d6233 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -1648,7 +1648,7 @@ struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
> * freeing by another task. It is the caller's responsibility to free the
> * extra reference for shared policies.
> */
> -static struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
> +struct mempolicy *get_vma_policy(struct vm_area_struct *vma,
> unsigned long addr)
> {
> struct mempolicy *pol = __get_vma_policy(vma, addr);
The warning goes away with this change. I am OK with this patch (plus the original one you sent out,
which could be merged with this one).
Thanks.
—
Best Regards,
Yan Zi
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