From: Andrea Arcangeli <aarcange@redhat.com>
To: Rik van Riel <riel@redhat.com>
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
linux-mm@kvack.org, avi@redhat.com
Subject: Re: [PATCH -mm 3/6] ksm: fix ksm swapin time optimization
Date: Wed, 23 Jun 2010 19:47:18 +0200 [thread overview]
Message-ID: <20100623174718.GD16195@random.random> (raw)
In-Reply-To: <20100621163439.4e76c2f8@annuminas.surriel.com>
On Mon, Jun 21, 2010 at 04:34:39PM -0400, Rik van Riel wrote:
> From: Andrea Arcangeli <aarcange@redhat.com>
> Subject: fix ksm swapin time optimization
>
> The new anon-vma code, was suboptimal and it lead to erratic invocation of
> ksm_does_need_to_copy. That leads to host hangs or guest vnc lockup, or weird
> behavior. It's unclear why ksm_does_need_to_copy is unstable but the point is
> that when KSM is not in use, ksm_does_need_to_copy must never run or we bounce
BTW, I'm debugging why ksm_does_need_to_copy breaks things... probably
I found something already, maybe not. I'll let you know as soon as I
have a fix. In the meantime the one above is a fix needed to avoid
calling ksm_does_need_to_copy erratically even when KSM is off (which
also avoids the bug to trigger).
WARNING: multiple messages have this Message-ID (diff)
From: Andrea Arcangeli <aarcange@redhat.com>
To: Rik van Riel <riel@redhat.com>
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
linux-mm@kvack.org, avi@redhat.com
Subject: Re: [PATCH -mm 3/6] ksm: fix ksm swapin time optimization
Date: Wed, 23 Jun 2010 19:47:18 +0200 [thread overview]
Message-ID: <20100623174718.GD16195@random.random> (raw)
In-Reply-To: <20100621163439.4e76c2f8@annuminas.surriel.com>
On Mon, Jun 21, 2010 at 04:34:39PM -0400, Rik van Riel wrote:
> From: Andrea Arcangeli <aarcange@redhat.com>
> Subject: fix ksm swapin time optimization
>
> The new anon-vma code, was suboptimal and it lead to erratic invocation of
> ksm_does_need_to_copy. That leads to host hangs or guest vnc lockup, or weird
> behavior. It's unclear why ksm_does_need_to_copy is unstable but the point is
> that when KSM is not in use, ksm_does_need_to_copy must never run or we bounce
BTW, I'm debugging why ksm_does_need_to_copy breaks things... probably
I found something already, maybe not. I'll let you know as soon as I
have a fix. In the meantime the one above is a fix needed to avoid
calling ksm_does_need_to_copy erratically even when KSM is off (which
also avoids the bug to trigger).
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next prev parent reply other threads:[~2010-06-23 17:47 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-21 20:31 [PATCH 0/6] further anon_vma fixes & optimizations Rik van Riel
2010-06-21 20:31 ` Rik van Riel
2010-06-21 20:33 ` [PATCH -mm 1/6] mmap: remove unnecessary lock from __vma_link Rik van Riel
2010-06-21 20:33 ` Rik van Riel
2010-06-21 20:33 ` [PATCH -mm 2/6] rmap: always add new vmas at the end Rik van Riel
2010-06-21 20:33 ` Rik van Riel
2010-06-22 21:08 ` Andrew Morton
2010-06-22 21:08 ` Andrew Morton
2010-06-22 21:10 ` Andrea Arcangeli
2010-06-22 21:10 ` Andrea Arcangeli
2010-06-21 20:34 ` [PATCH -mm 3/6] ksm: fix ksm swapin time optimization Rik van Riel
2010-06-21 20:34 ` Rik van Riel
2010-06-23 17:47 ` Andrea Arcangeli [this message]
2010-06-23 17:47 ` Andrea Arcangeli
2010-06-21 20:35 ` [PATCH -mm 4/6] always use anon_vma root pointer Rik van Riel
2010-06-21 20:35 ` Rik van Riel
2010-06-21 20:38 ` [PATCH -mm 5/6] resurrect page_address_in_vma anon_vma check Rik van Riel
2010-06-21 20:38 ` Rik van Riel
2010-06-21 20:39 ` [PATCH -mm 6/6] add anon_vma bug checks Rik van Riel
2010-06-21 20:39 ` Rik van Riel
2010-06-21 21:48 ` [PATCH 0/6] further anon_vma fixes & optimizations Andrea Arcangeli
2010-06-21 21:48 ` Andrea Arcangeli
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