lkml.org 
[lkml]   [2014]   [Apr]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH -mm v2.1] mm: get rid of __GFP_KMEMCG
On 04/03/2014 01:25 AM, Greg Thelen wrote:
> On Tue, Apr 01 2014, Vladimir Davydov <vdavydov@parallels.com> wrote:
>
>> Currently to allocate a page that should be charged to kmemcg (e.g.
>> threadinfo), we pass __GFP_KMEMCG flag to the page allocator. The page
>> allocated is then to be freed by free_memcg_kmem_pages. Apart from
>> looking asymmetrical, this also requires intrusion to the general
>> allocation path. So let's introduce separate functions that will
>> alloc/free pages charged to kmemcg.
>>
>> The new functions are called alloc_kmem_pages and free_kmem_pages. They
>> should be used when the caller actually would like to use kmalloc, but
>> has to fall back to the page allocator for the allocation is large. They
>> only differ from alloc_pages and free_pages in that besides allocating
>> or freeing pages they also charge them to the kmem resource counter of
>> the current memory cgroup.
>>
>> Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
> One comment nit below, otherwise looks good to me.
>
> Acked-by: Greg Thelen <gthelen@google.com>
>
>> Cc: Johannes Weiner <hannes@cmpxchg.org>
>> Cc: Michal Hocko <mhocko@suse.cz>
>> Cc: Glauber Costa <glommer@gmail.com>
>> Cc: Christoph Lameter <cl@linux-foundation.org>
>> Cc: Pekka Enberg <penberg@kernel.org>
>> ---
>> Changes in v2.1:
>> - add missing kmalloc_order forward declaration; lacking it caused
>> compilation breakage with CONFIG_TRACING=n
>>
>> include/linux/gfp.h | 10 ++++---
>> include/linux/memcontrol.h | 2 +-
>> include/linux/slab.h | 11 +-------
>> include/linux/thread_info.h | 2 --
>> include/trace/events/gfpflags.h | 1 -
>> kernel/fork.c | 6 ++---
>> mm/page_alloc.c | 56 ++++++++++++++++++++++++---------------
>> mm/slab_common.c | 12 +++++++++
>> mm/slub.c | 6 ++---
>> 9 files changed, 61 insertions(+), 45 deletions(-)
>>
>> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
>> index 39b81dc7d01a..d382db71e300 100644
>> --- a/include/linux/gfp.h
>> +++ b/include/linux/gfp.h
>> @@ -31,7 +31,6 @@ struct vm_area_struct;
>> #define ___GFP_HARDWALL 0x20000u
>> #define ___GFP_THISNODE 0x40000u
>> #define ___GFP_RECLAIMABLE 0x80000u
>> -#define ___GFP_KMEMCG 0x100000u
>> #define ___GFP_NOTRACK 0x200000u
>> #define ___GFP_NO_KSWAPD 0x400000u
>> #define ___GFP_OTHER_NODE 0x800000u
>> @@ -91,7 +90,6 @@ struct vm_area_struct;
>>
>> #define __GFP_NO_KSWAPD ((__force gfp_t)___GFP_NO_KSWAPD)
>> #define __GFP_OTHER_NODE ((__force gfp_t)___GFP_OTHER_NODE) /* On behalf of other node */
>> -#define __GFP_KMEMCG ((__force gfp_t)___GFP_KMEMCG) /* Allocation comes from a memcg-accounted resource */
>> #define __GFP_WRITE ((__force gfp_t)___GFP_WRITE) /* Allocator intends to dirty page */
>>
>> /*
>> @@ -353,6 +351,10 @@ extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
>> #define alloc_page_vma_node(gfp_mask, vma, addr, node) \
>> alloc_pages_vma(gfp_mask, 0, vma, addr, node)
>>
>> +extern struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order);
>> +extern struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask,
>> + unsigned int order);
>> +
>> extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
>> extern unsigned long get_zeroed_page(gfp_t gfp_mask);
>>
>> @@ -372,8 +374,8 @@ extern void free_pages(unsigned long addr, unsigned int order);
>> extern void free_hot_cold_page(struct page *page, int cold);
>> extern void free_hot_cold_page_list(struct list_head *list, int cold);
>>
>> -extern void __free_memcg_kmem_pages(struct page *page, unsigned int order);
>> -extern void free_memcg_kmem_pages(unsigned long addr, unsigned int order);
>> +extern void __free_kmem_pages(struct page *page, unsigned int order);
>> +extern void free_kmem_pages(unsigned long addr, unsigned int order);
>>
>> #define __free_page(page) __free_pages((page), 0)
>> #define free_page(addr) free_pages((addr), 0)
>> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
>> index 29068dd26c3d..13acdb5259f5 100644
>> --- a/include/linux/memcontrol.h
>> +++ b/include/linux/memcontrol.h
>> @@ -543,7 +543,7 @@ memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg, int order)
>> * res_counter_charge_nofail, but we hope those allocations are rare,
>> * and won't be worth the trouble.
>> */
> Just a few lines higher in first memcg_kmem_newpage_charge() comment,
> there is a leftover reference to GFP_KMEMCG which should be removed.

Good catch, will resend.

Thank you for the review!


\
 
 \ /
  Last update: 2014-04-04 08:21    [W:0.101 / U:0.680 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site