[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 3/8] migration: support todetectcompression and
From: |
Peter Xu |
Subject: |
Re: [Qemu-devel] [PATCH 3/8] migration: support todetectcompression and decompression errors |
Date: |
Wed, 28 Mar 2018 12:20:03 +0800 |
User-agent: |
Mutt/1.9.1 (2017-09-22) |
On Wed, Mar 28, 2018 at 12:08:19PM +0800, address@hidden wrote:
> >
> > On Tue, Mar 27, 2018 at 10:35:29PM +0800, Xiao Guangrong wrote:
> >
> >> > > No, we can't make the assumption that "error _must_ be caused by page
> >> > > update".
> >> > > No document/ABI about compress/decompress promised it. :)
> >
> > Indeed, I found no good documents about below errors that jiang.biao
> > pointed out.
> Hi, Peter
> The description about the errors comes from here,
> http://www.zlib.net/manual.html
> And about the error codes returned by inflate(), they are described as,
> ** inflate() returns
> Z_OK if some progress has been made (more input processed or more output
> produced),
> Z_STREAM_END if the end of the compressed data has been reached and all
> uncompressed output has been produced,
> Z_NEED_DICT if a preset dictionary is needed at this point,
> Z_DATA_ERROR if the input data was corrupted (input stream not conforming to
> the zlib format or incorrect check value, in which case strm->msg points to a
> string with a more specific error),
> Z_STREAM_ERROR if the stream structure was inconsistent (for example next_in
> or next_out was Z_NULL, or the state was inadvertently written over by the
> application),
> Z_MEM_ERROR if there was not enough memory,
> Z_BUF_ERROR if no progress was possible or if there was not enough room in
> the output buffer when Z_FINISH is used. ...
> **
Ah yes. My bad to be so uncareful. :)
> According to the above description, the error caused by page update looks
> more like tend to return Z_DATA_ERROR, but I do not have env to verify that.
> :)
> As I understand it, the real compress/decompress error cases other than that
> caused by page update should be rare, maybe the error code is enough to
> distinguish those if we can verify the the error codes returned by page update
> and other silent failures by test. If so, we can cut the cost of memcpy.
> If not, I agree with Guangrong's idea too. I never read the zlib code and all
> my
> information comes from the manual, so if anything inaccurate, pls ignore my
> option. :)
So I suppose all of us know that alternative now, we just need a solid
way to confirm the uncertainty. I'll leave this to Guangrong.
Thanks,
--
Peter Xu
- Re: [Qemu-devel] [PATCH 3/8] migration: support to detect compression and decompression errors, (continued)
- Re: [Qemu-devel] [PATCH 3/8] migration: support to detect compression and decompression errors, Peter Xu, 2018/03/21
- Re: [Qemu-devel] [PATCH 3/8] migration: support to detect compression and decompression errors, Xiao Guangrong, 2018/03/22
- Re: [Qemu-devel] [PATCH 3/8] migration: support to detect compression and decompression errors, Peter Xu, 2018/03/27
- Re: [Qemu-devel] [PATCH 3/8] migration: support to detect compression and decompression errors, Xiao Guangrong, 2018/03/27
- Re: [Qemu-devel] [PATCH 3/8] migration: support to detect compression and decompression errors, Peter Xu, 2018/03/27
- Re: [Qemu-devel] [PATCH 3/8] migration: support to detect compression and decompression errors, Xiao Guangrong, 2018/03/27
- Re: [Qemu-devel] [PATCH 3/8] migration: support to detectcompression and decompression errors, jiang.biao2, 2018/03/27
- Re: [Qemu-devel] [PATCH 3/8] migration: support to detectcompression and decompression errors, Xiao Guangrong, 2018/03/27
- Re: [Qemu-devel] [PATCH 3/8] migration: support to detectcompression and decompression errors, Peter Xu, 2018/03/27
- Re: [Qemu-devel] [PATCH 3/8] migration: support todetectcompression and decompression errors, jiang.biao2, 2018/03/28
- Re: [Qemu-devel] [PATCH 3/8] migration: support todetectcompression and decompression errors,
Peter Xu <=
- Re: [Qemu-devel] [PATCH 3/8] migration: support todetectcompression and decompression errors, Xiao Guangrong, 2018/03/28
- Re: [Qemu-devel] [PATCH 3/8] migration: support todetectcompressionand decompression errors, jiang.biao2, 2018/03/28
[Qemu-devel] [PATCH 4/8] migration: introduce control_save_page(), guangrong . xiao, 2018/03/13
[Qemu-devel] [PATCH 5/8] migration: move calling control_save_page to the common place, guangrong . xiao, 2018/03/13