FreeBSD 9.1 excessive memory allocations [SOLVED]

Ben Morrow ben at morrow.me.uk
Thu Mar 28 06:52:08 UTC 2013


Quoth Unga <unga888 at yahoo.com>:
> 
> > I think you may be reading too much into the malloc manpage.  When it
> > mentions the use of per-thread small-object caches to avoid locking it's
> > talking about performance, not thread safety.  Allocations of all sizes
> > are thread-safe, the library just assumes that huge allocations are rare
> > enough that it doesn't use extra per-thread resources to avoid locking
> > for them, it just uses locking for huge blocks.
> 
> Good to note all allocations are thread safe in FreeBSD. Is it by some
> standard that malloc should be thread safe regardless the OS (BSDs,
> Linux, Windows, Android, etc)?

POSIX (well, SUSv4 at least) says that malloc and free must be
threadsafe. Note that Windows is not a POSIX system, though I belive
malloc is also always threadsafe on Windows.

Ben



More information about the freebsd-stable mailing list