Re: 6.6.78: timerlat_{hist,top} fail to build

[Guillaume Morin <guillaume@morinfr.org>]

On 19 Feb 16:03, Tomas Glozar wrote:
>
> Hello,
> 
> st 19. 2. 2025 v 15:48 odesílatel Guillaume Morin
> <guillaume@morinfr.org> napsal:
> >
> > Hello,
> >
> > The following patches prevent Linux 6.6.78+ rtla to build:
> >
> > - "rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads" (stable
> > commit 41955b6c268154f81e34f9b61cf8156eec0730c0)
> > - "rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads" (stable
> > commit 83b74901bdc9b58739193b8ee6989254391b6ba7)
> >
> > Both were added to Linux 6.6.78 based on the Fixes tag in the upstream
> > commits.
> >
> > These patches prevent 6.6.78 rta to build with a similar error (missing
> > kernel_workload in the params struct)
> > src/timerlat_top.c:687:52: error: ‘struct timerlat_top_params’ has no member named ‘kernel_workload’
> >
> 
> I did not realize that, sorry!
> 
> > These patches appear to depend on "rtla/timerlat: Make user-space
> > threads the default" commit fb9e90a67ee9a42779a8ea296a4cf7734258b27d
> > which is not present in 6.6.
> >
> > I am not sure if it's better to revert them or pick up
> > fb9e90a67ee9a42779a8ea296a4cf7734258b27d in 6.6. Tomas, what do you
> > think?
> >
> 
> We don't want to pick up fb9e90a67ee9a42779a8ea296a4cf7734258b27d
> (rtla/timerlat: Make user-space threads the default) to stable, since
> it changes the default behavior as well as output of rtla.
> 
> The patches can be fixed by by substituting params->kernel_workload
> for !params->user_hist (!params->user_top) for the version of the
> files that is present in 6.6-stable (6.1-stable is not affected, since
> it doesn't have user workload mode at all).
> 
> I'm not sure what the correct procedure would be. One way I can think
> of is reverting the patch as broken, and me sending an alternate
> version of the patch for 6.6-stable containing the change above. That
> would be the cleanest way in my opinion (as compared to sending the
> fixup directly).

Either way would work for me. Not sure what Greg prefers however

-- 
Guillaume Morin <guillaume@morinfr.org>