From: Minchan Kim <minchan@kernel.org>
To: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Rik van Riel <riel@redhat.com>, Hugh Dickins <hughd@google.com>,
Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [RFC 2/8] Don't allow volatile attribute on THP and KSM
Date: Fri, 4 Jan 2013 11:51:05 +0900 [thread overview]
Message-ID: <20130104025105.GB2617@blaptop> (raw)
In-Reply-To: <50E5B173.7070807@linux.vnet.ibm.com>
On Thu, Jan 03, 2013 at 08:27:31AM -0800, Dave Hansen wrote:
> On 01/02/2013 08:28 PM, Minchan Kim wrote:
> > VOLATILE imply the the pages in the range isn't working set any more
> > so it's pointless that make them to THP/KSM.
>
> One of the points of this implementation is that it be able to preserve
> memory contents when there is no pressure. If those contents happen to
> contain a THP/KSM page, and there's no pressure, it seems like the right
> thing to do is to leave that memory in place.
Indeed. I should have written more cleary,
Current implementation is following as
1. madvised-THP/KSM(1, 10) -> mvolatile(1, 10) -> fail
2. mvolatile(1, 10) -> madvised-THP/KSM(1, 10) -> fail
3. always-THP -> mvolatile -> success -> if memory pressure happens
-> split_huge_page -> discard.
I think 2,3 makes sense to me but we need to fix 1 in further patches.
>
> It might be a fair thing to do this in order to keep the implementation
> more sane at the moment. But, we should make sure there's some good
> text on that in the changelog.
Absolutely, Thanks for pointing out, Dave.
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
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> see: http://www.linux-mm.org/ .
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--
Kind regards,
Minchan Kim
--
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WARNING: multiple messages have this Message-ID (diff)
From: Minchan Kim <minchan@kernel.org>
To: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Rik van Riel <riel@redhat.com>, Hugh Dickins <hughd@google.com>,
Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: [RFC 2/8] Don't allow volatile attribute on THP and KSM
Date: Fri, 4 Jan 2013 11:51:05 +0900 [thread overview]
Message-ID: <20130104025105.GB2617@blaptop> (raw)
In-Reply-To: <50E5B173.7070807@linux.vnet.ibm.com>
On Thu, Jan 03, 2013 at 08:27:31AM -0800, Dave Hansen wrote:
> On 01/02/2013 08:28 PM, Minchan Kim wrote:
> > VOLATILE imply the the pages in the range isn't working set any more
> > so it's pointless that make them to THP/KSM.
>
> One of the points of this implementation is that it be able to preserve
> memory contents when there is no pressure. If those contents happen to
> contain a THP/KSM page, and there's no pressure, it seems like the right
> thing to do is to leave that memory in place.
Indeed. I should have written more cleary,
Current implementation is following as
1. madvised-THP/KSM(1, 10) -> mvolatile(1, 10) -> fail
2. mvolatile(1, 10) -> madvised-THP/KSM(1, 10) -> fail
3. always-THP -> mvolatile -> success -> if memory pressure happens
-> split_huge_page -> discard.
I think 2,3 makes sense to me but we need to fix 1 in further patches.
>
> It might be a fair thing to do this in order to keep the implementation
> more sane at the moment. But, we should make sure there's some good
> text on that in the changelog.
Absolutely, Thanks for pointing out, Dave.
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org. For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
--
Kind regards,
Minchan Kim
next prev parent reply other threads:[~2013-01-04 2:51 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-03 4:27 [RFC v5 0/8] Support volatile for anonymous range Minchan Kim
2013-01-03 4:27 ` Minchan Kim
2013-01-03 4:27 ` [RFC 1/8] Introduce new system call mvolatile Minchan Kim
2013-01-03 4:27 ` Minchan Kim
2013-01-03 18:35 ` Taras Glek
2013-01-03 18:35 ` Taras Glek
2013-01-04 4:25 ` Minchan Kim
2013-01-04 4:25 ` Minchan Kim
2013-01-17 1:48 ` John Stultz
2013-01-17 1:48 ` John Stultz
2013-01-18 5:30 ` Minchan Kim
2013-01-18 5:30 ` Minchan Kim
2013-01-03 4:28 ` [RFC 2/8] Don't allow volatile attribute on THP and KSM Minchan Kim
2013-01-03 4:28 ` Minchan Kim
2013-01-03 16:27 ` Dave Hansen
2013-01-03 16:27 ` Dave Hansen
2013-01-04 2:51 ` Minchan Kim [this message]
2013-01-04 2:51 ` Minchan Kim
2013-01-03 4:28 ` [RFC 3/8] bail out when the page is in VOLATILE vma Minchan Kim
2013-01-03 4:28 ` Minchan Kim
2013-01-03 4:28 ` [RFC 4/8] add page_locked parameter in free_swap_and_cache Minchan Kim
2013-01-03 4:28 ` Minchan Kim
2013-01-03 4:28 ` [RFC 5/8] Discard volatile page Minchan Kim
2013-01-03 4:28 ` Minchan Kim
2013-01-03 4:28 ` [RFC 6/8] add PGVOLATILE vmstat count Minchan Kim
2013-01-03 4:28 ` Minchan Kim
2013-01-03 4:28 ` [RFC 7/8] add volatile page discard hook to kswapd Minchan Kim
2013-01-03 4:28 ` Minchan Kim
2013-01-03 4:28 ` [RFC 8/8] extend PGVOLATILE vmstat " Minchan Kim
2013-01-03 4:28 ` Minchan Kim
2013-01-03 17:19 ` [RFC v5 0/8] Support volatile for anonymous range Sanjay Ghemawat
2013-01-03 17:19 ` Sanjay Ghemawat
2013-01-04 5:15 ` Minchan Kim
2013-01-04 5:15 ` Minchan Kim
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