Old code was using recursion to traverse object graph.
New code uses an explicit stack, cutting the per-pointer
footprint to two words during the recursion and avoiding
the standard allocator and stack splitting code.
in test/garbage:
Reduces parser runtime by 2-3%
Reduces Peano runtime by 40%
Increases tree runtime by 4-5%
R=r
CC=golang-dev
https://golang.org/cl/2150042
This keeps fragmentation from delaying
garbage collections (and causing more fragmentation).
Cuts fresh godoc (with indexes) from 261M to 166M (120M live).
Cuts toy wc program from 50M to 8M.
Fixes#647.
R=r, cw
CC=golang-dev
https://golang.org/cl/257041
because free needs to mark the block as freed to
coordinate with the garbage collector.
(in C++ free can blindly put the block on the free list,
no questions asked, so the cache saves some work.)
R=iant
CC=golang-dev
https://golang.org/cl/206069
* specialize sweepspan as sweepspan0 and sweepspan1.
* in sweepspan1, inline "free" to avoid expensive mlookup.
R=iant
CC=golang-dev
https://golang.org/cl/206060
introduced explicit "data" symbol instead of etext
to mark beginning of data, so that using larger
alignment (i.e. 4MB like GNU loader) doesn't
confuse garbage collector.
split dodata into dodata and dobss in preparation
for putting the dynamic data + headers in the data
segment instead of stuffed at the beginning of the binary.
R=r
DELTA=52 (37 added, 3 deleted, 12 changed)
OCL=33610
CL=33618
saving of sp was too far away from use in scanstack;
the stack had changed since the sp was saved.
R=r
DELTA=9 (4 added, 2 deleted, 3 changed)
OCL=32232
CL=32237
* keep coherent SP/PC in gobuf
(i.e., SP that would be in use at that PC)
* gogocall replaces setspgoto,
should work better in presence of link registers
* delete unused system calls
only amd64; 386 is now broken
R=r
DELTA=548 (183 added, 183 deleted, 182 changed)
OCL=30381
CL=30442
not observed: do not use malloc to allocate stacks
during garbage collection, because it would make the
malloc data structures change underfoot.
R=r
DELTA=6 (3 added, 0 deleted, 3 changed)
OCL=30323
CL=30326
