0f8313659e
This diff adds a fastpath that assumes size <= SC_LOOKUP_MAXCLASS, and that we hit tcache. If either of these is false, we fall back to the previous codepath (renamed 'malloc_default'). Crucially, we only tail call malloc_default, and with the same kind and number of arguments, so that both clang and gcc tail-calling will kick in - therefore malloc() gets treated as a leaf function, and there are *no* caller-saved registers. Previously malloc() contained 5 caller saved registers on x64, resulting in at least 10 extra memory-movement instructions. In microbenchmarks this results in up to ~10% improvement in malloc() fastpath. In real programs, this is a ~1% CPU and latency improvement overall. |
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bin | ||
build-aux | ||
doc | ||
include | ||
m4 | ||
msvc | ||
scripts | ||
src | ||
test | ||
.appveyor.yml | ||
.autom4te.cfg | ||
.gitattributes | ||
.gitignore | ||
.travis.yml | ||
autogen.sh | ||
ChangeLog | ||
config.stamp.in | ||
configure.ac | ||
COPYING | ||
INSTALL.md | ||
jemalloc.pc.in | ||
Makefile.in | ||
README | ||
run_tests.sh | ||
TUNING.md |
jemalloc is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support. jemalloc first came into use as the FreeBSD libc allocator in 2005, and since then it has found its way into numerous applications that rely on its predictable behavior. In 2010 jemalloc development efforts broadened to include developer support features such as heap profiling and extensive monitoring/tuning hooks. Modern jemalloc releases continue to be integrated back into FreeBSD, and therefore versatility remains critical. Ongoing development efforts trend toward making jemalloc among the best allocators for a broad range of demanding applications, and eliminating/mitigating weaknesses that have practical repercussions for real world applications. The COPYING file contains copyright and licensing information. The INSTALL file contains information on how to configure, build, and install jemalloc. The ChangeLog file contains a brief summary of changes for each release. URL: http://jemalloc.net/