From: Marcelo Tosatti <mtosatti@redhat.com>
To: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Avi Kivity <avi@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
KVM <kvm@vger.kernel.org>
Subject: Re: [PATCH v2 4/5] KVM: MMU: introduce page_fault_start and page_fault_end
Date: Tue, 18 Sep 2012 20:43:07 -0300 [thread overview]
Message-ID: <20120918234307.GA5062@amt.cnet> (raw)
In-Reply-To: <50582DA4.8060000@linux.vnet.ibm.com>
On Tue, Sep 18, 2012 at 04:15:32PM +0800, Xiao Guangrong wrote:
> On 09/15/2012 11:25 PM, Marcelo Tosatti wrote:
> > On Fri, Sep 14, 2012 at 05:59:06PM +0800, Xiao Guangrong wrote:
> >> Wrap the common operations into these two functions
> >>
> >> Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
> >
> > Why? I think people are used to
> >
> > spin_lock(lock)
> > sequence
> > spin_unlock(lock)
>
> Marcelo,
>
> There are many functions use this style that wrap the lock into the
> _start and _end functions in kernel (eg.: cgroup_pidlist_start and
> cgroup_pidlist_stop in kernel/cgroup.c).
>
> Actually, i just wanted to remove below duplicate ugly code:
>
> if (!is_error_pfn(pfn))
> kvm_release_pfn_clean(pfn);
>
> >
> > So its easy to verify whether access to data structures are protected.
> >
> > Unrelated to this patch, one opportunity i see to simplify this
> > code is:
> >
> > - error pfn / mmio pfn / invalid pfn relation
> >
> > Have the meaning of this bits unified in a single function/helper, see
> > comment to patch 1 (perhaps you can further improve).
>
> Sorry, more detail?
Should force the reader of the code to understand error pfn / mmio pfn /
invalid pfn in a single helper. That is, avoid using error pfn at all.
>
> --
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next prev parent reply other threads:[~2012-09-19 21:23 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-14 9:56 [PATCH v2 0/5] KVM: MMU: fix release pfn in mmu code Xiao Guangrong
2012-09-14 9:57 ` [PATCH v2 1/5] KVM: MMU: release noslot pfn on the fail path properly Xiao Guangrong
2012-09-15 15:13 ` Marcelo Tosatti
2012-09-18 7:46 ` Xiao Guangrong
2012-09-14 9:57 ` [PATCH v2 2/5] KVM: MMU: do not release pfn in mmu_set_spte Xiao Guangrong
2012-09-14 9:58 ` [PATCH v2 3/5] KVM: MMU: cleanup FNAME(page_fault) Xiao Guangrong
2012-09-20 10:54 ` Avi Kivity
2012-09-14 9:59 ` [PATCH v2 4/5] KVM: MMU: introduce page_fault_start and page_fault_end Xiao Guangrong
2012-09-15 15:25 ` Marcelo Tosatti
2012-09-18 8:15 ` Xiao Guangrong
2012-09-18 23:43 ` Marcelo Tosatti [this message]
2012-09-20 2:59 ` Xiao Guangrong
2012-09-20 10:57 ` Avi Kivity
2012-09-14 9:59 ` [PATCH v2 5/5] KVM: MMU: introduce FNAME(prefetch_gpte) Xiao Guangrong
2012-09-14 10:13 ` Xiao Guangrong
2012-09-15 15:31 ` Marcelo Tosatti
2012-09-18 8:26 ` Xiao Guangrong
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