Having many dozens of modules, the searches down the linked
list of sections would dominate the lookup time, dwarfing
any savings from the binary search within the section.
A simple move-to-front optimisation exploits the commonality
of the code paths taken, and in simple real-world tests
on other architectures reduced the number of steps in the
search to barely more than 1.
Signed-off-by: Phil Carmody <ext-phil.2.carmody@xxxxxxxxx>
---
arch/parisc/kernel/unwind.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/arch/parisc/kernel/unwind.c b/arch/parisc/kernel/unwind.c
index d58eac1..76ed62e 100644
--- a/arch/parisc/kernel/unwind.c
+++ b/arch/parisc/kernel/unwind.c
@@ -80,8 +80,11 @@ find_unwind_entry(unsigned long addr)
if (addr >= table->start &&
addr <= table->end)
e = find_unwind_entry_in_table(table, addr);
- if (e)
+ if (e) {
+ /* Move-to-front to exploit common traces */
+ list_move(&table->list, &unwind_tables);
break;
+ }
}
return e;
--
1.5.6.5
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