[PATCH 1/2] Add thread_info_cache_init() to all archs

From: Benjamin Herrenschmidt
Date: Thu Apr 10 2008 - 19:40:01 EST


Some architecture need to maintain a kmem cache for thread info
structures. (next patch adds that to powerpc to fix an alignment
problem).

There is no good arch callback to use to initialize that cache
that I can find, so this adds a new one and adds an empty macro
for when it's not implemented.

Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
---

So we have the choice here between:

- the ifdef on the func name that I did, consistent with what
I did before for iomap, which iirc Linus liked

- add some more ARCH_HAS_* or HAVE_* (yuck)

- add an empty definition to all archs .h (pain in the neck but I
can do it, though it will be an annoying patch to keep around)

- do a weak function (will slightly bloat everybody for no good reason)

So unless there is strong complaints, I'd like to stick to my
current approach.

(This one fixes a stupid typo, missing () in the macro def.)

include/linux/sched.h | 4 ++++
init/main.c | 1 +
2 files changed, 5 insertions(+)

--- linux-work.orig/init/main.c 2008-04-10 13:11:06.000000000 +1000
+++ linux-work/init/main.c 2008-04-10 13:11:19.000000000 +1000
@@ -623,6 +623,7 @@ asmlinkage void __init start_kernel(void
if (efi_enabled)
efi_enter_virtual_mode();
#endif
+ thread_info_cache_init();
fork_init(num_physpages);
proc_caches_init();
buffer_init();
Index: linux-work/include/linux/sched.h
===================================================================
--- linux-work.orig/include/linux/sched.h 2008-04-10 13:11:44.000000000 +1000
+++ linux-work/include/linux/sched.h 2008-04-11 09:35:58.000000000 +1000
@@ -1893,6 +1893,10 @@ static inline unsigned long *end_of_stac

#endif

+#ifndef thread_info_cache_init
+#define thread_info_cache_init() do { } while(0)
+#endif
+
/* set thread flags in other task's structures
* - see asm/thread_info.h for TIF_xxxx flags available
*/
--
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