linux-kernel - Re: [PATCH] mm: skip the page buddy block instead of one page

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 15 Aug 2013 23:16:53 +0900
From:	Minchan Kim <minchan@...nel.org>
To:	Mel Gorman <mgorman@...e.de>
Cc:	Xishi Qiu <qiuxishi@...wei.com>,
	Andrew Morton <akpm@...ux-foundation.org>, riel@...hat.com,
	aquini@...hat.com, linux-mm@...ck.org,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] mm: skip the page buddy block instead of one page

On Thu, Aug 15, 2013 at 02:42:09PM +0100, Mel Gorman wrote:
> On Thu, Aug 15, 2013 at 10:19:35PM +0900, Minchan Kim wrote:
> > > 
> > > Why? We're looking for pages to migrate. If the page is free and at the
> > > maximum order then there is no point searching in the middle of a free
> > > page.
> > 
> > isolate_migratepages_range API works with [low_pfn, end_pfn)
> > and we can't guarantee page_order in normal compaction path
> > so I'd like to limit the skipping by end_pfn conservatively.
> > 
> 
> Fine
> 
> s/MAX_ORDER_NR_PAGES/pageblock_nr_pages/
> 
> and take the min of it and
> 
> low_pfn = min(low_pfn, end_pfn - 1)

True. That was really what I suggested to Xishi.
Only thing we need it is just number to justify for proving the benefit.

Thanks.

-- 
Kind regards,
Minchan Kim
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/