The patch titled
fork_init: fix division by zero
has been added to the -mm tree. Its filename is
fork_init-fix-division-by-zero.patch
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------------------------------------------------------
Subject: fork_init: fix division by zero
From: Yuri Tikhonov <yur@xxxxxxxxxxx>
Fix a divide-by-zero error for the cases of really big PAGE_SIZEs (e.g.
256KB on ppc44x). Support for big page sizes on 44x is not present in the
current kernel yet, but coming soon.
Also this patch fixes the comment for the max_threads settings, as this
didn't match the things actually done in the code.
Signed-off-by: Yuri Tikhonov <yur@xxxxxxxxxxx>
Signed-off-by: Ilya Yanok <yanok@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/fork.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff -puN kernel/fork.c~fork_init-fix-division-by-zero kernel/fork.c
--- a/kernel/fork.c~fork_init-fix-division-by-zero
+++ a/kernel/fork.c
@@ -69,6 +69,7 @@
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
+#include <asm/div64.h>
/*
* Protected counters by write_lock_irq(&tasklist_lock)
@@ -185,10 +186,15 @@ void __init fork_init(unsigned long memp
/*
* The default maximum number of threads is set to a safe
- * value: the thread structures can take up at most half
- * of memory.
+ * value: the thread structures can take up at most
+ * (1/8) part of memory.
*/
- max_threads = mempages / (8 * THREAD_SIZE / PAGE_SIZE);
+ {
+ /* max_threads = (mempages * PAGE_SIZE) / THREAD_SIZE / 8; */
+ u64 m = mempages * PAGE_SIZE;
+ do_div(m, THREAD_SIZE * 8);
+ max_threads = m;
+ }
/*
* we need to allow at least 20 threads to boot a system
_
Patches currently in -mm which might be from yur@xxxxxxxxxxx are
linux-next.patch
fork_init-fix-division-by-zero.patch
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