stage1/kvm: Improve QEMU Makefile rules #3474
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QEMU was constantly re-configured and built for every make. This is not necessary. The root cause was the CONF stamp stage, which was the target for the git clone and then configure steps, but had no rule to actually generate the stamp file, so made the configure stage think we had always just cloned (in effect). Remove the CLONE stamp stage, and make the git clone directly trigger the configure step.
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@krnowak PTAL |
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CC @lucab - not sure if krnowak is the correct reviewer for this - but seems to be the makelib and thus makefile/build system owner? |
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@grahamwhaley yep, @krnowak made the makelib but he's only sporadically around. The specific I have generic knowledge of the build system but not of this specific makefile, however overall this LGTM. |
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@grahamwhaley Big up for this PR, I've been thinking about this issue. What step exactly determines if qemu will be configured & built for each make or not? Is it |
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Hi @jjlakis - yes, afaict the GCL_TARGET pointed at the CLONE_STAMP, but there was no actual rule to make the CLONE_STAMP, so it always saw that stamp file as missing, so always did a reconfig that then made a rebuild happen. It took some 'make -d V=3' and squinting, and time, to try and figure that out ;-) |
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Good job, LGTM. |
QEMU would always be configured and built for every make. Fix this to reduce the development cycle.
This fix is also desirable for a follow on patchset that adds the ability in the QEMU Makefile to apply patches to QEMU before building.