Messages in this thread | | | Date | Tue, 16 Jan 2018 12:07:49 -0600 (CST) | From | Christopher Lameter <> | Subject | Re: kmem_cache_attr (was Re: [PATCH 04/36] usercopy: Prepare for usercopy whitelisting) |
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On Tue, 16 Jan 2018, Matthew Wilcox wrote:
> > Sure this data is never changed. It can be const. > > It's changed at initialisation. Look: > > kmem_cache_create(const char *name, size_t size, size_t align, > slab_flags_t flags, void (*ctor)(void *)) > s = create_cache(cache_name, size, size, > calculate_alignment(flags, align, size), > flags, ctor, NULL, NULL); > > The 'align' that ends up in s->align, is not the user-specified align. > It's also dependent on runtime information (cache_line_size()), so it > can't be calculated at compile time.
Then we would need another align field in struct kmem_cache that takes the changes value?
> 'flags' also gets mangled: > flags &= CACHE_CREATE_MASK;
Well ok then that also belongs into kmem_cache and the original value stays in kmem_cache_attr.
> unsigned int would be my preference.
Great.
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