On Fri, Jun 23, 2017 at 02:31:40PM +0900, Masahiro Yamada wrote: > Hi Nicholas, > > 2017-06-23 0:50 GMT+09:00 Nicholas Piggin <npiggin@xxxxxxxxx>: > > On Thu, 22 Jun 2017 08:18:38 +0200 > > Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote: > > > >> On Wed, Jun 21, 2017 at 10:55:06PM +0200, Arnd Bergmann wrote: > >> > On Wed, Jun 21, 2017 at 8:08 PM, Nicholas Piggin <npiggin@xxxxxxxxx> wrote: > >> > > On Wed, 21 Jun 2017 09:19:13 -0700 > >> > > Stephen Boyd <sboyd@xxxxxxxxxxxxxx> wrote: > >> > >> On 06/21, Arnd Bergmann wrote: > >> > >> > >> > >> Ok. Can you send a revert patch to the list with some information > >> > >> on why we can't do the hack anymore and also Cc lkml/kbuild > >> > >> lists? The commit is in linux-next now as commit 06e226c7fb23 > >> > >> (clk: sunxi-ng: Move all clock types to a library, 2017-06-02). > >> > >> > >> > > > >> > > I grabbed this patch and applied it to the kbuid/thin-ac tree. I tested > >> > > with thin archives enabled and disabled with arm defconfig which ends up > >> > > setting CONFIG_SUNXI_CCU=y. > >> > > > >> > > The patch makes no difference to vmlinux size whether using traditional > >> > > incremental link, or thin archives (there is a small difference between > >> > > inclink and thinarc but that's unrelated). > >> > > > >> > > So this thin archives change does not break your patch, it's just that > >> > > it doesn't really do the right thing. I like the general idea, but we > >> > > need to work out how to make it properly supported by the build system. > >> > > > >> > > With the patch applied, this is what the build system currently does: > >> > > > >> > > arm-linux-gnueabihf-ld -EL -r -o drivers/clk/sunxi-ng/built-in.o drivers/clk/sunxi-ng/ccu-sun5i.o drivers/clk/sunxi-ng/ccu-sun6i-a31.o drivers/clk/sunxi-ng/ccu-sun8i-a23.o drivers/clk/sunxi-ng/ccu-sun8i-a33.o drivers/clk/sunxi-ng/ccu-sun8i-h3.o drivers/clk/sunxi-ng/ccu-sun8i-v3s.o drivers/clk/sunxi-ng/ccu-sun8i-r.o drivers/clk/sunxi-ng/ccu-sun9i-a80.o drivers/clk/sunxi-ng/ccu-sun9i-a80-de.o drivers/clk/sunxi-ng/ccu-sun9i-a80-usb.o drivers/clk/sunxi-ng/lib.a drivers/clk/sunxi-ng/lib-ksyms.o > >> > > > >> > > This incremental link pulls in all your lib.a objects and links them > >> > > into built-in.o. They can no longer be selectively linked. > >> > > >> > I think the ARM defconfig actually needs all those objects because it > >> > enables all the high-level drivers. You could try disabling e.g. all except > >> > CONFIG_SUN8I_DE2_CCU if you want the objects to actually becomes > >> > unused. > >> > >> You can also disable MACH_SUN8I, it should disable a significant > >> number of the clocks driver. > > > > text data bss dec hex filename > > 11655078 6018736 418944 18092758 11412d6 vmlinux.inclink > > 11655078 6018736 418944 18092758 11412d6 vmlinux.inclink.clk > > 11650534 6010288 418616 18079438 113dece vmlinux.thinarc > > 11650534 6010288 418616 18079438 113dece vmlinux.thinarc.clk > > > > Same result for me when compiling defconfig minus MACH_SUN8I, comparing > > +/- the clock patch and thin archives. No size savings. As I explained > > already, I really can't see how there could be any saving if the lib.a is > > incrementally linked into built-in.o. > > I think defconfig minus MACH_SUN8I > will give no difference to CONFIG_SUNXI_CCU* > > As far as I tried, minus MACH_SUN8I still enabled the following: > CONFIG_SUNXI_CCU=y > CONFIG_SUNXI_CCU_DIV=y > CONFIG_SUNXI_CCU_FRAC=y > CONFIG_SUNXI_CCU_GATE=y > CONFIG_SUNXI_CCU_MUX=y > CONFIG_SUNXI_CCU_MULT=y > CONFIG_SUNXI_CCU_PHASE=y > CONFIG_SUNXI_CCU_NK=y > CONFIG_SUNXI_CCU_NKM=y > CONFIG_SUNXI_CCU_NKMP=y > CONFIG_SUNXI_CCU_NM=y > CONFIG_SUNXI_CCU_MP=y > > I think you need to disable some more MACH_SUN*I and > perhaps disable some CONFIG_SUN*I_*_CCU explicitly, > then you will see difference in the result. Ah, right, it's all selected by the rest. I guess to get a meaningful example you could disable all the SUN*I_CCU (SUN5I, SUN8I, and the likes) options and while keeping SUN8I_R_CCU. Most of the clock types shouldn't be used but div and gates. Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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