From: Vlastimil Babka <vbabka@suse.cz>
To: David Hildenbrand <david@redhat.com>,
yanfei.xu@windriver.com, akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/compaction: Remove some useless code in compact_zone()
Date: Fri, 16 Oct 2020 17:05:52 +0200 [thread overview]
Message-ID: <ec5c9395-23f9-2b6a-0709-887751ff2d56@suse.cz> (raw)
In-Reply-To: <dc40599d-e964-3a53-f3e7-94c03d3a162c@redhat.com>
On 10/14/20 2:28 PM, David Hildenbrand wrote:
> On 14.10.20 09:23, yanfei.xu@windriver.com wrote:
>> From: Yanfei Xu <yanfei.xu@windriver.com>
>>
>> start_pfn has been declared at the begin of compact_zone(), it's
>> no need to declare it again. And remove an useless semicolon.
>>
>> Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
>> ---
>> mm/compaction.c | 3 +--
>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/mm/compaction.c b/mm/compaction.c
>> index 176dcded298e..5e69c1f94d96 100644
>> --- a/mm/compaction.c
>> +++ b/mm/compaction.c
>> @@ -2272,7 +2272,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
>>
>> while ((ret = compact_finished(cc)) == COMPACT_CONTINUE) {
>> int err;
>> - unsigned long start_pfn = cc->migrate_pfn;
>> + start_pfn = cc->migrate_pfn;
>
> There is a user in
>
> trace_mm_compaction_end(start_pfn, cc->migrate_pfn, cc->free_pfn,
> end_pfn, sync, ret);
>
> we would now trace a different value, no?
Agreed. We should rather rename the while-local one to avoid confusion.
Something like "iteration_start_pfn" ?
>>
>> /*
>> * Avoid multiple rescans which can happen if a page cannot be
>> @@ -2309,7 +2309,6 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
>> case ISOLATE_SUCCESS:
>> update_cached = false;
>> last_migrated_pfn = start_pfn;
>> - ;
>
> Huh, how does something like that happen :)
Looks like "case ISOLATE_SUCCESS:" used to be an empty implementation, then
statements got added, but semicolon not removed.
next prev parent reply other threads:[~2020-10-16 15:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-14 7:23 [PATCH] mm/compaction: Remove some useless code in compact_zone() yanfei.xu
2020-10-14 12:28 ` David Hildenbrand
2020-10-16 15:05 ` Vlastimil Babka [this message]
2020-10-19 7:32 ` Xu, Yanfei
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