Re: Backport perf makefile fix to linux-6.6.y

["Alexis Lothoré" <alexis.lothore@bootlin.com>]

On Wed Jul 9, 2025 at 12:39 PM CEST, Greg KH wrote:
> On Wed, Jul 09, 2025 at 12:19:01PM +0200, Alexis Lothoré wrote:
>> Hello stable team,
>> 
>> could you please backport commit 440cf77625e3 ("perf: build: Setup
>> PKG_CONFIG_LIBDIR for cross compilation") to linux-6.6.y ?
>> 
>> Its absence prevents some people from building the perf tool in cross-compile
>> environment with this kernel. The patch applies cleanly on linux-6.6.y
>
> Is this a regression from older kernels that was broken in 6.6.y, or is
> this a new feature?  If a new feature, why not just use perf from a
> newer kernel version instead?

I manage to build perf with a 5.15.x kernel, while I can't in 6.6 (with the
same parameters), so yes, I would call it a regression.
To clarify my wording, when I say that missing this patch prevents from
building perf, it actually _breaks_ perf build, when trying to build it
with libtraceevent support:
 
In file included from /home/alexis/src/buildroot/output/build/linux-6.6.94/tools/perf//util/session.h:5,
                 from builtin-c2c.c:29:
/home/alexis/src/buildroot/output/build/linux-6.6.94/tools/perf//util/trace-event.h:149:62: error: operator '&&' has no right operand
  149 | #if defined(LIBTRACEEVENT_VERSION) &&  LIBTRACEEVENT_VERSION >= MAKE_LIBTRACEEVENT_VERSION(1, 5, 0)

Alexis

> thanks,
>
> greg k-h




-- 
Alexis Lothoré, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com