Re: [PATCH v1 2/3] selftests/nolibc: fix up O= option support

From: Zhangjin Wu
Date: Fri Aug 04 2023 - 15:17:47 EST


> On Sat, Aug 05, 2023 at 02:40:23AM +0800, Zhangjin Wu wrote:
> > > On Fri, Aug 04, 2023 at 07:51:50PM +0200, Thomas Wei?schuh wrote:
> > > > On 2023-08-05 00:29:10+0800, Zhangjin Wu wrote:
> > [...]
> > > > > Do you mean here?
> > > > >
> > > > > # kernel image names by architecture
> > > > > IMAGE_i386 = arch/x86/boot/bzImage
> > > > > IMAGE_x86 = arch/x86/boot/bzImage
> > > > > IMAGE_arm64 = arch/arm64/boot/Image
> > > > > IMAGE_arm = arch/arm/boot/zImage
> > > > > IMAGE_mips = vmlinuz
> > > > > IMAGE_riscv = arch/riscv/boot/Image
> > > > > IMAGE = $(IMAGE_$(ARCH))
> > > > > IMAGE_NAME = $(notdir $(IMAGE))
> > > > >
> > > > > It does save another KERNEL_IMAGE macro in my future patch ;-)
> > > > >
> > > > > But without O=, OUTPUT is also empty like objtree and when empty, it is
> > > > > assigned as $(CURDIR), not $(srctree) as we expected for IMAGE and .config. To
> > > > > be cleaner, objtree should also be used:
> > > > >
> > > > > - IMAGE = $(IMAGE_$(ARCH))
> > > > > + IMAGE = $(objtree)/$(IMAGE_$(ARCH))
> > > > >
> > > > > Is this what you want?
> > > >
> > > > More like:
> > > >
> > > > - $(Q)qemu-system-$(QEMU_ARCH) -display none -no-reboot -kernel "$(srctree)/$(IMAGE)" -serial stdio $(QEMU_ARGS) > "$(CURDIR)/run.out"
> > > > + $(Q)qemu-system-$(QEMU_ARCH) -display none -no-reboot -kernel "$(OUTPUT)$(IMAGE)" -serial stdio $(QEMU_ARGS) > "$(CURDIR)/run.out"
> > > >
> > > > My assumption was that it's weird that we need to define such variables
> > > > ourselves.
> > > >
> > > > Using an empty $(OUTPUT) would have been fine if make is run from the
> > > > root of the kernel tree. But that is not the case.
> > > >
> > > > It still feels weird but I can't think of a nicer way, and it's not
> > > > a big issue. So let's keep that part the same.
> > > >
> > > > Or maybe Willy has a better idea.
> > >
> > > I've just glanced over the discussion, but I'm wondering, why not
> > > "$(objtree)/$(IMAGE)" instead ?
> > >
> >
> > We used "$(objtree)/$(IMAGE)" originally, I thought of Thomas asked me to
> > further add "$(objtree)" in the first place of IMAGE,
> >
> > - IMAGE = $(IMAGE_$(ARCH))
> > + IMAGE = $(objtree)/$(IMAGE_$(ARCH))
> >
> > And then, we can use "IMAGE" directly in the qemu run & rerun targets:
> >
> > # run the tests after building the kernel
> > run: kernel
> > - $(Q)qemu-system-$(QEMU_ARCH) -display none -no-reboot -kernel "$(objtree)/$(IMAGE)" -serial stdio $(QEMU_ARGS) > "$(RUN_OUT)"
> > + $(Q)qemu-system-$(QEMU_ARCH) -display none -no-reboot -kernel "$(IMAGE)" -serial stdio $(QEMU_ARGS) > "$(RUN_OUT)"
> > $(Q)$(REPORT) "$(RUN_OUT)"
> >
> > # re-run the tests from an existing kernel
> > rerun:
> > - $(Q)qemu-system-$(QEMU_ARCH) -display none -no-reboot -kernel "$(objtree)/$(IMAGE)" -serial stdio $(QEMU_ARGS) > "$(RUN_OUT)"
> > + $(Q)qemu-system-$(QEMU_ARCH) -display none -no-reboot -kernel "$(IMAGE)" -serial stdio $(QEMU_ARGS) > "$(RUN_OUT)"
> > $(Q)$(REPORT) "$(RUN_OUT)"
> >
> > Which one do you prefer? will renew this series soon.
>
> It's not a matter of preference but which solution really works. In short
> it should work fine and consistently when launched from topdir and from
> the nolibc-test dir. I personally don't know the effect of O= when run
> from a subdir (is it relative to the current dir or topdir?).
>

As suggested by Thomas, $(COMMAND_O) will be used to pass the absolute
$(O) for every sub $(MAKE), O= will work like this:

// subdir
$ pwd
/labs/linux-lab/src/linux-stable/tools/testing/selftests/nolibc
$ mkdir -p out
$ make run-user O=out -C /labs/linux-lab/src/linux-stable/tools/testing/selftests/nolibc/ -j4 | grep status
Makefile:122: srctree=/labs/linux-lab/src/linux-stable
Makefile:123: objtree: out
Makefile:124: COMMAND_O: O=/labs/linux-lab/src/linux-stable/tools/testing/selftests/nolibc/out
Makefile:125: OUTPUT=/labs/linux-lab/src/linux-stable/tools/testing/selftests/nolibc/out/
166 test(s): 158 passed, 8 skipped, 0 failed => status: warning

// topdir
$ pwd
/labs/linux-lab/src/linux-stable
$ mkdir -p out
$ make run-user O=out -C /labs/linux-lab/src/linux-stable/tools/testing/selftests/nolibc/ -j4 | grep status
Makefile:122: srctree=/labs/linux-lab/src/linux-stable
Makefile:123: objtree: out
Makefile:124: COMMAND_O: O=/labs/linux-lab/src/linux-stable/out
Makefile:125: OUTPUT=/labs/linux-lab/src/linux-stable/out/
166 test(s): 158 passed, 8 skipped, 0 failed => status: warning

// outside
$ pwd
/labs/linux-lab/build
$ mkdir -p out
$ make run-user O=out -C /labs/linux-lab/src/linux-stable/tools/testing/selftests/nolibc/ -j4 | grep status
Makefile:122: srctree=/labs/linux-lab/src/linux-stable
Makefile:123: objtree: out
Makefile:124: COMMAND_O: O=/labs/linux-lab/build/out
Makefile:125: OUTPUT=/labs/linux-lab/build/out/
166 test(s): 158 passed, 8 skipped, 0 failed => status: warning

The change:

$ grep COMMAND_O -ur tools/testing/selftests/nolibc/Makefile
$(Q)$(MAKE) -C ../../../include/nolibc $(COMMAND_O) ARCH=$(ARCH) OUTPUT=$(OUTPUT)sysroot/ headers_standalone
$(Q)$(MAKE) -C $(srctree) $(COMMAND_O) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) mrproper $(DEFCONFIG) prepare
$(Q)$(MAKE) -C $(srctree) $(COMMAND_O) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) $(IMAGE_NAME) CONFIG_INITRAMFS_SOURCE=$(CURDIR)/initramfs

> > And even further, I thought of puting everything to $(OUTPUT), but the
> > change is very ugly and not good for v6.6, If you like, I will send that
> > patch only as a discuss stuff.
>
> Yeah I'd rather avoid ugly things for 6.6 now.
>

Ok, since you also suggested let's develop in outside directory, it is better
to reserve the left parts as-is ;-)

> Thanks,
> Willy