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| author | Michael Anthony Knyszek <mknyszek@google.com> | 2019-09-03 19:54:32 +0000 |
|---|---|---|
| committer | Michael Knyszek <mknyszek@google.com> | 2019-09-25 22:15:39 +0000 |
| commit | 9b30811280427a6d50d2558f316d62210e948656 (patch) | |
| tree | ecffe597a49cb2dfc77f54f812e8f17ed1fe2e02 /src/runtime/mstats.go | |
| parent | 78baea836d9f4312972e50e17dcff15ff63d155b (diff) | |
| download | go-9b30811280427a6d50d2558f316d62210e948656.tar.gz go-9b30811280427a6d50d2558f316d62210e948656.zip | |
runtime: redefine scavenge goal in terms of heap_inuse
This change makes it so that the scavenge goal is defined primarily in
terms of heap_inuse at the end of the last GC rather than next_gc. The
reason behind this change is that next_gc doesn't take into account
fragmentation, and we can fall into situation where the scavenger thinks
it should have work to do but there's no free and unscavenged memory
available.
In order to ensure the scavenge goal still tracks next_gc, we multiply
heap_inuse by the ratio between the current heap goal and the last heap
goal, which describes whether the heap is growing or shrinking, and by
how much.
Finally, this change updates the documentation for scavenging and
elaborates on why the scavenge goal is defined the way it is.
Fixes #34048.
Updates #32828.
Change-Id: I8deaf87620b5dc12a40ab8a90bf27932868610da
Reviewed-on: https://go-review.googlesource.com/c/go/+/193040
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src/runtime/mstats.go')
| -rw-r--r-- | src/runtime/mstats.go | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/src/runtime/mstats.go b/src/runtime/mstats.go index 421580eec3..09dbb26735 100644 --- a/src/runtime/mstats.go +++ b/src/runtime/mstats.go @@ -79,6 +79,8 @@ type mstats struct { last_gc_nanotime uint64 // last gc (monotonic time) tinyallocs uint64 // number of tiny allocations that didn't cause actual allocation; not exported to go directly + last_next_gc uint64 // next_gc for the previous GC + last_heap_inuse uint64 // heap_inuse at mark termination of the previous GC // triggerRatio is the heap growth ratio that triggers marking. // |