Summary:
This patch includes several changes to reduce the overall footprint
of the allocator:
- for realloc'd chunks: only keep the same chunk when lowering the size
if the delta is within a page worth of bytes;
- when draining a cache: drain the beginning, not the end; we add pointers
at the end, so that meant we were draining the most recently added
pointers;
- change the release code to account for an freed up last page: when
scanning the pages, we were looking for pages fully covered by blocks;
in the event of the last page, if it's only partially covered, we
wouldn't mark it as releasable - even what follows the last chunk is
all 0s. So now mark the rest of the page as releasable, and adapt the
test;
- add a missing `setReleaseToOsIntervalMs` to the cacheless secondary;
- adjust the Android classes based on more captures thanks to pcc@'s
tool.
Reviewers: pcc, cferris, hctim, eugenis
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D75142
Summary:
Most of our larger data is dynamically allocated (via `map`) but it
became an hindrance with regard to init time, for a cost to benefit
ratio that is not great. So change the `TSD`s, `RegionInfo`, `ByteMap`
to be static.
Additionally, for reclaiming, we used mapped & unmapped a buffer each
time, which is costly. It turns out that we can have a static buffer,
and that there isn't much contention on it.
One of the other things changed here, is that we hard set the number
of TSDs on Android to the maximum number, as there could be a
situation where cores are put to sleep and we could miss some.
Subscribers: mgorny, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D74696
Summary:
This CL changes multiple things to improve performance (notably on
Android).We introduce a cache class for the Secondary that is taking
care of this mechanism now.
The changes:
- change the Secondary "freelist" to an array. By keeping free secondary
blocks linked together through their headers, we were keeping a page
per block, which isn't great. Also we know touch less pages when
walking the new "freelist".
- fix an issue with the freelist getting full: if the pattern is an ever
increasing size malloc then free, the freelist would fill up and
entries would not be used. So now we empty the list if we get to many
"full" events;
- use the global release to os interval option for the secondary: it
was too costly to release all the time, particularly for pattern that
are malloc(X)/free(X)/malloc(X). Now the release will only occur
after the selected interval, when going through the deallocate path;
- allow release of the `BatchClassId` class: it is releasable, we just
have to make sure we don't mark the batches containing batches
pointers as free.
- change the default release interval to 1s for Android to match the
current Bionic allocator configuration. A patch is coming up to allow
changing it through `mallopt`.
- lower the smallest class that can be released to `PageSize/64`.
Reviewers: cferris, pcc, eugenis, morehouse, hctim
Subscribers: phosek, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D73507
Summary:
This is a clean patch using the last diff of D69265, but using git
instead of svn, since svn went ro and arc was making my life harded
than it needed to be.
I was going to introduce a couple more lists and realized that our
lists are currently a bit all over the place. While we have a singly
linked list type relatively well defined, we are using doubly linked
lists defined on the fly for the stats and for the secondary blocks.
This CL adds a doubly linked list object, reorganizing the singly list
one to extract as much of the common code as possible. We use this
new type in the stats and the secondary. We also reorganize the list
tests to benefit from this consolidation.
There are a few side effect changes such as using for iterator loops
that are, in my opinion, cleaner in a couple of places.
Reviewers: hctim, morehouse, pcc, cferris
Reviewed By: hctim
Subscribers: jfb, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D69516
Summary:
This CL implements the memory reclaiming function `releaseFreeMemoryToOS`
and its associated classes. Most of this code was originally written by
Aleksey for the Primary64 in sanitizer_common, and I made some changes to
be able to implement 32-bit reclaiming as well. The code has be restructured
a bit to accomodate for freelist of batches instead of the freearray used
in the current sanitizer_common code.
Reviewers: eugenis, vitalybuka, morehouse, hctim
Reviewed By: vitalybuka
Subscribers: srhines, mgorny, delcypher, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D61214
llvm-svn: 359567
Kostya Kortchinsky