[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v3 2/5] remus: resume immediately if libxl__xc_domain_save_done() completes
On Fri, 2016-01-15 at 13:44 +0800, Wen Congyang wrote: > On 01/14/2016 06:21 PM, Ian Campbell wrote: > > On Tue, 2016-01-12 at 09:40 +0800, Wen Congyang wrote: > > > On 01/09/2016 12:27 AM, Ian Campbell wrote: > > > > On Fri, 2016-01-08 at 14:38 +0800, Wen Congyang wrote: > > > > > For example: if the secondary host is down, and we fail to send > > > > > the > > > > > data > > > > > to > > > > > the secondary host. xc_domain_save() returns 0. > > > > > > > > Just to be check: On failure in this way xc_domain_save() returns 0 > > > > (i.e. > > > > success)? > > > > > > Yes, it returns 0. I am not sure the return value is right. > > > > > > > > > > > > ÂSo in the function > > > > > libxl__xc_domain_save_done(), rc is 0(the helper program exits > > > > > normally), > > > > > and retval is 0(it is xc_domain_save()'s return value). In such > > > > > case, > > > > > we > > > > > just need to complete the stream. > > > > > > > > > > Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx> > > > > > --- > > > > > Âtools/libxl/libxl_stream_write.c | 13 +++++++++++-- > > > > > Â1 file changed, 11 insertions(+), 2 deletions(-) > > > > > > > > > > diff --git a/tools/libxl/libxl_stream_write.c > > > > > b/tools/libxl/libxl_stream_write.c > > > > > index 80d9208..82e7719 100644 > > > > > --- a/tools/libxl/libxl_stream_write.c > > > > > +++ b/tools/libxl/libxl_stream_write.c > > > > > @@ -354,8 +354,17 @@ void libxl__xc_domain_save_done(libxl__egc > > > > > *egc, > > > > > void *dss_void, > > > > > ÂÂÂÂÂÂ* alive, and check_all_finished() may have torn it down > > > > > around > > > > > us. > > > > > ÂÂÂÂÂÂ* If the stream is not still alive, we must not continue > > > > > any > > > > > work. > > > > > ÂÂÂÂÂÂ*/ > > > > > -ÂÂÂÂif (libxl__stream_write_inuse(stream)) > > > > > -ÂÂÂÂÂÂÂÂwrite_emulator_xenstore_record(egc, stream); > > > > > +ÂÂÂÂif (libxl__stream_write_inuse(stream)) { > > > > > +ÂÂÂÂÂÂÂÂif (dss->remus) > > > > > +ÂÂÂÂÂÂÂÂÂÂÂÂ/* > > > > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂ* For remus, if libxl__xc_domain_save_done() > > > > > completes, > > > > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂ* there was an error sending data to the secondary. > > > > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂ* Resume the primary ASAP. > > > > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂ*/ > > > > > +ÂÂÂÂÂÂÂÂÂÂÂÂstream_complete(egc, stream, 0); > > > > > > > > Is there an indication to the caller that things have failed in > > > > this > > > > way? > > > > Would that information be of use to the caller? > > > > > > For remus, when we come here, something is wrong regardless of the > > > return > > > value. > > > > But does the caller know this? Can it tell. > > > > > > > > > > > > > Or does the called infer this has happened because > > > > otherwise libxl_domain_remus_start is not supposed to return? > > > > > > Yes, libxl_domain_remus_start() should not return unless somethins is > > > wrong. > > > > This really ought to be documented somewhere. > > libxl_domain_remus_start(): > ÂÂÂÂ/* Point of no return */ > ÂÂÂÂlibxl__remus_setup(egc, dss); > ÂÂÂÂreturn AO_INPROGRESS; This is (obviously) not documentation. _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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