Re: [PATCH] block,blkcg: use __GFP_NOWARN for best-effort allocations in blkcg

From	Vlastimil Babka <vbabka@suse.cz>
Newsgroups	linux.kernel
Subject	Re: [PATCH] block,blkcg: use __GFP_NOWARN for best-effort allocations in blkcg
Date	2016-11-29 18:00 +0100
Message-ID	<sITV8-2B3-11@gated-at.bofh.it> (permalink)
References	(6 earlier) <sGrzX-4Ma-9@gated-at.bofh.it> <sGBzk-2Bt-21@gated-at.bofh.it> <sIxKW-4YT-29@gated-at.bofh.it> <sIL1v-5fn-11@gated-at.bofh.it> <sITBL-2rZ-17@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 11/29/2016 05:38 PM, Tejun Heo wrote:
> On Tue, Nov 29, 2016 at 08:25:07AM +0100, Michal Hocko wrote:
>> --- a/include/linux/gfp.h
>> +++ b/include/linux/gfp.h
>> @@ -246,7 +246,7 @@ struct vm_area_struct;
>>  #define GFP_ATOMIC	(__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
>>  #define GFP_KERNEL	(__GFP_RECLAIM | __GFP_IO | __GFP_FS)
>>  #define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)
>> -#define GFP_NOWAIT	(__GFP_KSWAPD_RECLAIM)
>> +#define GFP_NOWAIT	(__GFP_KSWAPD_RECLAIM|__GFP_NOWARN)
>>  #define GFP_NOIO	(__GFP_RECLAIM)
>>  #define GFP_NOFS	(__GFP_RECLAIM | __GFP_IO)
>>  #define GFP_TEMPORARY	(__GFP_RECLAIM | __GFP_IO | __GFP_FS | \
>>
>> this will not catch users who are doing gfp & ~__GFP_DIRECT_RECLAIM but
>> I would rather not make warn_alloc() even more cluttered with checks.
>
> Yeah, FWIW, looks good to me.

Me too. Just don't forget to update the comment describing GFP_NOWAIT and check 
the existing users if duplicite __GFP_NOWARN can be removed, and if they really 
want to be doing GFP_NOWAIT and not GFP_ATOMIC.

Also dunno what about Tejun's eariler patch.

Thread

Re: [PATCH] block,blkcg: use __GFP_NOWARN for best-effort  allocations in blkcg Tejun Heo <tj@kernel.org> - 2016-11-28 18:20 +0100
  Re: [PATCH] block,blkcg: use __GFP_NOWARN for best-effort  allocations in blkcg Michal Hocko <mhocko@kernel.org> - 2016-11-29 08:30 +0100
    Re: [PATCH] block,blkcg: use __GFP_NOWARN for best-effort  allocations in blkcg Tejun Heo <tj@kernel.org> - 2016-11-29 17:40 +0100
      Re: [PATCH] block,blkcg: use __GFP_NOWARN for best-effort allocations  in blkcg Vlastimil Babka <vbabka@suse.cz> - 2016-11-29 18:00 +0100
        Re: [PATCH] block,blkcg: use __GFP_NOWARN for best-effort allocations  in blkcg Linus Torvalds <torvalds@linux-foundation.org> - 2016-11-29 18:20 +0100
          Re: [PATCH] block,blkcg: use __GFP_NOWARN for best-effort  allocations in blkcg Michal Hocko <mhocko@kernel.org> - 2016-11-29 18:30 +0100
            Re: [PATCH] block,blkcg: use __GFP_NOWARN for best-effort allocations  in blkcg Linus Torvalds <torvalds@linux-foundation.org> - 2016-11-29 18:50 +0100
        Re: [PATCH] block,blkcg: use __GFP_NOWARN for best-effort  allocations in blkcg Michal Hocko <mhocko@kernel.org> - 2016-11-29 18:20 +0100

csiph-web