From 89ba308506249736c6d0c8490d3c897af4e42df8 Mon Sep 17 00:00:00 2001 From: "Frank Ch. Eigler" Date: Tue, 8 Sep 2009 20:23:42 -0400 Subject: PR10524: reduce massive-uprobe script modules' .data consumption The general approach is to rip out task_finder_tgt's from all over the place (including the unwindsym vmcbs, and the stap_uprobe_specs), and instead have a small handful of them: one for all unwindsyms, and one per abstract probed process (PID or NAME). These are in turn shared by all new stap_unwind_specs by index. Before: probe process("./stap").function("*") -rw-r--r--. 1 fche users 11775283 2009-09-08 20:26 /var/tmp/fche/systemtap/cache/96/stap_96c0479d674db55ec98d8a8750a790e7_7989596.ko text data bss dec hex filename 445158 8351944 4306472 13103574 c7f1d6 /var/tmp/fche/systemtap/cache/96/stap_96c0479d674db55ec98d8a8750a790e7_7989596.ko After: (Note how data shrank, though text gained a bit in const-init-data.) -rw-r--r--. 1 fche users 4021569 2009-09-08 20:27 /var/tmp/fche/systemtap/cache/e4/stap_e46e88634efd850b1586e81c231c239a_8058419.ko text data bss dec hex filename 1896511 2192 4324808 6223511 5ef697 /var/tmp/fche/systemtap/cache/e4/stap_e46e88634efd850b1586e81c231c239a_8058419.ko * tapsets.cxx (uprobe_derived_probe_group): Rewrite emit_module_decls, and adjust emit_module_init. * runtime/sym.c (_stp_sym_init): Initialize unwindsyms-shared vmcb. * runtime/sym.h (_stp_module): Remove *vmcb field. * translate.cxx (emit_module_init, dump_unwindsyms): Adapt. * translate.h (assert_0_indent): Flush output before possibly assert-failing. --- runtime/sym.c | 55 ++++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 40 insertions(+), 15 deletions(-) (limited to 'runtime/sym.c') diff --git a/runtime/sym.c b/runtime/sym.c index 856ccbcc..0baa1a5e 100644 --- a/runtime/sym.c +++ b/runtime/sym.c @@ -16,21 +16,6 @@ #include "string.c" #include "task_finder_vma.c" -/** @file sym.c - * @addtogroup sym Symbolic Functions - * Symbolic Lookup Functions - * @{ - */ - -static void _stp_sym_init(void) -{ - static int initialized = 0; - if (! initialized) { - __stp_tf_vma_initialize(); - initialized = 1; - } -} - /* Callback that needs to be registered (in session.unwindsyms_modules) for every user task path for which we might need symbols or unwind info. */ @@ -409,4 +394,44 @@ static void _stp_symbol_snprint(char *str, size_t len, unsigned long address, } /** @} */ + + +/** @file sym.c + * @addtogroup sym Symbolic Functions + * Symbolic Lookup Functions + * @{ + */ +static void _stp_sym_init(void) +{ + // NB: it's too "early" to make this conditional on STP_NEED_VMA_TRACKER, + // since we're #included at the top of the generated module, before any + // tapset-induced #define's. +#if defined(CONFIG_UTRACE) + static int initialized = 0; + static struct stap_task_finder_target vmcb = { + // NB: no .pid, no .procname filters here. + // This means that we get a system-wide mmap monitoring + // widget while the script is running. (The system-wideness may + // be restricted by stap -c or -x.) But this seems to + // be necessary if we want to to stack tracebacks through arbitrary + // shared libraries. XXX: There may be an optimization opportunity + // for executables (for which the main task-finder callback should be + // sufficient). + .mmap_callback = &_stp_tf_mmap_cb, + .munmap_callback = &_stp_tf_munmap_cb, + }; + if (! initialized) { + int rc; + __stp_tf_vma_initialize(); + rc = stap_register_task_finder_target (& vmcb); +#ifdef DEBUG_TASK_FINDER_VMA + _stp_dbug(__FUNCTION__, __LINE__, "registered vmcb"); +#endif + (void) rc; // XXX + initialized = 1; + } +#endif +} + + #endif /* _STP_SYM_C_ */ -- cgit