Messages in this thread | | | Date | Sat, 19 Nov 2011 00:10:39 +0800 | From | annie li <> | Subject | Re: [Xen-devel] Re: [PATCH 2/3] xen/granttable: Grant tables V2 implementation |
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On 2011-11-18 22:00, Ian Campbell wrote: > On Fri, 2011-11-18 at 13:52 +0000, Konrad Rzeszutek Wilk wrote: > >>>> + xen_raw_printk(str); >>>> + panic(str); >>>> >>> I expect you've just copied this style from elsewhere but I really >>> dislike this duplication of prints. If panic is not useful here we >>> really ought to address that at the root instead of going around >>> patching things to print every panic message twice. I thought >>> earlyprintk was supposed to solve this problem. Perhaps a generic >>> early_panic_print could be added to the panic code? >>> >> We are using this combo in swiotlb-xen and as well in the xen pci. >> We could declere a 'xen_raw_panic' that would do the job? >> >> The problem is that panic() uses the "late" printk mechanism (so >> it goes through the buffer that ends up not beign flushed) and the >> panic never sees the light. >> > > So lets fix that instead of working around it... > > >> The 'xen_raw_printk' is synchronous.. >> >> But I wonder if the panic surfaces if 'earlyprintk=xen' is used? >> At which point it might be that the those extra xen_raw_printk >> become pointless? >> > > I think panic's do come out with earlyprintk (unless they are truly > super early). > So we have two candidates: xen_raw_printk + panic panic + earlyprintk=xen
If panic does work with earlyprintk, then the latter one is better. Otherwise, there will be duplicated string printed out with 'earlyprintk=xen'.
Thanks Annie > Ian. > > > >
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