Em Tue, Mar 30, 2021 at 08:20:20PM -0700, Yonghong Song escreveu: > On 3/30/21 11:24 AM, Arnaldo Carvalho de Melo wrote: > > Em Tue, Mar 30, 2021 at 03:08:06PM -0300, Arnaldo Carvalho de Melo escreveu: > > > [acme@five pahole]$ fullcircle tcp_bbr.o > > > [acme@five pahole]$ > > > This one is dealt with, doing some more tests and looking at that > > > array[] versus array[0]. > > I've pushed what I have to the main repos at kernel.org and github, > > please check, I'll continue from there. > Looks good. Thanks! > I will try to experiment with an alternative way ([1]) to check whether > cross-cu reference happens or not. But at least checking flags > approach can be adapted to gcc (if we want after comparing the alternative) > since gcc always has flags in dwarf. > [1] https://lore.kernel.org/bpf/d34a3d62-bae8-3a30-26b6-4e5e8efcd0af@xxxxxx/T/#m1b0b1206091c19a90b15d054aa26239101289f84 I thought about some other method, like adding a ELF note to vmlinux stating that this was built with LTO, that would be the fastest way, I think. If that note wasn't there, then we would fallback to looking at inter CU references, that way we would have the best of both worlds and wouldn't incur in per-CU DW_AT_producer overheads with the flags for each object file. - Arnaldo
