-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Hi there people,
i only need a confirmation on some unclear issues concerning the following
function:
<include/linux/slab.h>
77 static inline void *kmalloc(size_t size, int flags)
78 {
79 if (__builtin_constant_p(size)) {
80 int i = 0;
81 #define CACHE(x) \
82 if (size <= x) \
83 goto found; \
84 else \
85 i++;
86 #include "kmalloc_sizes.h"
87 #undef CACHE
88 {
89 extern void __you_cannot_kmalloc_that_much(void);
90 __you_cannot_kmalloc_that_much();
91 }
92 found:
93 return kmem_cache_alloc((flags & GFP_DMA) ?
94 malloc_sizes[i].cs_dmacachep :
95 malloc_sizes[i].cs_cachep, flags);
96 }
97 return __kmalloc(size, flags);
98 }
I understand that the CACHE macro is used to search the malloc_sizes array to
find a slab object that is (size <= x) and if it is found, we jump to the
found label where we call kmem_cache_alloc(). After we #undef CACHE, we have
a block with that external function that is declared nowhere. After googling
a while, I think I know what this does but i'm not sure - when, at compile
time, something requests a slab object that is bigger than the alloc'd ones,
we break compilation and force the caller to change its call to kmalloc in
order to request a more suitable size object. I don't understand the thoughts
behind that, though, thus my question.
Thanks in advance for your help,
Boris.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.5 (GNU/Linux)
iD8DBQFBDf64iBySr3Fn37QRAsreAJ4nAZof1ixOM3ZDo2ADIMjgXrYCzACfXBVc
VMqT17YfOFPlmPyEXOLjxic=
=i6PV
-----END PGP SIGNATURE-----
--
Kernelnewbies: Help each other learn about the Linux kernel.
Archive: http://mail.nl.linux.org/kernelnewbies/
FAQ: http://kernelnewbies.org/faq/
