Re: [Xen-devel] [PATCH] trace: Fix incorrect number of pages used for trace metadata

[Igor Druzhinin <igor.druzhinin@xxxxxxxxxx>]

Checked that.

Tested-by: Igor Druzhinin <igor.druzhinin@xxxxxxxxxx>

On 30/09/16 17:12, George Dunlap wrote:
> On 30/09/16 17:04, Igor Druzhinin wrote:
> > On 30/09/16 15:46, George Dunlap wrote:
> > > On 29/09/16 14:53, Igor Druzhinin wrote:
> > > > As long as t_info_first_offset is calculated in uint32_t offsets we
> > > > need to
> > > > multiply it by sizeof(uint32_t) in order to get the right number of
> > > > pages
> > > > for trace metadata. Not doing that makes it impossible to read the trace
> > > > buffer correctly from userspace for some corner cases.
> > > >
> > > > Signed-off-by: Igor Druzhinin <igor.druzhinin@xxxxxxxxxx>
> > > Hmm, looks like we actually want to revert this c/s fbf96e6, "xentrace:
> > > correct formula to calculate t_info_pages".  But that one was presumably
> > > written (and Acked by me) because the variable name there,
> > > t_info_first_offset, is confusing.
> > >
> > > The other mistake in fbf96e6 is that before t_info_words was actually
> > > denominated in words; but after it's denominated in bytes (which is
> > > again confusing).
> > >
> > > What about something like the attached instead?  This should fix your
> > > problem while making the code clearer.
> > >
> > >  -George
> > Reviewed-by: Igor Druzhinin <igor.druzhinin@xxxxxxxxxx>
> Thanks.  Any chance I could get a Tested-by as well? :-)
>
>  -George
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