On Wed, 30 Jul 2014, Richard Biener wrote:
> On Wed, Jul 30, 2014 at 7:51 AM, Markus Trippelsdorf
> <[email protected]> wrote:
> > On 2014.07.29 at 15:10 +0200, Richard Biener wrote:
> >> On Tue, 29 Jul 2014, Richard Biener wrote:
> >>
> >> >
> >> > This re-organizes the LTO streamer to do compression transparently
> >> > in the data-streamer routines (and disables section compression
> >> > by defaulting to -flto-compression-level=0). This avoids
> >> > keeping the whole uncompressed sections in memory, only retaining
> >> > the compressed ones.
> >> >
> >> > The downside is that we lose compression of at least the string
> >> > parts (they are abusing the streaming interface quite awkwardly
> >> > and doing random-accesses with offsets into the uncompressed
> >> > section). With a little bit of surgery we can get that back I
> >> > think (but we'd have to keep the uncompressed piece in memory
> >> > somewhere which means losing the memory use advantage).
> >> >
> >> > Very lightly tested sofar (running lto.exp). I'll try a LTO
> >> > bootstrap now.
> >> >
> >> > I wonder what the change is on WPA memory use for larger
> >> > projects and what the effect on object file size is.
> >>
> >> Updated patch passing LTO bootstrap (one warning fix) and
> >> with a memory leak fixed.
> >
> > Testing with Firefox is impossible at the moment because of PR61885.
> > One thing I've noticed (before the ICE) is that virtual memory usage is
> > very high:
> >
> > Address Kbytes RSS Dirty Mode Mapping
> > 0000000000400000 16344 9084 0 r-x-- lto1
> > 00000000013f6000 36 36 28 rw--- lto1
> > 00000000013ff000 1072 276 276 rw--- [ anon ]
> > 00000000034aa000 10154940 1540384 1540384 rw--- [ anon ]
> > 00002acf04af2000 136 136 0 r-x-- ld-2.19.90.so
> > 00002acf04b14000 88 88 88 rw--- [ anon ]
> > ...
> > ---------------- ------- ------- -------
> > total kB 12022060 3388396 3377708
>
> Maybe there is still a memleak (just checked that LTOing int main() {}
> doesn't leak).
Found it:
Index: gcc/lto-section-in.c
===================================================================
--- gcc/lto-section-in.c.orig 2014-07-30 12:40:27.950225826 +0200
+++ gcc/lto-section-in.c 2014-07-30 12:37:44.179237102 +0200
@@ -249,7 +249,7 @@ lto_destroy_simple_input_block (struct l
struct lto_input_block *ib,
const char *data, size_t len)
{
- free (ib);
+ delete ib;
lto_free_section_data (file_data, section_type, NULL, data, len);
}
Richard.
