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Subject: Re: [PATCH RFC 1/4] mm/page_alloc: convert "report" flag of
 __free_one_page() to a proper flag
To:     Wei Yang <richard.weiyang@linux.alibaba.com>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        linux-hyperv@vger.kernel.org, xen-devel@lists.xenproject.org,
        linux-acpi@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexander Duyck <alexander.h.duyck@linux.intel.com>,
        Mel Gorman <mgorman@techsingularity.net>,
        Michal Hocko <mhocko@kernel.org>,
        Dave Hansen <dave.hansen@intel.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Oscar Salvador <osalvador@suse.de>,
        Mike Rapoport <rppt@kernel.org>
References: <20200916183411.64756-1-david@redhat.com>
 <20200916183411.64756-2-david@redhat.com>
 <20200918015325.GA54754@L-31X9LVDL-1304.local>
From:   David Hildenbrand <david@redhat.com>
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Message-ID: <c49cf22c-7b34-a7d2-c7d2-ac322150e4a6@redhat.com>
Date:   Fri, 18 Sep 2020 09:23:16 +0200
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On 18.09.20 03:53, Wei Yang wrote:
> On Wed, Sep 16, 2020 at 08:34:08PM +0200, David Hildenbrand wrote:
>> Let's prepare for additional flags and avoid long parameter lists of bools.
>> Follow-up patches will also make use of the flags in __free_pages_ok(),
>> however, I wasn't able to come up with a better name for the type - should
>> be good enough for internal purposes.
>>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
>> Cc: Mel Gorman <mgorman@techsingularity.net>
>> Cc: Michal Hocko <mhocko@kernel.org>
>> Cc: Dave Hansen <dave.hansen@intel.com>
>> Cc: Vlastimil Babka <vbabka@suse.cz>
>> Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
>> Cc: Oscar Salvador <osalvador@suse.de>
>> Cc: Mike Rapoport <rppt@kernel.org>
>> Signed-off-by: David Hildenbrand <david@redhat.com>
>> ---
>> mm/page_alloc.c | 28 ++++++++++++++++++++--------
>> 1 file changed, 20 insertions(+), 8 deletions(-)
>>
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index 6b699d273d6e..91cefb8157dd 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -77,6 +77,18 @@
>> #include "shuffle.h"
>> #include "page_reporting.h"
>>
>> +/* Free One Page flags: for internal, non-pcp variants of free_pages(). */
>> +typedef int __bitwise fop_t;
>> +
>> +/* No special request */
>> +#define FOP_NONE		((__force fop_t)0)
>> +
>> +/*
>> + * Skip free page reporting notification after buddy merging (will *not* mark
> 
> __free_one_page() may not merge buddy when its buddy is not available.
> 
> Would this comment be a little confusing?
> 

I rather meant the process than if it's actually happening.

"Skip free page reporting notification for the (possibly merged) page."

Thanks!

-- 
Thanks,

David / dhildenb