[PATCH v3 0/7] Remove unneeded build directory traversals

[PATCH v3 0/7] Remove unneeded build directory traversals

[Andrew F. Davis]

Hello all,

I was building a kernel for x86 and noticed Make still descended into
directories like drivers/gpu/drm/hisilicon, this seems kind of odd given
nothing will be built here. It looks to be due to some directories being
included in obj-y unconditionally instead of only when the relevant
CONFIG_ is set.

These patches are split by subsystem in-case, for some reason, a file in
a directory does need to be built, I believe I have checked for all
instances of this, but a quick review from some maintainers would be nice.

Thanks,
Andrew

Changes from v2:
 - Removed patches that would not work
 - Rebased on v4.11-rc1 (no changes needed)

Changes from v1:
 - Removed patches already taken by maintainers
 - Rebased on v4.10-rc1 (no changes needed)

Andrew F. Davis (7):
  pwm: Only descend into pwm directory when CONFIG_PWM is set
  amba: Only descend into amba directory when CONFIG_ARM_AMBA is set
  NFC: Only descend into nfc directory when CONFIG_NFC is set
  macintosh: Only descend into directory when CONFIG_MACINTOSH_DRIVERS
    is set
  auxdisplay: Only descend into directory when CONFIG_AUXDISPLAY is set
  lguest: Only descend into lguest directory when CONFIG_LGUEST is set
  mmc: Only descend into mmc directory when CONFIG_MMC is set

 drivers/Makefile | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

-- 
2.11.0

[PATCH v3 1/7] pwm: Only descend into pwm directory when CONFIG_PWM is set

[Andrew F. Davis]

When CONFIG_PWM is not set make will still descend into the pwm
directory but nothing will be built. This produces unneeded build
artifacts and messages in addition to slowing the build. Fix this here.

Signed-off-by: Andrew F. Davis <afd@ti.com>
---
 drivers/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/Makefile b/drivers/Makefile
index 2eced9afba53..00d86749a843 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -13,7 +13,7 @@ obj-$(CONFIG_GENERIC_PHY)	+= phy/
 # GPIO must come after pinctrl as gpios may need to mux pins etc
 obj-$(CONFIG_PINCTRL)		+= pinctrl/
 obj-$(CONFIG_GPIOLIB)		+= gpio/
-obj-y				+= pwm/
+obj-$(CONFIG_PWM)		+= pwm/
 obj-$(CONFIG_PCI)		+= pci/
 # PCI dwc controller drivers
 obj-y				+= pci/dwc/
-- 
2.11.0

[PATCH v3 2/7] amba: Only descend into amba directory when CONFIG_ARM_AMBA is set

[Andrew F. Davis]

When CONFIG_ARM_AMBA is not set make will still descend into the amba
directory but nothing will be built. This produces unneeded build
artifacts and messages in addition to slowing the build. Fix this here.

Signed-off-by: Andrew F. Davis <afd@ti.com>
---
 drivers/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/Makefile b/drivers/Makefile
index 00d86749a843..23712a92a89a 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -31,7 +31,7 @@ obj-$(CONFIG_SFI)		+= sfi/
 # PnP must come after ACPI since it will eventually need to check if acpi
 # was used and do nothing if so
 obj-$(CONFIG_PNP)		+= pnp/
-obj-y				+= amba/
+obj-$(CONFIG_ARM_AMBA)		+= amba/
 
 obj-y				+= clk/
 # Many drivers will want to use DMA so this has to be made available
-- 
2.11.0

[PATCH v3 3/7] NFC: Only descend into nfc directory when CONFIG_NFC is set

[Andrew F. Davis]

When CONFIG_NFC is not set make will still descend into the nfc
directory but nothing will be built. This produces unneeded build
artifacts and messages in addition to slowing the build. Fix this here.

Signed-off-by: Andrew F. Davis <afd@ti.com>
---
 drivers/Makefile | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/Makefile b/drivers/Makefile
index 23712a92a89a..9cf52524ecab 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -69,7 +69,11 @@ obj-$(CONFIG_FB_INTEL)          += video/fbdev/intelfb/
 
 obj-$(CONFIG_PARPORT)		+= parport/
 obj-$(CONFIG_NVM)		+= lightnvm/
-obj-y				+= base/ block/ misc/ mfd/ nfc/
+obj-y				+= base/
+obj-y				+= block/
+obj-y				+= misc/
+obj-y				+= mfd/
+obj-$(CONFIG_NFC)		+= nfc/
 obj-$(CONFIG_LIBNVDIMM)		+= nvdimm/
 obj-$(CONFIG_DEV_DAX)		+= dax/
 obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf/
-- 
2.11.0

[PATCH v3 4/7] macintosh: Only descend into directory when CONFIG_MACINTOSH_DRIVERS is set

[Andrew F. Davis]

When CONFIG_MACINTOSH_DRIVERS is not set make will still descend into the
macintosh directory but nothing will be built. This produces unneeded
build artifacts and messages in addition to slowing the build.
Fix this here.

Signed-off-by: Andrew F. Davis <afd@ti.com>
---
 drivers/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/Makefile b/drivers/Makefile
index 9cf52524ecab..cd92491bd76b 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -78,7 +78,7 @@ obj-$(CONFIG_LIBNVDIMM)		+= nvdimm/
 obj-$(CONFIG_DEV_DAX)		+= dax/
 obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf/
 obj-$(CONFIG_NUBUS)		+= nubus/
-obj-y				+= macintosh/
+obj-$(CONFIG_MACINTOSH_DRIVERS)	+= macintosh/
 obj-$(CONFIG_IDE)		+= ide/
 obj-$(CONFIG_SCSI)		+= scsi/
 obj-y				+= nvme/
-- 
2.11.0

Re: [PATCH v3 4/7] macintosh: Only descend into directory when CONFIG_MACINTOSH_DRIVERS is set

[Michael Ellerman]

"Andrew F. Davis" <afd@ti.com> writes:

> When CONFIG_MACINTOSH_DRIVERS is not set make will still descend into the
> macintosh directory but nothing will be built. This produces unneeded
> build artifacts and messages in addition to slowing the build.
> Fix this here.
>
> Signed-off-by: Andrew F. Davis <afd@ti.com>
> ---
>  drivers/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

LGTM.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>

cheersj

[PATCH v3 5/7] auxdisplay: Only descend into directory when CONFIG_AUXDISPLAY is set

[Andrew F. Davis]

When CONFIG_AUXDISPLAY is not set make will still descend into the
auxdisplay directory but nothing will be built. This produces unneeded
build artifacts and messages in addition to slowing the build.
Fix this here.

Signed-off-by: Andrew F. Davis <afd@ti.com>
---
 drivers/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/Makefile b/drivers/Makefile
index cd92491bd76b..8a9ed5c59778 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -95,7 +95,7 @@ obj-y				+= firewire/
 obj-$(CONFIG_UIO)		+= uio/
 obj-$(CONFIG_VFIO)		+= vfio/
 obj-y				+= cdrom/
-obj-y				+= auxdisplay/
+obj-$(CONFIG_AUXDISPLAY)	+= auxdisplay/
 obj-$(CONFIG_PCCARD)		+= pcmcia/
 obj-$(CONFIG_DIO)		+= dio/
 obj-$(CONFIG_SBUS)		+= sbus/
-- 
2.11.0

[PATCH v3 6/7] lguest: Only descend into lguest directory when CONFIG_LGUEST is set

[Andrew F. Davis]

When CONFIG_LGUEST is not set make will still descend into the lguest
directory but nothing will be built. This produces unneeded build
artifacts and messages in addition to slowing the build. Fix this here.

Signed-off-by: Andrew F. Davis <afd@ti.com>
---
 drivers/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/Makefile b/drivers/Makefile
index 8a9ed5c59778..3d758020d248 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -126,7 +126,7 @@ obj-$(CONFIG_ACCESSIBILITY)	+= accessibility/
 obj-$(CONFIG_ISDN)		+= isdn/
 obj-$(CONFIG_EDAC)		+= edac/
 obj-$(CONFIG_EISA)		+= eisa/
-obj-y				+= lguest/
+obj-$(CONFIG_LGUEST)		+= lguest/
 obj-$(CONFIG_CPU_FREQ)		+= cpufreq/
 obj-$(CONFIG_CPU_IDLE)		+= cpuidle/
 obj-y				+= mmc/
-- 
2.11.0

[PATCH v3 7/7] mmc: Only descend into mmc directory when CONFIG_MMC is set

[Andrew F. Davis]

When CONFIG_MMC is not set make will still descend into the mmc
directory but nothing will be built. This produces unneeded build
artifacts and messages in addition to slowing the build. Fix this here.

Signed-off-by: Andrew F. Davis <afd@ti.com>
---
 drivers/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/Makefile b/drivers/Makefile
index 3d758020d248..03da7a38e989 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -129,7 +129,7 @@ obj-$(CONFIG_EISA)		+= eisa/
 obj-$(CONFIG_LGUEST)		+= lguest/
 obj-$(CONFIG_CPU_FREQ)		+= cpufreq/
 obj-$(CONFIG_CPU_IDLE)		+= cpuidle/
-obj-y				+= mmc/
+obj-$(CONFIG_MMC)		+= mmc/
 obj-$(CONFIG_MEMSTICK)		+= memstick/
 obj-$(CONFIG_NEW_LEDS)		+= leds/
 obj-$(CONFIG_INFINIBAND)	+= infiniband/
-- 
2.11.0

Re: [PATCH v3 7/7] mmc: Only descend into mmc directory when CONFIG_MMC is set

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 868 bytes --]

Hi Andrew,

[auto build test ERROR on linus/master]
[also build test ERROR on v4.11-rc2 next-20170310]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Andrew-F-Davis/Remove-unneeded-build-directory-traversals/20170318-040719
config: x86_64-rhel (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

>> ERROR: "sdhci_pci_get_data" [drivers/mmc/host/sdhci-pci.ko] undefined!
>> ERROR: "sdhci_pci_spt_drive_strength" [drivers/mmc/host/sdhci-pci.ko] undefined!

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 38835 bytes --]

Re: [PATCH v3 7/7] mmc: Only descend into mmc directory when CONFIG_MMC is set

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 949 bytes --]

Hi Andrew,

[auto build test ERROR on linus/master]
[also build test ERROR on v4.11-rc2 next-20170310]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Andrew-F-Davis/Remove-unneeded-build-directory-traversals/20170318-040719
config: x86_64-allmodconfig (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   arch/x86/built-in.o: In function `mrfld_sd_init':
>> platform_mrfld_sd.c:(.init.text+0x397d5): undefined reference to `sdhci_pci_get_data'
   platform_mrfld_sd.c:(.init.text+0x397e3): undefined reference to `sdhci_pci_get_data'

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 58848 bytes --]

Re: [PATCH v3 0/7] Remove unneeded build directory traversals

[Arnd Bergmann]

On Wed, Mar 15, 2017 at 5:37 PM, Andrew F. Davis <afd@ti.com> wrote:
> Hello all,
>
> I was building a kernel for x86 and noticed Make still descended into
> directories like drivers/gpu/drm/hisilicon, this seems kind of odd given
> nothing will be built here. It looks to be due to some directories being
> included in obj-y unconditionally instead of only when the relevant
> CONFIG_ is set.
>
> These patches are split by subsystem in-case, for some reason, a file in
> a directory does need to be built, I believe I have checked for all
> instances of this, but a quick review from some maintainers would be nice.

I didn't see anything wrong with the patches, and made sure that there
are no tristate symbols controlling the subdirectory for anything that
requires a built-in driver (which would cause a link failure).

I'm not sure about drivers/lguest, which has some special magic
in its Makefile, it's possible that this now fails with CONFIG_LGUEST=m.

      Arnd

Re: [PATCH v3 0/7] Remove unneeded build directory traversals

[Andrew F. Davis]

On 03/15/2017 04:03 PM, Arnd Bergmann wrote:
> On Wed, Mar 15, 2017 at 5:37 PM, Andrew F. Davis <afd@ti.com> wrote:
>> Hello all,
>>
>> I was building a kernel for x86 and noticed Make still descended into
>> directories like drivers/gpu/drm/hisilicon, this seems kind of odd given
>> nothing will be built here. It looks to be due to some directories being
>> included in obj-y unconditionally instead of only when the relevant
>> CONFIG_ is set.
>>
>> These patches are split by subsystem in-case, for some reason, a file in
>> a directory does need to be built, I believe I have checked for all
>> instances of this, but a quick review from some maintainers would be nice.
> 
> I didn't see anything wrong with the patches, and made sure that there
> are no tristate symbols controlling the subdirectory for anything that
> requires a built-in driver (which would cause a link failure).
> 
> I'm not sure about drivers/lguest, which has some special magic
> in its Makefile, it's possible that this now fails with CONFIG_LGUEST=m.
> 

lguest and mmc are the strange ones, so I put them last in the series in
case they did need to be dropped.

lguest was supposed to have been taken from v1:
https://lkml.org/lkml/2016/6/20/1086
but it looks like it didn't so I re-introduced it for v3.

mmc caught some 0-day build warnings but I never got to the bottom of them.

Anyway, I have no problem with these two being held back until the magic
in their Makefile is sorted out.

Thanks,
Andrew

>       Arnd
> 

Re: [PATCH v3 0/7] Remove unneeded build directory traversals

[Arnd Bergmann]

On Wed, Mar 15, 2017 at 10:15 PM, Andrew F. Davis <afd@ti.com> wrote:
> On 03/15/2017 04:03 PM, Arnd Bergmann wrote:
>> On Wed, Mar 15, 2017 at 5:37 PM, Andrew F. Davis <afd@ti.com> wrote:
>>> Hello all,
>>>
>>> I was building a kernel for x86 and noticed Make still descended into
>>> directories like drivers/gpu/drm/hisilicon, this seems kind of odd given
>>> nothing will be built here. It looks to be due to some directories being
>>> included in obj-y unconditionally instead of only when the relevant
>>> CONFIG_ is set.
>>>
>>> These patches are split by subsystem in-case, for some reason, a file in
>>> a directory does need to be built, I believe I have checked for all
>>> instances of this, but a quick review from some maintainers would be nice.
>>
>> I didn't see anything wrong with the patches, and made sure that there
>> are no tristate symbols controlling the subdirectory for anything that
>> requires a built-in driver (which would cause a link failure).
>>
>> I'm not sure about drivers/lguest, which has some special magic
>> in its Makefile, it's possible that this now fails with CONFIG_LGUEST=m.
>>
>
> lguest and mmc are the strange ones, so I put them last in the series in
> case they did need to be dropped.
>
> lguest was supposed to have been taken from v1:
> https://lkml.org/lkml/2016/6/20/1086
> but it looks like it didn't so I re-introduced it for v3.
>
> mmc caught some 0-day build warnings but I never got to the bottom of them.

Ah, I see now what happened to mmc:

obj-$(subst m,y,$(CONFIG_MMC))  += host/
tmio_mmc_core-$(subst m,y,$(CONFIG_MMC_SDHI))   += tmio_mmc_dma.o
obj-$(subst m,y,$(CONFIG_MMC_SDHCI_PCI))        += sdhci-pci-data.o

with CONFIG_MMC=m, this will fail to build the built-in files in
drivers/mmc/host. I suppose this could be expressed in a different
way these days, but dropping the patch would be easier.

     Arnd