On Tue, 5 Nov 2019, Jan Hubicka wrote: > > On Tue, 5 Nov 2019, Jan Hubicka wrote: > > > > > Hi, > > > looking into malloc overhead I noticed that we do a lot of small > > > allocations to hold file names comming from location info. This patch > > > puts it into an obstack so it interleaves memory allocated by scc_hash > > > less frequently. > > > (Still we end up interleaving 64k pages which are permanent - in fact > > > this table seems to leak from WPA and temporary during stream in) > > > > > > Bootstrapped/regtested x86_64-linux. OK? > > > > I think the obstack deserves a big fat comment that it cannot be > > reclaimed since the linemap retains permanent pointers into it. > > That also suggests to put the string_slot into a separate obstack > > The hasher is sort of ethernal, too, since at any time we want to be > able to load more from input streams, so we can not really free it. > Well, I guess just prior streaming we can, so I will split it. > > or better, make the hasher (and other string_slot hashers) > > embed the string_slot struct in the hash? We'd save an allocation > > everywhere. > > Well, if we want to free hasher, then we want to keep string separate + > comment on obstack, right? I sill update patch tonight.
Yes, we want to have an obstack with just the strings and a comment that we have to keep that. Richard. > Honza > > > > Richard. > > > > > Honza > > > > > > * lto-streamer-in.c (file_name_obstack): New obstack. > > > (canon_file_name): Use it. > > > (lto_reader_init): Initialize it. > > > Index: lto-streamer-in.c > > > =================================================================== > > > --- lto-streamer-in.c (revision 277796) > > > +++ lto-streamer-in.c (working copy) > > > @@ -57,6 +57,7 @@ freeing_string_slot_hasher::remove (valu > > > > > > /* The table to hold the file names. */ > > > static hash_table<freeing_string_slot_hasher> *file_name_hash_table; > > > +static struct obstack file_name_obstack; > > > > > > > > > /* Check that tag ACTUAL has one of the given values. NUM_TAGS is the > > > @@ -113,8 +114,9 @@ canon_file_name (const char *string) > > > char *saved_string; > > > struct string_slot *new_slot; > > > > > > - saved_string = (char *) xmalloc (len + 1); > > > - new_slot = XCNEW (struct string_slot); > > > + saved_string = XOBNEWVEC (&file_name_obstack, char, len + 1); > > > + new_slot = XOBNEWVAR (&file_name_obstack, > > > + struct string_slot, sizeof (struct string_slot)); > > > memcpy (saved_string, string, len + 1); > > > new_slot->s = saved_string; > > > new_slot->len = len; > > > @@ -1723,6 +1725,7 @@ lto_reader_init (void) > > > lto_streamer_init (); > > > file_name_hash_table > > > = new hash_table<freeing_string_slot_hasher> (37); > > > + gcc_obstack_init (&file_name_obstack); > > > } > > > > > > > > > > > > > -- > > Richard Biener <rguent...@suse.de> > > SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg, > > Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg) > > -- Richard Biener <rguent...@suse.de> SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
