Re: [PATCH 3/4][mmotm] memcg: fix gfp_mask of callers of charge

[Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>]

On Tue, 28 Oct 2008 19:14:49 +0900, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> fix misuse of gfp_kernel.
> 
> Now, most of callers of mem_cgroup_charge_xxx functions uses GFP_KERNEL.
> 
> I think that this is from the fact that page_cgroup *was* dynamically allocated.
> 
> But now, we allocate all page_cgroup at boot. And mem_cgroup_try_to_free_pages()
> reclaim memory from GFP_HIGHUSER_MOVABLE + specified GFP_RECLAIM_MASK.
>   * This is because we just want to reduce memory usage.
>     "Where we should reclaim from ?" is not a problem in memcg.
> 
> This patch modifies gfp masks to be GFP_HIGUSER_MOVABLE if possible.
> Note: This patch is not for fixing behavior but for showing sane information
>       in source code.
> 
> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> 
> 
>  mm/memcontrol.c |    8 +++++---
>  mm/memory.c     |    9 +++++----
>  mm/shmem.c      |    6 +++---
>  mm/swapfile.c   |    2 +-
>  4 files changed, 14 insertions(+), 11 deletions(-)
> 
> Index: mmotm-2.6.28rc2+/mm/memcontrol.c
> ===================================================================
> --- mmotm-2.6.28rc2+.orig/mm/memcontrol.c
> +++ mmotm-2.6.28rc2+/mm/memcontrol.c
> @@ -808,8 +808,9 @@ int mem_cgroup_prepare_migration(struct 
>  	}
>  	unlock_page_cgroup(pc);
>  	if (mem) {
> -		ret = mem_cgroup_charge_common(newpage, NULL, GFP_KERNEL,
> -			ctype, mem);
> +		ret = mem_cgroup_charge_common(newpage, NULL,
> +					GFP_HIGHUSER_MOVABLE,
> +					ctype, mem);
>  		css_put(&mem->css);
>  	}
>  	return ret;
> @@ -888,7 +889,8 @@ int mem_cgroup_resize_limit(struct mem_c
>  			ret = -EBUSY;
>  			break;
>  		}
> -		progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL);
> +		progress = try_to_free_mem_cgroup_pages(memcg,
> +				GFP_HIGHUSER_MOVABLE);
>  		if (!progress)
>  			retry_count--;
>  	}
> Index: mmotm-2.6.28rc2+/mm/memory.c
> ===================================================================
> --- mmotm-2.6.28rc2+.orig/mm/memory.c
> +++ mmotm-2.6.28rc2+/mm/memory.c
> @@ -1889,7 +1889,7 @@ gotten:
>  	cow_user_page(new_page, old_page, address, vma);
>  	__SetPageUptodate(new_page);
>  
> -	if (mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))
> +	if (mem_cgroup_newpage_charge(new_page, mm, GFP_HIGHUSER_MOVABLE))
>  		goto oom_free_new;
>  
>  	/*
> @@ -2324,7 +2324,7 @@ static int do_swap_page(struct mm_struct
>  	lock_page(page);
>  	delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
>  
> -	if (mem_cgroup_try_charge(mm, GFP_KERNEL, &ptr) == -ENOMEM) {
> +	if (mem_cgroup_try_charge(mm, GFP_HIGHUSER_MOVABLE, &ptr) == -ENOMEM) {
>  		ret = VM_FAULT_OOM;
>  		unlock_page(page);
>  		goto out;
> @@ -2405,7 +2405,7 @@ static int do_anonymous_page(struct mm_s
>  		goto oom;
>  	__SetPageUptodate(page);
>  
> -	if (mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))
> +	if (mem_cgroup_newpage_charge(page, mm, GFP_HIGHUSER_MOVABLE))
>  		goto oom_free_page;
>  
>  	entry = mk_pte(page, vma->vm_page_prot);
> @@ -2498,7 +2498,8 @@ static int __do_fault(struct mm_struct *
>  				ret = VM_FAULT_OOM;
>  				goto out;
>  			}
> -			if (mem_cgroup_newpage_charge(page, mm, GFP_KERNEL)) {
> +			if (mem_cgroup_newpage_charge(page,
> +						mm, GFP_HIGHUSER_MOVABLE)) {
>  				ret = VM_FAULT_OOM;
>  				page_cache_release(page);
>  				goto out;
> Index: mmotm-2.6.28rc2+/mm/swapfile.c
> ===================================================================
> --- mmotm-2.6.28rc2+.orig/mm/swapfile.c
> +++ mmotm-2.6.28rc2+/mm/swapfile.c
> @@ -535,7 +535,7 @@ static int unuse_pte(struct vm_area_stru
>  	pte_t *pte;
>  	int ret = 1;
>  
> -	if (mem_cgroup_try_charge(vma->vm_mm, GFP_KERNEL, &ptr))
> +	if (mem_cgroup_try_charge(vma->vm_mm, GFP_HIGHUSER_MOVABLE, &ptr))
>  		ret = -ENOMEM;
>  
>  	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
> Index: mmotm-2.6.28rc2+/mm/shmem.c
> ===================================================================
> --- mmotm-2.6.28rc2+.orig/mm/shmem.c
> +++ mmotm-2.6.28rc2+/mm/shmem.c
> @@ -920,8 +920,8 @@ found:
>  	error = 1;
>  	if (!inode)
>  		goto out;
> -	/* Precharge page using GFP_KERNEL while we can wait */
> -	error = mem_cgroup_cache_charge(page, current->mm, GFP_KERNEL);
> +	/* Charge page using GFP_HIGHUSER_MOVABLE while we can wait */
> +	error = mem_cgroup_cache_charge(page, current->mm, GFP_HIGHUSER_MOVABLE);
This line exceeds 80 characters.

Looks good to me except for that.

	Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>


>  	if (error)
>  		goto out;
>  	error = radix_tree_preload(GFP_KERNEL);
> @@ -1371,7 +1371,7 @@ repeat:
>  
>  			/* Precharge page while we can wait, compensate after */
>  			error = mem_cgroup_cache_charge(filepage, current->mm,
> -							gfp & ~__GFP_HIGHMEM);
> +					GFP_HIGHUSER_MOVABLE);
>  			if (error) {
>  				page_cache_release(filepage);
>  				shmem_unacct_blocks(info->flags, 1);
>