From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13275 invoked by alias); 19 Feb 2003 21:20:34 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 13268 invoked from network); 19 Feb 2003 21:20:34 -0000 Received: from unknown (HELO mx1.redhat.com) (172.16.49.200) by 172.16.49.205 with SMTP; 19 Feb 2003 21:20:34 -0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.11.6/8.11.6) with ESMTP id h1JLKYK05613 for ; Wed, 19 Feb 2003 16:20:34 -0500 Received: from pobox.corp.redhat.com (pobox.corp.redhat.com [172.16.52.156]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id h1JLKYa04538 for ; Wed, 19 Feb 2003 16:20:34 -0500 Received: from localhost.redhat.com (romulus-int.sfbay.redhat.com [172.16.27.46]) by pobox.corp.redhat.com (8.11.6/8.11.6) with ESMTP id h1JLKWO14093; Wed, 19 Feb 2003 16:20:33 -0500 Received: by localhost.redhat.com (Postfix, from userid 469) id 944D1FF79; Wed, 19 Feb 2003 16:24:39 -0500 (EST) From: Elena Zannoni MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15955.62999.412522.284136@localhost.redhat.com> Date: Wed, 19 Feb 2003 21:20:00 -0000 To: Daniel Jacobowitz Cc: Elena Zannoni , gdb-patches@sources.redhat.com Subject: Re: RFA: Fix a big memory leak reading minimal symbols In-Reply-To: <20030205222626.GA28452@nevyn.them.org> References: <20030126191411.GA1824@nevyn.them.org> <15937.26495.326748.558348@localhost.redhat.com> <20030205222626.GA28452@nevyn.them.org> X-SW-Source: 2003-02/txt/msg00442.txt.bz2 Daniel Jacobowitz writes: > On Wed, Feb 05, 2003 at 02:35:27PM -0500, Elena Zannoni wrote: > > Daniel Jacobowitz writes: > > > This patch is good for a whopping 13% (7MB) of memory usage when reading in > > > all of mozilla's minimal symbols (stabs). The control flow looks like this > > > right now: > > > - init_minimal_symbol_collection in elf_symfile_read > > > - install_minimal_symbols in elfstab_build_psymtabs. Presumably added so > > > that we don't lose the minimal symbols above. > > > > right, elfstab_build_psymtab is called by elf_symfile_read, after > > init_minimal_symbol_collection. > > > > > - dbx_symfile_read contains a complete init_minimal_symbol_collection / > > > install_minimal_symbols pair, which generally finds no minimal symbols > > > in ELF. > > > > elfstab_build_psymtab calls dbx_symfile_read. > > > > > - install_minimal_symbols and matching cleanup in elf_symfile_read. > > > > > > > at the end. > > > > > Only problem is, that second init_minimal_symbol_collection call zeroed out > > > the bunch pointer. We've installed them but we never free them, so they > > > just sit around wasting memory. > > > > OK, I see the problem in this sequence. There is another 'stray' call > > to install_minimal_symbols, in stabsect_build_psymtab, and this > > function also calls dbx_symfile_read. The sequence is the same. So the > > problem should occur there as well. > > stabsect_build_psymtab is called by som_symfile_read. > > And by nlm_symfile_read too. > > > > This patch arranges for all calls to init_minimal_symbol_collection in ELF > > > targets to be paired with matching cleanups and install_minimal_symbols > > > calls. This means that elfmdebug_build_psymtabs gets its own pair instead > > > of relying on elf_symfile_read, and that elf_symfile_read installs its own > > > minimal symbols much earlier. > > > > How does elfstab_build_psymtabs get invoked from mdebug? Oh, it > > doesn't. It gets invoked after the mdebug stuff is over. > > > > I see, you are adding pairs of install+cleanup to the mdebug psymtab > > builder, i.e. each piece is self-sufficient. For the stabs psymtab > > builder the appropriate steps are done in dbx_symfile_read already. > > Right. Each reader that wants to do this, should do it itself, since > they don't nest. > > > let's see all the symtabs builders: > > > > coffstab_build_psymtabs -> calls dbx_symfile_read ok > > Ugh. This is OK but its caller isn't; coff_symtab_read has some > minimal symbols outstanding when it calls coffstab_build_psymtabs. > Fixed, but I don't have any tests for COFF set up. > > > elfstab_build_psymtabs -> you fixed ok > > stabsect_build_psymtabs -> dubious > > Fixed, in both callers. > > > dwarf2_build_psymtabs -> no need > > dwarf_build_psymtabs -> don't care > > hpread_build_psymtabs -> no clue, messy. I think it does it directly. > > mdebug_build_psymtabs -> you fixed ok > > > > if the table above makes sense, then can you verify/fix the dubious case? > > How's this look? New changes in coff_symfile_read, nlm_symfile_read, > som_symfile_read, and stabsect_build_psymtabs. > Okey elena > -- > Daniel Jacobowitz > MontaVista Software Debian GNU/Linux Developer > > 2002-02-05 Daniel Jacobowitz > > * coffread.c (coff_symfile_read): Clean up minimal symbols earlier. > * dbxread.c (elfstab_build_psymtabs): Don't call > install_minimal_symbols. > (stabsect_build_psymtabs): Likewise. > * elfread.c (elf_symfile_read): Call install_minimal_symbols > earlier. > * somread.c (som_symfile_read): Call install_minimal_symbols > and do_cleanups earlier. > * nlmread.c (nlm_symfile_read): Likewise. > * mdebugread.c (elfmdebug_build_psymtabs): Call > install_minimal_symbols and make appropriate cleanups. > > Index: coffread.c > =================================================================== > RCS file: /cvs/src/src/gdb/coffread.c,v > retrieving revision 1.33 > diff -u -p -r1.33 coffread.c > --- coffread.c 4 Feb 2003 18:07:00 -0000 1.33 > +++ coffread.c 5 Feb 2003 22:22:13 -0000 > @@ -515,7 +515,7 @@ coff_symfile_read (struct objfile *objfi > unsigned int num_symbols; > int symtab_offset; > int stringtab_offset; > - struct cleanup *back_to; > + struct cleanup *back_to, *cleanup_minimal_symbols; > int stabstrsize; > int len; > char * target; > @@ -595,7 +595,7 @@ coff_symfile_read (struct objfile *objfi > error ("\"%s\": can't get string table", name); > > init_minimal_symbol_collection (); > - make_cleanup_discard_minimal_symbols (); > + cleanup_minimal_symbols = make_cleanup_discard_minimal_symbols (); > > /* Now that the executable file is positioned at symbol table, > process it and define symbols accordingly. */ > @@ -615,6 +615,9 @@ coff_symfile_read (struct objfile *objfi > minimal symbols for this objfile. */ > > install_minimal_symbols (objfile); > + > + /* Free the installed minimal symbol data. */ > + do_cleanups (cleanup_minimal_symbols); > > bfd_map_over_sections (abfd, coff_locate_sections, (void *) info); > > Index: dbxread.c > =================================================================== > RCS file: /cvs/src/src/gdb/dbxread.c,v > retrieving revision 1.41 > diff -u -p -r1.41 dbxread.c > --- dbxread.c 31 Jan 2003 19:22:17 -0000 1.41 > +++ dbxread.c 5 Feb 2003 22:22:13 -0000 > @@ -3555,7 +3555,6 @@ elfstab_build_psymtabs (struct objfile * > buildsym_new_init (); > free_header_files (); > init_header_files (); > - install_minimal_symbols (objfile); > > processing_acc_compilation = 1; > > @@ -3567,7 +3566,10 @@ elfstab_build_psymtabs (struct objfile * > > /* In an elf file, we've already installed the minimal symbols that came > from the elf (non-stab) symbol table, so always act like an > - incremental load here. */ > + incremental load here. dbx_symfile_read should not generate any new > + minimal symbols, since we will have already read the ELF dynamic symbol > + table and normal symbol entries won't be in the ".stab" section; but in > + case it does, it will install them itself. */ > dbx_symfile_read (objfile, 0); > > if (back_to) > @@ -3649,7 +3651,6 @@ stabsect_build_psymtabs (struct objfile > buildsym_new_init (); > free_header_files (); > init_header_files (); > - install_minimal_symbols (objfile); > > /* Now, do an incremental load */ > > Index: elfread.c > =================================================================== > RCS file: /cvs/src/src/gdb/elfread.c,v > retrieving revision 1.30 > diff -u -p -r1.30 elfread.c > --- elfread.c 31 Jan 2003 19:22:18 -0000 1.30 > +++ elfread.c 5 Feb 2003 22:22:14 -0000 > @@ -542,6 +542,15 @@ elf_symfile_read (struct objfile *objfil > > elf_symtab_read (objfile, 1); > > + /* Install any minimal symbols that have been collected as the current > + minimal symbols for this objfile. The debug readers below this point > + should not generate new minimal symbols; if they do it's their > + responsibility to install them. "mdebug" appears to be the only one > + which will do this. */ > + > + install_minimal_symbols (objfile); > + do_cleanups (back_to); > + > /* Now process debugging information, which is contained in > special ELF sections. */ > > @@ -611,13 +620,6 @@ elf_symfile_read (struct objfile *objfil > > if (DWARF2_BUILD_FRAME_INFO_P ()) > DWARF2_BUILD_FRAME_INFO(objfile); > - > - /* Install any minimal symbols that have been collected as the current > - minimal symbols for this objfile. */ > - > - install_minimal_symbols (objfile); > - > - do_cleanups (back_to); > } > > /* This cleans up the objfile's sym_stab_info pointer, and the chain of > Index: mdebugread.c > =================================================================== > RCS file: /cvs/src/src/gdb/mdebugread.c,v > retrieving revision 1.40 > diff -u -p -r1.40 mdebugread.c > --- mdebugread.c 4 Feb 2003 18:07:01 -0000 1.40 > +++ mdebugread.c 5 Feb 2003 22:22:15 -0000 > @@ -4808,6 +4808,14 @@ elfmdebug_build_psymtabs (struct objfile > { > bfd *abfd = objfile->obfd; > struct ecoff_debug_info *info; > + struct cleanup *back_to; > + > + /* FIXME: It's not clear whether we should be getting minimal symbol > + information from .mdebug in an ELF file, or whether we will. > + Re-initialize the minimal symbol reader in case we do. */ > + > + init_minimal_symbol_collection (); > + back_to = make_cleanup_discard_minimal_symbols (); > > info = ((struct ecoff_debug_info *) > obstack_alloc (&objfile->psymbol_obstack, > @@ -4818,6 +4826,9 @@ elfmdebug_build_psymtabs (struct objfile > bfd_errmsg (bfd_get_error ())); > > mdebug_build_psymtabs (objfile, swap, info); > + > + install_minimal_symbols (objfile); > + do_cleanups (back_to); > } > > > Index: nlmread.c > =================================================================== > RCS file: /cvs/src/src/gdb/nlmread.c,v > retrieving revision 1.9 > diff -u -p -r1.9 nlmread.c > --- nlmread.c 2 Dec 2001 22:38:23 -0000 1.9 > +++ nlmread.c 5 Feb 2003 22:22:15 -0000 > @@ -190,6 +190,12 @@ nlm_symfile_read (struct objfile *objfil > > nlm_symtab_read (abfd, offset, objfile); > > + /* Install any minimal symbols that have been collected as the current > + minimal symbols for this objfile. */ > + > + install_minimal_symbols (objfile); > + do_cleanups (back_to); > + > stabsect_build_psymtabs (objfile, mainline, ".stab", > ".stabstr", ".text"); > > @@ -204,13 +210,6 @@ nlm_symfile_read (struct objfile *objfil > > /* FIXME: We could locate and read the optional native debugging format > here and add the symbols to the minimal symbol table. */ > - > - /* Install any minimal symbols that have been collected as the current > - minimal symbols for this objfile. */ > - > - install_minimal_symbols (objfile); > - > - do_cleanups (back_to); > } > > > Index: somread.c > =================================================================== > RCS file: /cvs/src/src/gdb/somread.c,v > retrieving revision 1.16 > diff -u -p -r1.16 somread.c > --- somread.c 19 Jan 2003 04:06:46 -0000 1.16 > +++ somread.c 5 Feb 2003 22:22:15 -0000 > @@ -353,6 +353,14 @@ som_symfile_read (struct objfile *objfil > > som_symtab_read (abfd, objfile, objfile->section_offsets); > > + /* Install any minimal symbols that have been collected as the current > + minimal symbols for this objfile. > + Further symbol-reading is done incrementally, file-by-file, > + in a step known as "psymtab-to-symtab" expansion. hp-symtab-read.c > + contains the code to do the actual DNTT scanning and symtab building. */ > + install_minimal_symbols (objfile); > + do_cleanups (back_to); > + > /* Now read information from the stabs debug sections. > This is a no-op for SOM. > Perhaps it is intended for some kind of mixed STABS/SOM > @@ -366,16 +374,8 @@ som_symfile_read (struct objfile *objfil > together with a scan of the GNTT. See hp-psymtab-read.c. */ > hpread_build_psymtabs (objfile, mainline); > > - /* Install any minimal symbols that have been collected as the current > - minimal symbols for this objfile. > - Further symbol-reading is done incrementally, file-by-file, > - in a step known as "psymtab-to-symtab" expansion. hp-symtab-read.c > - contains the code to do the actual DNTT scanning and symtab building. */ > - install_minimal_symbols (objfile); > - > /* Force hppa-tdep.c to re-read the unwind descriptors. */ > objfile->obj_private = NULL; > - do_cleanups (back_to); > } > > /* Initialize anything that needs initializing when a completely new symbol