Re: [PATCH] hugetlb_cgroup: explicitly init the early_init field
On 2014/4/22 15:01, Jianyu Zhan wrote: > Hi, hillf, > > On Tue, Apr 22, 2014 at 2:47 PM, Hillf Danton wrote: >> But other fields still missed, if any. Fair? > > yep, it is not fair. > > Sure for this global variable struct, if not initailized, its all > fields will be initialized > to 0 or null(depending on its type). The point here is no to deprive > the rights of > compiler/linker of doing this initialization, it is mainly for > documentation reason. > Actually this field's value would affect how ->css_alloc should implemented. > > Concretely, if early_init is nonzero, then ->css_alloc *must not* call > kzalloc, > because in cgroup implementation, ->css_alloc will be called earlier before > mm_init(). > > I don't think that the value of one field(early_init) has a so subtle > restrition on the > another field(css_alloc) is a good thing, but since it is there, > docment it should > be needed. > I don't see how things can be improved by initializing it to 0 explicitly, if anything needs to be improved. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] hugetlb_cgroup: explicitly init the early_init field
Hi, hillf, On Tue, Apr 22, 2014 at 2:47 PM, Hillf Danton wrote: > But other fields still missed, if any. Fair? yep, it is not fair. Sure for this global variable struct, if not initailized, its all fields will be initialized to 0 or null(depending on its type). The point here is no to deprive the rights of compiler/linker of doing this initialization, it is mainly for documentation reason. Actually this field's value would affect how ->css_alloc should implemented. Concretely, if early_init is nonzero, then ->css_alloc *must not* call kzalloc, because in cgroup implementation, ->css_alloc will be called earlier before mm_init(). I don't think that the value of one field(early_init) has a so subtle restrition on the another field(css_alloc) is a good thing, but since it is there, docment it should be needed. Thanks, Jianyu Zhan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] hugetlb_cgroup: explicitly init the early_init field
On Tue, Apr 22, 2014 at 1:30 PM, Jianyu Zhan wrote:
> For a cgroup subsystem who should init early, then it should carefully
> take care of the implementation of css_alloc, because it will be called
> before mm_init() setup the world.
>
> Luckily we don't, and we better explicitly assign the early_init field
> to 0, for document reason.
>
But other fields still missed, if any. Fair?
> Signed-off-by: Jianyu Zhan
> ---
> mm/hugetlb_cgroup.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
> index 595d7fd..b5368f8 100644
> --- a/mm/hugetlb_cgroup.c
> +++ b/mm/hugetlb_cgroup.c
> @@ -405,4 +405,5 @@ struct cgroup_subsys hugetlb_cgrp_subsys = {
> .css_alloc = hugetlb_cgroup_css_alloc,
> .css_offline= hugetlb_cgroup_css_offline,
> .css_free = hugetlb_cgroup_css_free,
> + .early_init = 0,
> };
> --
> 2.0.0-rc0
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
>
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Re: [PATCH] hugetlb_cgroup: explicitly init the early_init field
On Tue, Apr 22, 2014 at 1:30 PM, Jianyu Zhan nasa4...@gmail.com wrote:
For a cgroup subsystem who should init early, then it should carefully
take care of the implementation of css_alloc, because it will be called
before mm_init() setup the world.
Luckily we don't, and we better explicitly assign the early_init field
to 0, for document reason.
But other fields still missed, if any. Fair?
Signed-off-by: Jianyu Zhan nasa4...@gmail.com
---
mm/hugetlb_cgroup.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index 595d7fd..b5368f8 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -405,4 +405,5 @@ struct cgroup_subsys hugetlb_cgrp_subsys = {
.css_alloc = hugetlb_cgroup_css_alloc,
.css_offline= hugetlb_cgroup_css_offline,
.css_free = hugetlb_cgroup_css_free,
+ .early_init = 0,
};
--
2.0.0-rc0
--
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Re: [PATCH] hugetlb_cgroup: explicitly init the early_init field
Hi, hillf, On Tue, Apr 22, 2014 at 2:47 PM, Hillf Danton dhi...@gmail.com wrote: But other fields still missed, if any. Fair? yep, it is not fair. Sure for this global variable struct, if not initailized, its all fields will be initialized to 0 or null(depending on its type). The point here is no to deprive the rights of compiler/linker of doing this initialization, it is mainly for documentation reason. Actually this field's value would affect how -css_alloc should implemented. Concretely, if early_init is nonzero, then -css_alloc *must not* call kzalloc, because in cgroup implementation, -css_alloc will be called earlier before mm_init(). I don't think that the value of one field(early_init) has a so subtle restrition on the another field(css_alloc) is a good thing, but since it is there, docment it should be needed. Thanks, Jianyu Zhan -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] hugetlb_cgroup: explicitly init the early_init field
On 2014/4/22 15:01, Jianyu Zhan wrote: Hi, hillf, On Tue, Apr 22, 2014 at 2:47 PM, Hillf Danton dhi...@gmail.com wrote: But other fields still missed, if any. Fair? yep, it is not fair. Sure for this global variable struct, if not initailized, its all fields will be initialized to 0 or null(depending on its type). The point here is no to deprive the rights of compiler/linker of doing this initialization, it is mainly for documentation reason. Actually this field's value would affect how -css_alloc should implemented. Concretely, if early_init is nonzero, then -css_alloc *must not* call kzalloc, because in cgroup implementation, -css_alloc will be called earlier before mm_init(). I don't think that the value of one field(early_init) has a so subtle restrition on the another field(css_alloc) is a good thing, but since it is there, docment it should be needed. I don't see how things can be improved by initializing it to 0 explicitly, if anything needs to be improved. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
