<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Aug 10, 2015 at 12:58 PM, Pavel Emelyanov <span dir="ltr"><<a href="mailto:xemul@parallels.com" target="_blank">xemul@parallels.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On 08/10/2015 07:43 PM, Hui Kang wrote:<br>
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> On Mon, Aug 10, 2015 at 12:35 PM, Pavel Emelyanov <<a href="mailto:xemul@parallels.com">xemul@parallels.com</a> <mailto:<a href="mailto:xemul@parallels.com">xemul@parallels.com</a>>> wrote:<br>
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> On 08/10/2015 06:00 PM, Hui Kang wrote:<br>
> > The process to be restored may not have certain cgroup dir, e.g<br>
> > cpu/[PID]/cpu.shares. Currently restoring will fail in closing<br>
> > the file. If this is the case, the fileno is -1 and we can ignore<br>
> > this and let the restore proceed.<br>
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> If the file is missing then the fopen() itself should return -1.<br>
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> Hi, Pavel<br>
> The file is not missing in the destination, e.g., cpu/cpu.shares. The open and write are<br>
> successful, e.g., fileno returning 5. Only fclose return error. But if you check fileno(f)<br>
> after fclose, it returns -1. That's why I added the additional check for this.<br>
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</span>I see, but this means, that we have actually failed to restore the cgroup property.<br>
I would find out why write() fails, that's the real bug we have.<br></blockquote><div><br></div><div>I found that it always fails to write into the top level of cgroups, e.g., <br></div><div>echo "1024" > /sys/fs/cgroup/cpu/cpu.share.<br><br></div><div>However, when using manage-cgroup=full to restore a process, criu will try to propagate these files, so the write will fail. The reason fprintf returns success is because the data actually has not been flushed to the file (although cgroup is a virtual file system). So I submitted another patch to fix this (see <a href="http://lists.openvz.org/pipermail/criu/2015-August/021743.html">http://lists.openvz.org/pipermail/criu/2015-August/021743.html</a>)<br><br></div><div>- Hui<br><br><br><br></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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-- Pavel<br>
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