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Subject: Re: [PATCH 4/6] mm cma: rename PF_MEMALLOC_NOCMA to
 PF_MEMALLOC_NOMOVABLE
To:     Pavel Tatashin <pasha.tatashin@soleen.com>,
        <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
        <akpm@linux-foundation.org>, <vbabka@suse.cz>, <mhocko@suse.com>,
        <david@redhat.com>, <osalvador@suse.de>,
        <dan.j.williams@intel.com>, <sashal@kernel.org>,
        <tyhicks@linux.microsoft.com>, <iamjoonsoo.kim@lge.com>,
        <mike.kravetz@oracle.com>, <rostedt@goodmis.org>,
        <mingo@redhat.com>, <jgg@ziepe.ca>, <peterz@infradead.org>,
        <mgorman@suse.de>, <willy@infradead.org>, <rientjes@google.com>
References: <20201202052330.474592-1-pasha.tatashin@soleen.com>
 <20201202052330.474592-5-pasha.tatashin@soleen.com>
From:   John Hubbard <jhubbard@nvidia.com>
Message-ID: <eea5da76-e753-e7c8-60a4-c3e7e58649c1@nvidia.com>
Date:   Thu, 3 Dec 2020 00:04:55 -0800
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On 12/1/20 9:23 PM, Pavel Tatashin wrote:
> PF_MEMALLOC_NOCMA is used for longterm pinning and has an effect of
> clearing _GFP_MOVABLE or prohibiting allocations from ZONE_MOVABLE.
> 
> We will prohibit allocating any pages that are getting
> longterm pinned from ZONE_MOVABLE, and we would want to unify and re-use
> this flag. So, rename it to generic PF_MEMALLOC_NOMOVABLE.
> Also re-name:
> memalloc_nocma_save()/memalloc_nocma_restore
> to
> memalloc_nomovable_save()/memalloc_nomovable_restore()
> and make the new functions common.
> 
> Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>

Looks accurate, and grep didn't find any lingering rename candidates
after this series is applied. And it's a good rename.


Reviewed-by: John Hubbard <jhubbard@nvidia.com>


thanks,
-- 
John Hubbard
NVIDIA

> ---
>   include/linux/sched.h    |  2 +-
>   include/linux/sched/mm.h | 21 +++++----------------
>   mm/gup.c                 |  4 ++--
>   mm/hugetlb.c             |  4 ++--
>   mm/page_alloc.c          |  4 ++--
>   5 files changed, 12 insertions(+), 23 deletions(-)
> 
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 76cd21fa5501..f1bf05f5f5fa 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1548,7 +1548,7 @@ extern struct pid *cad_pid;
>   #define PF_SWAPWRITE		0x00800000	/* Allowed to write to swap */
>   #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
>   #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
> -#define PF_MEMALLOC_NOCMA	0x10000000	/* All allocation request will have _GFP_MOVABLE cleared */
> +#define PF_MEMALLOC_NOMOVABLE	0x10000000	/* All allocation request will have _GFP_MOVABLE cleared */
>   #define PF_FREEZER_SKIP		0x40000000	/* Freezer should not count it as freezable */
>   #define PF_SUSPEND_TASK		0x80000000      /* This thread called freeze_processes() and should not be frozen */
>   
> diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
> index d5ece7a9a403..5bb9a6b69479 100644
> --- a/include/linux/sched/mm.h
> +++ b/include/linux/sched/mm.h
> @@ -254,29 +254,18 @@ static inline void memalloc_noreclaim_restore(unsigned int flags)
>   	current->flags = (current->flags & ~PF_MEMALLOC) | flags;
>   }
>   
> -#ifdef CONFIG_CMA
> -static inline unsigned int memalloc_nocma_save(void)
> +static inline unsigned int memalloc_nomovable_save(void)
>   {
> -	unsigned int flags = current->flags & PF_MEMALLOC_NOCMA;
> +	unsigned int flags = current->flags & PF_MEMALLOC_NOMOVABLE;
>   
> -	current->flags |= PF_MEMALLOC_NOCMA;
> +	current->flags |= PF_MEMALLOC_NOMOVABLE;
>   	return flags;
>   }
>   
> -static inline void memalloc_nocma_restore(unsigned int flags)
> +static inline void memalloc_nomovable_restore(unsigned int flags)
>   {
> -	current->flags = (current->flags & ~PF_MEMALLOC_NOCMA) | flags;
> +	current->flags = (current->flags & ~PF_MEMALLOC_NOMOVABLE) | flags;
>   }
> -#else
> -static inline unsigned int memalloc_nocma_save(void)
> -{
> -	return 0;
> -}
> -
> -static inline void memalloc_nocma_restore(unsigned int flags)
> -{
> -}
> -#endif
>   
>   #ifdef CONFIG_MEMCG
>   DECLARE_PER_CPU(struct mem_cgroup *, int_active_memcg);
> diff --git a/mm/gup.c b/mm/gup.c
> index 0e2de888a8b0..724d8a65e1df 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -1726,7 +1726,7 @@ static long __gup_longterm_locked(struct mm_struct *mm,
>   			if (!vmas_tmp)
>   				return -ENOMEM;
>   		}
> -		flags = memalloc_nocma_save();
> +		flags = memalloc_nomovable_save();
>   	}
>   
>   	rc = __get_user_pages_locked(mm, start, nr_pages, pages,
> @@ -1749,7 +1749,7 @@ static long __gup_longterm_locked(struct mm_struct *mm,
>   		rc = check_and_migrate_cma_pages(mm, start, rc, pages,
>   						 vmas_tmp, gup_flags);
>   out:
> -		memalloc_nocma_restore(flags);
> +		memalloc_nomovable_restore(flags);
>   	}
>   
>   	if (vmas_tmp != vmas)
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 37f15c3c24dc..02213c74ed6b 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1033,10 +1033,10 @@ static void enqueue_huge_page(struct hstate *h, struct page *page)
>   static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid)
>   {
>   	struct page *page;
> -	bool nocma = !!(current->flags & PF_MEMALLOC_NOCMA);
> +	bool nomovable = !!(current->flags & PF_MEMALLOC_NOMOVABLE);
>   
>   	list_for_each_entry(page, &h->hugepage_freelists[nid], lru) {
> -		if (nocma && is_migrate_cma_page(page))
> +		if (nomovable && is_migrate_cma_page(page))
>   			continue;
>   
>   		if (PageHWPoison(page))
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index eaa227a479e4..611799c72da5 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -3772,8 +3772,8 @@ static inline unsigned int current_alloc_flags(gfp_t gfp_mask,
>   #ifdef CONFIG_CMA
>   	unsigned int pflags = current->flags;
>   
> -	if (!(pflags & PF_MEMALLOC_NOCMA) &&
> -			gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE)
> +	if (!(pflags & PF_MEMALLOC_NOMOVABLE) &&
> +	    gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE)
>   		alloc_flags |= ALLOC_CMA;
>   
>   #endif
>