Commit Graph

49 Commits

Author SHA1 Message Date
Kevin Svetlitski
41e0b857be Make headers self-contained by fixing #includes
Header files are now self-contained, which makes the relationships
between the files clearer, and crucially allows LSP tools like `clangd`
to function correctly in all of our header files. I have verified that
the headers are self-contained (aside from the various Windows shims) by
compiling them as if they were C files – in a follow-up commit I plan to
add this to CI to ensure we don't regress on this front.
2023-07-14 09:06:32 -07:00
Kevin Svetlitski
5a858c64d6 Reduce the memory overhead of sampled small allocations
Previously, small allocations which were sampled as part of heap
profiling were rounded up to `SC_LARGE_MINCLASS`. This additional memory
usage becomes problematic when the page size is increased, as noted in #2358.

Small allocations are now rounded up to the nearest multiple of `PAGE`
instead, reducing the memory overhead by a factor of 4 in the most
extreme cases.
2023-07-03 16:19:06 -07:00
Qi Wang
b75822bc6e Implement use-after-free detection using junk and stash.
On deallocation, sampled pointers (specially aligned) get junked and stashed
into tcache (to prevent immediate reuse).  The expected behavior is to have
read-after-free corrupted and stopped by the junk-filling, while
write-after-free is checked when flushing the stashed pointers.
2021-12-29 14:44:43 -08:00
Qi Wang
bf72188f80 Allow opt.tcache_max to accept small size classes.
Previously all the small size classes were cached.  However this has downsides
-- particularly when page size is greater than 4K (e.g. iOS), which will result
in much higher SMALL_MAXCLASS.

This change allows tcache_max to be set to lower values, to better control
resources taken by tcache.
2020-10-24 20:43:44 -07:00
David Goldblatt
6cdac3c573 Tcache: Make flush fractions configurable. 2020-05-16 13:34:23 -07:00
Yinan Zhang
fef9abdcc0 Cleanup tcache allocation logic
The logic in tcache allocation no longer involves profiling or
filling.
2020-05-11 12:24:56 -07:00
David Goldblatt
cd29ebefd0 Tcache: treat small and large cache bins uniformly 2020-04-14 15:20:19 -07:00
David Goldblatt
d701a085c2 Fast path: allow low-water mark changes.
This lets us put more allocations on an "almost as fast" path after a flush.
This results in around a 4% reduction in malloc cycles in prod workloads
(corresponding to about a 0.1% reduction in overall cycles).
2020-03-12 11:54:19 -07:00
David Goldblatt
ff6acc6ed5 Cache bin: simplify names and argument ordering.
We always start with the cache bin, then its info (if necessary).
2020-03-12 11:54:19 -07:00
David Goldblatt
e1dcc557d6 Cache bin: Only take the relevant cache_bin_info_t
Previously, we took an array of cache_bin_info_ts and an index, and dereferenced
ourselves.  But infos for other cache_bins aren't relevant to any particular
cache bin, so that should be the caller's job.
2020-03-12 11:54:19 -07:00
David Goldblatt
74d36d78ef Cache bin: Make ncached_max a query on the info_t. 2020-03-12 11:54:19 -07:00
David Goldblatt
909c501b07 Cache_bin: Shouldn't know about tcache.
Instead, have it take the cache_bin_info_ts to use by pointer.  While we're
here, add a src file for the cache bin.
2020-03-12 11:54:19 -07:00
David Goldblatt
79f1ee2fc0 Move junking out of arena/tcache code.
This is debug only and we keep it off the fast path.  Moving it here simplifies
the internal logic.

This never tries to junk on regions that were shrunk via xallocx.  I think this
is fine for two reasons:
- The shrunk-with-xallocx case is rare.
- We don't always do that anyway before this diff (it depends on the opt
  settings and extent hooks in effect).
2020-03-12 11:54:19 -07:00
Qi Wang
97dd79db6c Implement deallocation events.
Make the event module to accept two event types, and pass around the event
context.  Use bytes-based events to trigger tcache GC on deallocation, and get
rid of the tcache ticker.
2020-02-04 00:18:15 -08:00
Yinan Zhang
97f93fa0f2 Pull tcache GC events into thread event handler 2019-11-04 16:07:56 -08:00
Yinan Zhang
198f02e797 Pull prof_accumbytes into thread event handler 2019-11-04 15:21:16 -08:00
Qi Wang
937ca1db9f Store ncached_max * ptr_size in tcache_bin_info.
With the cache bin metadata switched to pointers, ncached_max is usually
accessed and timed by sizeof(ptr). Store the results in tcache_bin_info for
direct access, and add a helper function for the ncached_max value.
2019-08-19 12:23:24 -07:00
Qi Wang
7599c82d48 Redesign the cache bin metadata for fast path.
Implement the pointer-based metadata for tcache bins --
- 3 pointers are maintained to represent each bin;
- 2 of the pointers are compressed on 64-bit;
- is_full / is_empty done through pointer comparison;

Comparing to the previous counter based design --
- fast-path speed up ~15% in benchmarks
- direct pointer comparison and de-reference
- no need to access tcache_bin_info in common case
2019-08-19 12:21:44 -07:00
Qi Wang
e2c7584361 Simplify / refactor tcache_dalloc_large. 2019-08-14 13:08:23 -07:00
Qi Wang
9c5c2a2c86 Unify the signature of tcache_flush small and large. 2019-08-14 13:08:23 -07:00
Qi Wang
1f56115704 Fix tcache_flush (follow up cd2931a).
Also catch invalid tcache id.
2018-11-13 08:54:09 -08:00
Dave Watson
e2ab215324 refactor tcache_dalloc_small
Add a cache_bin_dalloc_easy (to match the alloc_easy function),
and use it in tcache_dalloc_small.  It will also be used in the
new free fastpath.
2018-11-12 13:20:37 -08:00
David Goldblatt
55e5cc1341 SC: Make some key size classes static.
The largest small class, smallest large class, and largest large class may all
be needed down fast paths; to avoid the risk of touching another cache line, we
can make them available as constants.
2018-07-12 20:53:06 -07:00
David Goldblatt
e904f813b4 Hide size class computation behind a layer of indirection.
This class removes almost all the dependencies on size_classes.h, accessing the
data there only via the new module sc.h, which does not depend on any
configuration options.

In a subsequent commit, we'll remove the configure-time size class computations,
doing them at boot time, instead.
2018-07-12 20:53:06 -07:00
gnzlbg
3d29d11ac2 Clean compilation -Wextra
Before this commit jemalloc produced many warnings when compiled with -Wextra
with both Clang and GCC. This commit fixes the issues raised by these warnings
or suppresses them if they were spurious at least for the Clang and GCC
versions covered by CI.

This commit:

* adds `JEMALLOC_DIAGNOSTIC` macros: `JEMALLOC_DIAGNOSTIC_{PUSH,POP}` are
  used to modify the stack of enabled diagnostics. The
  `JEMALLOC_DIAGNOSTIC_IGNORE_...` macros are used to ignore a concrete
  diagnostic.

* adds `JEMALLOC_FALLTHROUGH` macro to explicitly state that falling
  through `case` labels in a `switch` statement is intended

* Removes all UNUSED annotations on function parameters. The warning
  -Wunused-parameter is now disabled globally in
  `jemalloc_internal_macros.h` for all translation units that include
  that header. It is never re-enabled since that header cannot be
  included by users.

* locally suppresses some -Wextra diagnostics:

  * `-Wmissing-field-initializer` is buggy in older Clang and GCC versions,
    where it does not understanding that, in C, `= {0}` is a common C idiom
    to initialize a struct to zero

  * `-Wtype-bounds` is suppressed in a particular situation where a generic
    macro, used in multiple different places, compares an unsigned integer for
    smaller than zero, which is always true.

  * `-Walloc-larger-than-size=` diagnostics warn when an allocation function is
    called with a size that is too large (out-of-range). These are suppressed in
    the parts of the tests where `jemalloc` explicitly does this to test that the
    allocation functions fail properly.

* adds a new CI build bot that runs the log unit test on CI.

Closes #1196 .
2018-07-09 21:40:42 -07:00
Qi Wang
0fadf4a2e3 Add UNUSED to avoid compiler warnings. 2018-04-16 13:50:21 -07:00
David T. Goldblatt
901d94a2b0 Rename cache_alloc_easy to cache_bin_alloc_easy.
This lives in the cache_bin module; just a typo.
2017-12-18 16:29:10 -08:00
David T. Goldblatt
4bf4a1c4ea Pull out arena_bin_info_t and arena_bin_t into their own file.
In the process, kill arena_bin_index, which is unused.  To follow are several
diffs continuing this separation.
2017-12-18 16:29:10 -08:00
David Goldblatt
f3170baa30 Pull out caching for a bin into its own file.
This is the first step towards breaking up the tcache and arena (since they
interact primarily at the bin level).  It should also make a future arena
caching implementation more straightforward.
2017-08-16 17:48:44 -07:00
David Goldblatt
8261e581be Header refactoring: Pull size helpers out of jemalloc module. 2017-05-31 13:08:45 -07:00
Qi Wang
fc1aaf13fe Revert "Use trylock in tcache_bin_flush when possible."
This reverts commit 8584adc451.  Production
results not favorable.  Will investigate separately.
2017-05-01 14:49:42 -07:00
Qi Wang
d901a37775 Revert "Use try_flush first in tcache_dalloc."
This reverts commit b0c2a28280.  Production
benchmark shows this caused significant regression in both CPU and memory
consumption.  Will investigate separately later on.
2017-04-28 10:59:04 -07:00
Qi Wang
b0c2a28280 Use try_flush first in tcache_dalloc.
Only do must_flush if try_flush didn't manage to free anything.
2017-04-25 17:21:33 -07:00
Qi Wang
8584adc451 Use trylock in tcache_bin_flush when possible.
During tcache gc, use tcache_bin_try_flush_small / _large so that we can skip
items with their bins locked already.
2017-04-25 17:21:33 -07:00
David Goldblatt
31b43219db Header refactoring: size_classes module - remove from the catchall 2017-04-24 10:33:21 -07:00
David Goldblatt
bf2dc7e678 Header refactoring: ticker module - remove from the catchall and unify. 2017-04-24 10:33:21 -07:00
David Goldblatt
4d2e4bf5eb Get rid of most of the various inline macros. 2017-04-24 10:33:21 -07:00
Jason Evans
4403c9ab44 Remove --disable-tcache.
Simplify configuration by removing the --disable-tcache option, but
replace the testing for that configuration with
--with-malloc-conf=tcache:false.

Fix the thread.arena and thread.tcache.flush mallctls to work correctly
if tcache is disabled.

This partially resolves #580.
2017-04-21 10:06:12 -07:00
David Goldblatt
7ebc83894f Header refactoring: move jemalloc_internal_types.h out of the catch-all 2017-04-18 18:35:03 -07:00
David Goldblatt
f692e6c214 Header refactoring: move util.h out of the catchall 2017-04-18 18:35:03 -07:00
Qi Wang
b348ba29bb Bundle 3 branches on fast path into tsd_state.
Added tsd_state_nominal_slow, which on fast path malloc() incorporates
tcache_enabled check, and on fast path free() bundles both malloc_slow and
tcache_enabled branches.
2017-04-14 16:58:08 -07:00
Qi Wang
36bd90b962 Optimizing TSD and thread cache layout.
1) Re-organize TSD so that frequently accessed fields are closer to the
beginning and more compact.  Assuming 64-bit, the first 2.5 cachelines now
contains everything needed on tcache fast path, expect the tcache struct itself.

2) Re-organize tcache and tbins.  Take lg_fill_div out of tbin, and reduce tbin
to 24 bytes (down from 32). Split tbins into tbins_small and tbins_large, and
place tbins_small close to the beginning.
2017-04-07 14:06:17 -07:00
Qi Wang
0fba57e579 Get rid of tcache_enabled_t as we have runtime init support. 2017-04-07 10:42:29 -07:00
Qi Wang
fde3e20cc0 Integrate auto tcache into TSD.
The embedded tcache is initialized upon tsd initialization.  The avail arrays
for the tbins will be allocated / deallocated accordingly during init / cleanup.

With this change, the pointer to the auto tcache will always be available, as
long as we have access to the TSD.  tcache_available() (called in tcache_get())
is provided to check if we should use tcache.
2017-04-07 09:55:14 -07:00
Jason Evans
e8921cf2eb Convert extent_t's usize to szind.
Rather than storing usize only for large (and prof-promoted)
allocations, store the size class index for allocations that reside
within the extent, such that the size class index is valid for all
extents that contain extant allocations, and invalid otherwise (mainly
to make debugging simpler).
2017-03-22 18:33:32 -07:00
Jason Evans
f408643a4c Remove extraneous parens around return arguments.
This resolves #540.
2017-01-20 21:43:07 -08:00
Jason Evans
c4c2592c83 Update brace style.
Add braces around single-line blocks, and remove line breaks before
function-opening braces.

This resolves #537.
2017-01-20 21:43:07 -08:00
Jason Evans
ffbb7dac3d Remove leading blank lines from function bodies.
This resolves #535.
2017-01-13 14:49:24 -08:00
David Goldblatt
77cccac8cd Break up headers into constituent parts
This is part of a broader change to make header files better represent the
dependencies between one another (see
https://github.com/jemalloc/jemalloc/issues/533). It breaks up component headers
into smaller parts that can be made to have a simpler dependency graph.

For the autogenerated headers (smoothstep.h and size_classes.h), no splitting
was necessary, so I didn't add support to emit multiple headers.
2017-01-12 15:43:51 -08:00