Recently, in my arch (SuperH which uses two-level page table), I've
changed the function pgd_clear to zero-clear the entry. Then, we see
memory leak.
I think that pgd_clear in free_one_pgd should be placed _after_
calling free_one_pmd. Or else, free_one_pmd doesn't free anything.
This memory leak occurs when the architecture uses two-level page table
and non-null implementation of pgd_clear.
Index: mm/memory.c
===================================================================
RCS file: /cvsroot/linuxsh/kernel/mm/memory.c,v
retrieving revision 1.31
diff -u -p -r1.31 memory.c
--- mm/memory.c 2001/07/11 01:12:27 1.31
+++ mm/memory.c 2001/07/16 08:05:46
@@ -102,9 +102,9 @@ static inline void free_one_pgd(pgd_t *
return;
}
pmd = pmd_offset(dir, 0);
- pgd_clear(dir);
for (j = 0; j < PTRS_PER_PMD ; j++)
free_one_pmd(pmd+j);
+ pgd_clear(dir);
pmd_free(pmd);
}
--