When jemalloc is used as a libc malloc replacement (i.e. not prefixed),
some particular setups may end up inconsistently calling malloc from
libc and free from jemalloc, or the other way around.
glibc provides hooks to make its functions use alternative
implementations. Use them.
Submitted by Karl Tomlinson and Mike Hommey.
Do not enforce minimum alignment in memalign(). This is a non-standard
function, and there is disagreement over whether to enforce minimum
alignment. Solaris documentation (whence memalign() originated) says
that minimum alignment is required:
The value of alignment must be a power of two and must be greater than
or equal to the size of a word.
However, Linux's manual page says in its NOTES section:
memalign() may not check that the boundary parameter is correct.
This is descriptive rather than prescriptive, but applications with
bad assumptions about memalign() exist, so be as forgiving as possible.
Reported by Mike Hommey.
Program-generate small size class tables for all valid combinations of
LG_TINY_MIN, LG_QUANTUM, and PAGE_SHIFT. Use the appropriate table to generate
all relevant data structures, and remove the distinction between
tiny/quantum/cacheline/subpage bins.
Remove --enable-dynamic-page-shift. This option didn't prove useful in
practice, and it prevented optimizations.
Add Tilera architecture support.
Remove opt.lg_prof_bt_max, and hard code it to 7. The original
intention of this option was to enable faster backtracing by limiting
backtrace depth. However, this makes graphical pprof output very
difficult to interpret. In practice, decreasing sampling frequency is a
better mechanism for limiting profiling overhead.
Remove the opt.lg_prof_tcmax option and hard-code a cache size of 1024.
This setting is something that users just shouldn't have to worry about.
If lock contention actually ends up being a problem, the simple solution
available to the user is to reduce sampling frequency.
Convert configuration-related cpp conditional logic to use static
constant variables, e.g.:
#ifdef JEMALLOC_DEBUG
[...]
#endif
becomes:
if (config_debug) {
[...]
}
The advantage is clearer, more concise code. The main disadvantage is
that data structures no longer have conditionally defined fields, so
they pay the cost of all fields regardless of whether they are used. In
practice, this is only a minor concern; config_stats will go away in an
upcoming change, and config_prof is the only other major feature that
depends on more than a few special-purpose fields.
Add a missing prof_malloc() call in allocm(). Before this fix, negative
object/byte counts could be observed in heap profiles for applications
that use allocm().
Rewrite prof_alloc_prep() as a cpp macro, PROF_ALLOC_PREP(), in order to
remove any doubt as to whether an additional stack frame is created.
Prior to this change, it was assumed that inlining would reduce the
total number of frames in the backtrace, but in practice behavior wasn't
completely predictable.
Create imemalign() and call it from posix_memalign(), memalign(), and
valloc(), so that all entry points require the same number of stack
frames to be ignored during backtracing.
Properly handle boundary conditions for sampled region promotion in
rallocm(). Prior to this fix, some combinations of 'size' and 'extra'
values could cause erroneous behavior. Additionally, size class
recording for promoted regions was incorrect.
