Re: [PATCH v2] vmscan: return NODE_RECLAIM_NOSCAN in node_reclaim() when CONFIG_NUMA is n
From: Wei Yang
Date: Tue Nov 13 2018 - 08:18:25 EST
On Tue, Nov 13, 2018 at 01:56:11PM +0100, Michal Hocko wrote:
>On Tue 13-11-18 16:04:36, Wei Yang wrote:
>> Commit fa5e084e43eb ("vmscan: do not unconditionally treat zones that
>> fail zone_reclaim() as full") changed the return value of node_reclaim().
>> The original return value 0 means NODE_RECLAIM_SOME after this commit.
>>
>> While the return value of node_reclaim() when CONFIG_NUMA is n is not
>> changed. This will leads to call zone_watermark_ok() again.
>>
>> This patch fix the return value by adjusting to NODE_RECLAIM_NOSCAN. Since
>> node_reclaim() is only called in page_alloc.c, move it to mm/internal.h.
>
>The issue should be cosmetic but the code consistency is definitely an
>improvement. Moving this from swap.h makes a lot of sense as well.
>
>> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
>
>Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Thanks.
>
>> ---
>> v2: move node_reclaim() to mm/internal.h
>> ---
>> include/linux/swap.h | 6 ------
>> mm/internal.h | 10 ++++++++++
>> 2 files changed, 10 insertions(+), 6 deletions(-)
>>
>> diff --git a/include/linux/swap.h b/include/linux/swap.h
>> index d8a07a4f171d..065988c27373 100644
>> --- a/include/linux/swap.h
>> +++ b/include/linux/swap.h
>> @@ -358,14 +358,8 @@ extern unsigned long vm_total_pages;
>> extern int node_reclaim_mode;
>> extern int sysctl_min_unmapped_ratio;
>> extern int sysctl_min_slab_ratio;
>> -extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
>> #else
>> #define node_reclaim_mode 0
>> -static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
>> - unsigned int order)
>> -{
>> - return 0;
>> -}
>> #endif
>>
>> extern int page_evictable(struct page *page);
>> diff --git a/mm/internal.h b/mm/internal.h
>> index 291eb2b6d1d8..6a57811ae47d 100644
>> --- a/mm/internal.h
>> +++ b/mm/internal.h
>> @@ -444,6 +444,16 @@ static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
>> #define NODE_RECLAIM_SOME 0
>> #define NODE_RECLAIM_SUCCESS 1
>>
>> +#ifdef CONFIG_NUMA
>> +extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
>> +#else
>> +static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
>> + unsigned int order)
>> +{
>> + return NODE_RECLAIM_NOSCAN;
>> +}
>> +#endif
>> +
>> extern int hwpoison_filter(struct page *p);
>>
>> extern u32 hwpoison_filter_dev_major;
>> --
>> 2.15.1
>
>--
>Michal Hocko
>SUSE Labs
--
Wei Yang
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