[lttng-dev] lttng-modules build error against linux 3.18.x longterm kernels

[Bjørn Forsman]

Hi all,

(I'm not subscribed, please CC me.)

Build error snippet:

[...]
 CC [M]  /tmp/nix-build-lttng-modules-2.6.0-5-g1b2a542-3.18.10.drv-0/lttng-modules-1b2a542/probes/lttng-probe-irq.o
 CC [M]  /tmp/nix-build-lttng-modules-2.6.0-5-g1b2a542-3.18.10.drv-0/lttng-modules-1b2a542/probes/lttng-probe-timer.o
 CC [M]  /tmp/nix-build-lttng-modules-2.6.0-5-g1b2a542-3.18.10.drv-0/lttng-modules-1b2a542/probes/lttng-probe-kmem.o
In file included from
/tmp/nix-build-lttng-modules-2.6.0-5-g1b2a542-3.18.10.drv-0/lttng-modules-1b2a542/probes/../instrumentation/events/lttng-module/../../../probes/define_trace.h:136:0,
                from
/tmp/nix-build-lttng-modules-2.6.0-5-g1b2a542-3.18.10.drv-0/lttng-modules-1b2a542/probes/../instrumentation/events/lttng-module/kmem.h:466,
                from
/tmp/nix-build-lttng-modules-2.6.0-5-g1b2a542-3.18.10.drv-0/lttng-modules-1b2a542/probes/lttng-probe-kmem.c:42:
/tmp/nix-build-lttng-modules-2.6.0-5-g1b2a542-3.18.10.drv-0/lttng-modules-1b2a542/probes/../instrumentation/events/lttng-module/../../../probes/lttng-events.h:180:6:
error: conflicting types for 'trace_mm_page_alloc_extfrag'
void trace_##_name(_proto);
     ^
/tmp/nix-build-lttng-modules-2.6.0-5-g1b2a542-3.18.10.drv-0/lttng-modules-1b2a542/probes/../instrumentation/events/lttng-module/../../../probes/lttng-events.h:47:2:
note: in expansion of macro 'LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP'
 LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP(map, name, map, PARAMS(proto),
PARAMS(args))
[...]

Build results from the NixOS build server[1] (which contains full
logs) seems to indicate that this breakage started with the linux
3.18.9 -> 3.18.10 transition. Simultaneously, lttng-modules was
updated 2.6.0-rc1 -> 2.6.0-5-g1b2a542 (latest on stable-2.6 branch),
but I guess/hope that's not the reason for the error :-)

[1]: http://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.linuxPackages_3_18.lttng-modules.i686-linux

Best regards,
Bjørn Forsman