From: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
To: kvm-ia64@vger.kernel.org
Subject: Re: [RFC][PATCH RFC 10/12] KVM: move dirty bitmaps to user space
Date: Thu, 13 May 2010 11:05:00 +0000 [thread overview]
Message-ID: <4BEBDCDC.4030702@oss.ntt.co.jp> (raw)
In-Reply-To: <20100504220702.f8ba6ccc.takuya.yoshikawa@gmail.com>
>>
>> mark_page_dirty is called with the mmu_lock spinlock held in set_spte.
>> Must find a way to move it outside of the spinlock section.
>>
>
> Oh, it's a serious problem. I have to consider it.
Avi, Marcelo,
Sorry but I have to say that mmu_lock spin_lock problem was completely out of
my mind. Although I looked through the code, it seems not easy to move the
set_bit_user to outside of spinlock section without breaking the semantics of
its protection.
So this may take some time to solve.
But personally, I want to do something for x86's "vmallc() every time" problem
even though moving dirty bitmaps to user space cannot be achieved soon.
In that sense, do you mind if we do double buffering without moving dirty bitmaps to
user space?
I know that the resource for vmalloc() is precious for x86 but even now, at the timing
of get_dirty_log, we use the same amount of memory as double buffering.
Thanks,
Takuya
prev parent reply other threads:[~2010-05-13 11:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-04 13:07 [RFC][PATCH RFC 10/12] KVM: move dirty bitmaps to user space Takuya Yoshikawa
2010-05-11 3:28 ` Marcelo Tosatti
2010-05-12 6:27 ` Takuya Yoshikawa
2010-05-13 11:05 ` Takuya Yoshikawa [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4BEBDCDC.4030702@oss.ntt.co.jp \
--to=yoshikawa.takuya@oss.ntt.co.jp \
--cc=kvm-ia64@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).