Re: [PATCH] mm: ALLOC_HIGHATOMIC flag allocation issue

[zhiguojiang]

Thanks, I have updated the related modifications according to  your 
suggestions in patch v2.

在 2023/11/21 1:29, Matthew Wilcox 写道:
> On Mon, Nov 20, 2023 at 10:35:36AM +0800, Zhiguo Jiang wrote:
> > +			/*
> > +			 * If pcplist is empty and alloc_flags is with ALLOC_HIGHATOMIC,
> > +			 * it should alloc from buddy highatomic migrate freelist firstly
> > +			 * to ensure quick and successful allocation.
> Assuming that all the serious question shave been dealt with, let's
> fix the less important problems ...
>
> 			 * If pcplist is empty and alloc_flags contains
> 			 * ALLOC_HIGHATOMIC, alloc from buddy highatomic
> 			 * freelist first.
>
> > @@ -2918,7 +2927,7 @@ static inline
> >   struct page *rmqueue(struct zone *preferred_zone,
> >   			struct zone *zone, unsigned int order,
> >   			gfp_t gfp_flags, unsigned int alloc_flags,
> > -			int migratetype)
> > +			int migratetype, bool *highatomc_allocation)
> bool *highatomic
>
> > +	/*
> > +	 * The high-order atomic allocation pageblock reserved conditions:
> > +	 *
> > +	 * If the high-order atomic allocation page is alloced from pcplist,
> > +	 * the highatomic pageblock does not need to be reserved, which can
> > +	 * void to migrate an increasing number of pages into buddy
> 	 * avoid migrating an increasing number of pages into buddy
>
> > +	 * MIGRATE_HIGHATOMIC freelist and lead to an increasing risk of
> "increased"
>
> > +	 * allocation failure on other buddy migrate freelists.
> > +	 *
> > +	 * If the high-order atomic allocation page is alloced from buddy
> "allocated"
>
> > @@ -3208,6 +3234,7 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
> >   	struct pglist_data *last_pgdat = NULL;
> >   	bool last_pgdat_dirty_ok = false;
> >   	bool no_fallback;
> > +	bool highatomc_allocation = false;
> Again, just call this 'highatomic'.