On Sat, 03 Oct 2026 11:27:10 -0500 Lawrence Lin via B4 Relay <[email protected]> wrote:
> From: Lawrence Lin <[email protected]> > > Since commit b39181f7c690 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid > adding weak function"), ftrace_module_enable() calls test_for_valid_rec() > for every ftrace record of a module being loaded. test_for_valid_rec() > resolves the record address with kallsyms_lookup(), and for a module > address find_kallsyms_symbol() scans the whole symbol table of the module. > Loading a module therefore costs O(records * symbols), all of it under > ftrace_lock. Honestly, I think we can revert commit b39181f7c690. Since commit ef378c3b823385 ("scripts/sorttable: Zero out weak functions in mcount_loc table"), I believe that commit has become obsolete. I just kept it because I didn't want to add regressions. It would be interesting if it actually triggers (finds something). If it doesn't, then I think we should just remove that code instead of adding more complexity to it. -- Steve
