From: shijie8 <shijie8@gmail.com>
To: Minchan Kim <minchan.kim@gmail.com>
Cc: akpm@linux-foundation.org, mel@csn.ul.ie, linux-mm@kvack.org
Subject: Re: [PATCH] mm : add check for the return value
Date: Mon, 04 Jan 2010 12:10:16 +0800 [thread overview]
Message-ID: <4B416A28.70806@gmail.com> (raw)
In-Reply-To: <20100104122138.f54b7659.minchan.kim@barrios-desktop>
> I think it's not desirable to add new branch in hot-path even though
> we could avoid that.
>
> How about this?
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 4e4b5b3..87976ad 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1244,6 +1244,9 @@ again:
> return page;
>
> failed:
>
you miss anther place where also uses "goto failed".
> + spin_lock(&zone->lock);
> + __mod_zone_page_state(zone, NR_FREE_PAGES, 1<< order);
> + spin_unlock(&zone->lock);
> local_irq_restore(flags);
> put_cpu();
> return NULL;
>
>
I also thought over your method before I sent the patch, but there
already exits a
"if (!page)" , I not sure whether my patch adds too much delay in hot-path.
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next prev parent reply other threads:[~2010-01-04 4:10 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-04 2:22 [PATCH] mm : add check for the return value Huang Shijie
2010-01-04 3:21 ` Minchan Kim
2010-01-04 4:10 ` shijie8 [this message]
2010-01-04 4:48 ` Minchan Kim
2010-01-04 5:18 ` Huang Shijie
2010-01-04 6:06 ` Minchan Kim
2010-01-08 22:59 ` Andrew Morton
2010-01-04 5:52 ` [PATCH] page allocator: fix update NR_FREE_PAGES only as necessary KOSAKI Motohiro
2010-01-04 6:03 ` Minchan Kim
2010-01-04 6:11 ` Huang Shijie
2010-01-04 6:16 ` KOSAKI Motohiro
2010-01-04 9:35 ` Huang Shijie
2010-01-05 7:24 ` KOSAKI Motohiro
2010-01-04 9:58 ` Mel Gorman
2010-01-04 17:46 ` Christoph Lameter
2010-01-05 1:08 ` KOSAKI Motohiro
2010-01-08 23:02 ` Andrew Morton
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