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Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage
From: |
Daniel P. Berrange |
Subject: |
Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage |
Date: |
Fri, 17 Oct 2014 14:26:26 +0100 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Fri, Oct 17, 2014 at 04:57:27PM +0800, Linhaifeng wrote:
>
>
> On 2014/10/17 16:33, Daniel P. Berrange wrote:
> > On Fri, Oct 17, 2014 at 04:27:17PM +0800, address@hidden wrote:
> >> From: linhaifeng <address@hidden>
> >>
> >> The VM start with share hugepage should close the hugefile fd
> >> when exit.Because the hugepage fd may be send to other process
> >> e.g vhost-user If qemu not close the fd the other process can
> >> not free the hugepage otherwise exit process,this is ugly,so
> >> qemu should close all shared fd when exit.
> >>
> >> Signed-off-by: linhaifeng <address@hidden>
> >
> > Err, all file descriptors are closed automatically when a process
> > exits. So manually calling close(fd) before exit can't have any
> > functional effect on a resource leak.
> >
> > If QEMU has sent the FD to another process, that process has a
> > completely separate copy of the FD. Closing the FD in QEMU will
> > not close the FD in the other process. You need the other process
> > to exit for the copy to be closed.
> >
> > Regards,
> > Daniel
> >
> Hi,daniel
>
> QEMU send the fd by unix domain socket.unix domain socket just install the fd
> to
> other process and inc the f_count,if qemu not close the fd the f_count is not
> dec.
> Then the other process even close the fd the hugepage would not freed whise
> the other process exit.
The kernel always closes all FDs when a process exits. So if this FD is
not being correctly closed then it is a kernel bug. There should never
be any reason for an application to do close(fd) before exiting.
Regards,
Daniel
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- [Qemu-devel] [PATCH] fix the memory leak for share hugepage, haifeng.lin, 2014/10/17
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Daniel P. Berrange, 2014/10/17
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Gonglei, 2014/10/17
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Linhaifeng, 2014/10/17
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Linhaifeng, 2014/10/17
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage,
Daniel P. Berrange <=
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Linhaifeng, 2014/10/17
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Wen Congyang, 2014/10/19
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Linhaifeng, 2014/10/20
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Wen Congyang, 2014/10/20
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Linhaifeng, 2014/10/20
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Wen Congyang, 2014/10/20
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Linhaifeng, 2014/10/20
- Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, Daniel P. Berrange, 2014/10/20
Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage, zhanghailiang, 2014/10/17