Hi All,
On 3.4-rc49, I got following failure running `perf test`:
/ # perf test -v 1
1: vmlinux symtab matches kallsyms:
--- start ---
dso__find_symbol_by_name ---- end ----
vmlinux symtab matches kallsyms: FAILED!
Perf test is failing at dsofind_symbol_by_name
where
kallsyms_map = machine__kernel_map(&kallsyms, type);
sym = map__find_symbol_by_name(kallsyms_map, ref_reloc_sym.name, NULL);
if (sym == NULL) {
pr_debug("dso__find_symbol_by_name ");
goto out;
}
Here sym is search for "_stext" which is NULL here so perf test fails
here only.
On investigation found that _stext having same address as asm_do_IRQ
and exception_text_start,
c00081c0 T asm_do_IRQ
c00081c0 T _stext
c00081c0 T __exception_text_start
so being deleted by symbolsfixup_duplicate in
if (choose_best_symbol(curr, next) == SYMBOL_A) {
rb_erase(&next->rb_node, symbols); --> symbole
getting erase here.
goto again;
} else {
My doubt is, Is we really need this commit??:
commit 3f5a42722b9e78a434d5a4ee5e607dc33c69ac80
Author: Anton Blanchard <an...@samba.org>
Date: Wed Aug 24 16:40:15 2011 +1000
perf symbols: /proc/kallsyms does not sort module symbols
kallsyms__parse assumes that /proc/kallsyms is sorted and sets the end
of the previous symbol to the start of the current one.
Unfortunately module symbols are not sorted, eg:
ffffffffa0081f30 t e1000_clean_rx_irq [e1000e]
ffffffffa00817a0 t e1000_alloc_rx_buffers [e1000e]
Some symbols end up with a negative length and others have a length
larger than they should. This results in confusing perf output.
We already have a function to fixup the end of zero length symbols so
use that instead.
Or we can search or other string.??
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
