From: Olaf Hering <olaf@aepfle.de>
To: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Cc: andres@gridcentric.ca, xen-devel@lists.xensource.com,
tim@xen.org, adin@gridcentric.ca
Subject: Re: [PATCH] x86/mm: Improve ring management for memory events. Do not lose guest events
Date: Fri, 13 Jan 2012 20:57:06 +0100 [thread overview]
Message-ID: <20120113195706.GA26566@aepfle.de> (raw)
In-Reply-To: <873a666b95bbe7e50992fb1059bc2220.squirrel@webmail.lagarcavilla.org>
On Fri, Jan 13, Andres Lagar-Cavilla wrote:
> > p2m_mem_paging_drop_page() should remain void because the caller has
> > already done its work, making it not restartable. Also it is only called
> > when a gfn is in paging state, which I'm sure can not happen without a
> > ring.
>
> Well, the rationale is that returning an error code can only help, should
> new error conditions arise. Keep in mind that the pager and the ring can
> disappear at any time, so ENOSYS can still happen.
The ring should rather not disappear at all until ->paged_pages drops to
zero. Unless the goal is a restartable pager,
XEN_DOMCTL_MEM_EVENT_OP_PAGING_DISABLE should return -EBUSY when
->pages_pages is not zero. Then the checks in drop_page and populate can
be relaxed.
> I'll refresh and add your signed-off-by to cover the portions of the work
> that originate from your end, is that ok?
I havent finish the review yet, have to check how it may work with wait
queues in gfn_to_mfn*.
Olaf
next prev parent reply other threads:[~2012-01-13 19:57 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-11 18:28 [PATCH] x86/mm: Improve ring management for memory events. Do not lose guest events Andres Lagar-Cavilla
2012-01-12 11:56 ` Tim Deegan
2012-01-12 16:05 ` Andres Lagar-Cavilla
2012-01-13 9:50 ` Olaf Hering
2012-01-13 15:14 ` Andres Lagar-Cavilla
2012-01-13 19:57 ` Olaf Hering [this message]
2012-01-13 20:05 ` Andres Lagar-Cavilla
2012-01-16 15:08 ` Olaf Hering
2012-01-16 16:22 ` Olaf Hering
2012-01-16 15:04 ` Olaf Hering
2012-01-16 15:08 ` Andres Lagar-Cavilla
2012-01-16 15:10 ` Olaf Hering
2012-01-16 15:22 ` Olaf Hering
-- strict thread matches above, loose matches on Subject: below --
2012-01-16 15:39 Andres Lagar-Cavilla
2012-01-16 15:41 ` Olaf Hering
2012-01-19 10:39 ` Tim Deegan
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