From: Dave Hansen <dave@sr71.net>
To: Minchan Kim <minchan@kernel.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, mgorman@suse.de,
tim.c.chen@linux.intel.com
Subject: Re: [v5][PATCH 5/6] mm: vmscan: batch shrink_page_list() locking operations
Date: Tue, 04 Jun 2013 08:29:18 -0700 [thread overview]
Message-ID: <51AE07CE.9040304@sr71.net> (raw)
In-Reply-To: <20130604060224.GE14719@blaptop>
On 06/03/2013 11:02 PM, Minchan Kim wrote:
>> > Why do we need new lru list instead of using @free_pages?
> I got your point that @free_pages could have freed page by
> put_page_testzero of shrink_page_list and they don't have
> valid mapping so __remove_mapping_batch's mapping_release_page
> would access NULL pointer.
>
> I think it would be better to mention it in comment. :(
> Otherwise, I suggest we can declare another new LIST_HEAD to
> accumulate pages freed by put_page_testzero in shrink_page_list
> so __remove_mapping_batch don't have to declare temporal LRU list
> and can remove unnecessary list_move operation.
If I respin them again, I'll add a comment.
I guess we could splice the whole list over at once instead of moving
the pages individually. But, what are we trying to optimize here?
Saving a list_head worth of space on the stack?
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WARNING: multiple messages have this Message-ID (diff)
From: Dave Hansen <dave@sr71.net>
To: Minchan Kim <minchan@kernel.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, mgorman@suse.de,
tim.c.chen@linux.intel.com
Subject: Re: [v5][PATCH 5/6] mm: vmscan: batch shrink_page_list() locking operations
Date: Tue, 04 Jun 2013 08:29:18 -0700 [thread overview]
Message-ID: <51AE07CE.9040304@sr71.net> (raw)
In-Reply-To: <20130604060224.GE14719@blaptop>
On 06/03/2013 11:02 PM, Minchan Kim wrote:
>> > Why do we need new lru list instead of using @free_pages?
> I got your point that @free_pages could have freed page by
> put_page_testzero of shrink_page_list and they don't have
> valid mapping so __remove_mapping_batch's mapping_release_page
> would access NULL pointer.
>
> I think it would be better to mention it in comment. :(
> Otherwise, I suggest we can declare another new LIST_HEAD to
> accumulate pages freed by put_page_testzero in shrink_page_list
> so __remove_mapping_batch don't have to declare temporal LRU list
> and can remove unnecessary list_move operation.
If I respin them again, I'll add a comment.
I guess we could splice the whole list over at once instead of moving
the pages individually. But, what are we trying to optimize here?
Saving a list_head worth of space on the stack?
next prev parent reply other threads:[~2013-06-04 15:29 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-03 20:02 [v5][PATCH 0/6] mm: vmscan: Batch page reclamation under shink_page_list Dave Hansen
2013-06-03 20:02 ` Dave Hansen
2013-06-03 20:02 ` [v5][PATCH 1/6] mm: swap: defer clearing of page_private() for swap cache pages Dave Hansen
2013-06-03 20:02 ` Dave Hansen
2013-07-14 23:47 ` Wanpeng Li
2013-07-14 23:47 ` Wanpeng Li
2013-06-03 20:02 ` [v5][PATCH 2/6] mm: swap: make 'struct page' and swp_entry_t variants of swapcache_free() Dave Hansen
2013-06-03 20:02 ` Dave Hansen
2013-07-14 23:48 ` Wanpeng Li
2013-07-14 23:48 ` Wanpeng Li
2013-06-03 20:02 ` [v5][PATCH 3/6] mm: vmscan: break up __remove_mapping() Dave Hansen
2013-06-03 20:02 ` Dave Hansen
2013-07-14 23:49 ` Wanpeng Li
2013-07-14 23:49 ` Wanpeng Li
2013-06-03 20:02 ` [v5][PATCH 4/6] mm: vmscan: break out mapping "freepage" code Dave Hansen
2013-06-03 20:02 ` Dave Hansen
2013-07-14 23:49 ` Wanpeng Li
2013-07-14 23:49 ` Wanpeng Li
2013-06-03 20:02 ` [v5][PATCH 5/6] mm: vmscan: batch shrink_page_list() locking operations Dave Hansen
2013-06-03 20:02 ` Dave Hansen
2013-06-04 1:17 ` Hillf Danton
2013-06-04 1:17 ` Hillf Danton
2013-06-04 5:07 ` Minchan Kim
2013-06-04 5:07 ` Minchan Kim
2013-06-04 15:22 ` Dave Hansen
2013-06-04 15:22 ` Dave Hansen
2013-06-05 7:28 ` Hillf Danton
2013-06-05 7:28 ` Hillf Danton
2013-06-05 7:57 ` Minchan Kim
2013-06-05 7:57 ` Minchan Kim
2013-06-05 14:24 ` Dave Hansen
2013-06-05 14:24 ` Dave Hansen
2013-06-04 5:01 ` Minchan Kim
2013-06-04 5:01 ` Minchan Kim
2013-06-04 6:02 ` Minchan Kim
2013-06-04 6:02 ` Minchan Kim
2013-06-04 15:29 ` Dave Hansen [this message]
2013-06-04 15:29 ` Dave Hansen
2013-06-04 23:32 ` Minchan Kim
2013-06-04 23:32 ` Minchan Kim
2013-06-04 6:10 ` Dave Hansen
2013-06-04 6:10 ` Dave Hansen
2013-06-04 6:59 ` Minchan Kim
2013-06-04 6:59 ` Minchan Kim
2013-07-14 23:50 ` Wanpeng Li
2013-07-14 23:50 ` Wanpeng Li
2013-06-03 20:02 ` [v5][PATCH 6/6] mm: vmscan: drain batch list during long operations Dave Hansen
2013-06-03 20:02 ` Dave Hansen
2013-06-04 6:05 ` Minchan Kim
2013-06-04 6:05 ` Minchan Kim
2013-06-04 15:24 ` Dave Hansen
2013-06-04 15:24 ` Dave Hansen
2013-06-04 23:23 ` Minchan Kim
2013-06-04 23:23 ` Minchan Kim
2013-06-04 23:31 ` Dave Hansen
2013-06-04 23:31 ` Dave Hansen
2013-06-04 23:36 ` Minchan Kim
2013-06-04 23:36 ` Minchan Kim
2013-06-04 23:37 ` Minchan Kim
2013-06-04 23:37 ` Minchan Kim
2013-07-14 23:51 ` Wanpeng Li
2013-07-14 23:51 ` Wanpeng Li
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