svn commit: r339655 - head/contrib/jemalloc/src
Edward Tomasz Napierala
trasz at FreeBSD.org
Tue Oct 23 14:11:36 UTC 2018
Author: trasz
Date: Tue Oct 23 14:11:35 2018
New Revision: 339655
URL: https://svnweb.freebsd.org/changeset/base/339655
Log:
Pick f80c97e477d1b3fe7778c65d9439d673738b4131 from upstream:
Rework the way jemalloc uses mmap(2) on FreeBSD.
This makes it directly use MAP_EXCL and MAP_ALIGNED() instead
of weird workarounds involving mapping at random places and then
unmapping parts of them.
Discussed with: jasone
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Modified:
head/contrib/jemalloc/src/pages.c
Modified: head/contrib/jemalloc/src/pages.c
==============================================================================
--- head/contrib/jemalloc/src/pages.c Tue Oct 23 13:54:54 2018 (r339654)
+++ head/contrib/jemalloc/src/pages.c Tue Oct 23 14:11:35 2018 (r339655)
@@ -180,6 +180,31 @@ pages_map(void *addr, size_t size, size_t alignment, b
assert(alignment >= PAGE);
assert(ALIGNMENT_ADDR2BASE(addr, alignment) == addr);
+#if defined(__FreeBSD__) && defined(MAP_EXCL)
+ /*
+ * FreeBSD has mechanisms both to mmap at specific address without
+ * touching existing mappings, and to mmap with specific alignment.
+ */
+ {
+ int prot = *commit ? PAGES_PROT_COMMIT : PAGES_PROT_DECOMMIT;
+ int flags = mmap_flags;
+
+ if (addr != NULL) {
+ flags |= MAP_FIXED | MAP_EXCL;
+ } else {
+ unsigned alignment_bits = ffs_zu(alignment);
+ assert(alignment_bits > 1);
+ flags |= MAP_ALIGNED(alignment_bits - 1);
+ }
+
+ void *ret = mmap(addr, size, prot, flags, -1, 0);
+ if (ret == MAP_FAILED) {
+ ret = NULL;
+ }
+
+ return ret;
+ }
+#endif
/*
* Ideally, there would be a way to specify alignment to mmap() (like
* NetBSD has), but in the absence of such a feature, we have to work
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