Messages in this thread | | | Date | Wed, 10 Nov 2010 08:52:34 +0800 | From | Li Zefan <> | Subject | Re: [PATCH 1/7] cgroups: Shrink struct cgroup_subsys |
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Paul Menage wrote: > On Sun, Nov 7, 2010 at 9:23 PM, Li Zefan <lizf@cn.fujitsu.com> wrote: >> bool active; >> bool disabled; >> ... >> >> ? >> >> With alignment 5-8 bool values == 8 bytes in 64-bit machine, compared to >> 4 bytes with the approach this patch takes. > > I meant specifying it as: > > bool active:1; > bool disabled:1; >
It won't compile, but unsigned char active:1 will do. ;)
> i.e. keeping the bit-sized flags but also keeping the bool semantics. > Having said that, I'm not really sure why saving 12 bytes per > subsystem is worth a patch.
Every thing that reduces code size (without sacrifice readability and maintain maintainability) should be worth.
This is one of the reasons we accept patches that replacing kmalloc+memset with kzalloc, which just saves 8 bytes in my box.
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