Messages in this thread | | | Date | Tue, 7 Dec 2021 07:30:59 +0100 (CET) | From | Julia Lawall <> | Subject | Re: [PATCH] sysctl: Add a group of macro functions to initcall the sysctl table of each feature |
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On Mon, 6 Dec 2021, Joe Perches wrote:
> On Mon, 2021-12-06 at 17:38 -0800, Andrew Morton wrote: > > On Tue, 7 Dec 2021 09:13:20 +0800 Xiaoming Ni <nixiaoming@huawei.com> wrote: > > > > > To avoid duplicated code, add a set of macro functions to initialize the > > > sysctl table for each feature. > > > > > > The system initialization process is as follows: > > > > > > start_kernel () { > > > ... > > > /* init proc and sysctl base, > > > * proc_root_init()-->proc_sys_init()-->sysctl_init_bases() > > > */ > > > proc_root_init(); /* init proc and sysctl base */ > > > ... > > > arch_call_rest_init(); > > > } > > > > > > arch_call_rest_init()-->rest_init()-->kernel_init() > > > kernel_init() { > > > ... > > > kernel_init_freeable(); /* do all initcalls */ > > > ... > > > do_sysctl_args(); /* Process the sysctl parameter: sysctl.*= */ > > > } > > > > > > kernel_init_freeable()--->do_basic_setup()-->do_initcalls() > > > do_initcalls() { > > > for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { > > > do_initcall_level > > > } > > > > > > The sysctl interface of each subfeature should be registered after > > > sysctl_init_bases() and before do_sysctl_args(). It seems that the sysctl > > > interface does not depend on initcall_levels. To prevent the sysctl > > > interface from being initialized before the feature itself. The > > > lowest-level late_initcall() is used as the common sysctl interface > > > registration level. > > > > I'm not normally a fan of wrapping commonly-used code sequences into > > magical macros, but this one does seem to make sense. > > > > I wonder if it is possible to cook up a checkpatch rule to tell people > > to henceforth use the magic macros rather than to open-code things in > > the old way. Sounds hard. > > Almost impossible for checkpatch. > Likely easier in coccinelle.
Is there a typical example of the open coded version?
julia
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