Messages in this thread | | | Date | Fri, 11 Oct 2013 14:01:43 +0000 | From | Christoph Lameter <> | Subject | Re: [PATCH 34/34] mm: dynamically allocate page->ptl if it cannot be embedded to struct page |
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On Thu, 10 Oct 2013, Kirill A. Shutemov wrote:
> Christoph Lameter wrote: > > On Thu, 10 Oct 2013, Kirill A. Shutemov wrote: > > > > > +static inline bool ptlock_alloc(struct page *page) > > > +{ > > > + if (sizeof(spinlock_t) > sizeof(page->ptl)) > > > + return __ptlock_alloc(page); > > > + return true; > > > +} > > > > Could you make the check a CONFIG option? CONFIG_PTLOCK_DOES_NOT_FIT_IN_PAGE_STRUCT or > > so? > > No. We will have to track what affects sizeof(spinlock_t) manually. > Not a fun and error prune.
You can generate a config option depending on the size of the object via Kbuild. Kbuild will determine the setting before building the kernel as a whole by runing some small C program.
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