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    SubjectRe: [PATCH 1/7] cgroups: Shrink struct cgroup_subsys
    On Tue, Nov 9, 2010 at 4:52 PM, Li Zefan <lizf@cn.fujitsu.com> wrote:
    >>
    >> bool active:1;
    >> bool disabled:1;
    >>
    >
    > It won't compile, but unsigned char active:1 will do. ;)

    Are you sure? I don't have a buildable kernel tree at the moment, but
    the following fragment compiled fine for me (with gcc 4.4.3):

    struct foo {
    _Bool b1:1;
    _Bool b2:1;
    };

    and was sized at one byte. And "bool" is just a typedef of _Bool in
    the kernel headers.

    >
    > Every thing that reduces code size (without sacrifice readability
    > and maintain maintainability) should be worth.

    Agreed, within reason. But this patch doesn't reduce code size - it
    makes the code fractionally more complicated and reduces the *binary*
    size by a few bytes.

    >
    > This is one of the reasons we accept patches that replacing
    > kmalloc+memset with kzalloc, which just saves 8 bytes in my box.
    >

    Replacing two function calls with one function call is a code
    simplification and hence (generally) a good thing - the minuscule
    reduction in binary size reduction that comes with it is just noise.

    Paul


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