Commit Graph

38 Commits

Author SHA1 Message Date
David T. Goldblatt
723ccc6c27 Extents: Split out extent struct. 2019-09-23 23:06:27 -07:00
David T. Goldblatt
41187bdfb0 Extents: Break extent-struct/arena interactions
Specifically, the extent_arena_[g|s]et functions and the address randomization.

These are the only things that tie the extent struct itself to the arena code.
2019-09-23 23:06:27 -07:00
David T. Goldblatt
e7cf84a8dd Rearrange slab data and constants
The constants logically belong in the sc module. The slab data bitmap isn't
really scoped to an arena; move it to its own module.
2019-09-23 23:06:27 -07:00
Qi Wang
9a86c65abc Implement retain on Windows.
The VirtualAlloc and VirtualFree APIs are different because MEM_DECOMMIT cannot
be used across multiple VirtualAlloc regions.  To properly support decommit,
only allow merge / split within the same region -- this is done by tracking the
"is_head" state of extents and not merging cross-region.

Add a new state is_head (only relevant for retain && !maps_coalesce), which is
true for the first extent in each VirtualAlloc region.  Determine if two extents
can be merged based on the head state, and use serial numbers for sanity checks.
2019-07-23 22:18:55 -07:00
Qi Wang
7241bf5b74 Only read arena index from extent on the tcache flush path.
Add exten_arena_ind_get() to avoid loading the actual arena ptr in case we just
need to check arena matching.
2018-12-18 15:19:30 -08:00
Qi Wang
37b8913925 Add support for sharded bins within an arena.
This makes it possible to have multiple set of bins in an arena, which improves
arena scalability because the bins (especially the small ones) are always the
limiting factor in production workload.

A bin shard is picked on allocation; each extent tracks the bin shard id for
deallocation.  The shard size will be determined using runtime options.
2018-12-03 17:17:03 -08:00
Dave Watson
17aa470760 add extent_nfree_sub 2018-11-14 07:09:11 -08:00
Tyler Etzel
b664bd7935 Add logging for sampled allocations
- prof_opt_log flag starts logging automatically at runtime
- prof_log_{start,stop} mallctl for manual control
2018-08-01 13:27:11 -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
Qi Wang
eb1b08daae Fix an extent coalesce bug.
When coalescing, we should take both extents off the LRU list; otherwise decay
can grab the existing outer extent through extents_evict.
2017-11-16 15:32:02 -08:00
Dave Watson
d6feed6e66 Use tsd offset_state instead of atomic
While working on #852, I noticed the prng state is atomic.  This is the only
atomic use of prng in all of jemalloc.  Instead, use a threadlocal prng
state if possible to avoid unnecessary cache line contention.
2017-11-14 08:58:18 -08:00
David Goldblatt
d14bbf8d81 Add a "dumpable" bit to the extent state.
Currently, this is unused (i.e. all extents are always marked dumpable).  In the
future, we'll begin using this functionality.
2017-10-16 15:35:49 -07:00
David Goldblatt
8261e581be Header refactoring: Pull size helpers out of jemalloc module. 2017-05-31 13:08:45 -07:00
David Goldblatt
041e041e1f Header refactoring: unify and de-catchall mutex_pool. 2017-05-31 13:08:45 -07:00
David Goldblatt
18ecbfa89e Header refactoring: unify and de-catchall mutex module 2017-05-24 15:27:30 -07:00
David Goldblatt
3f685e8824 Protect the rtree/extent interactions with a mutex pool.
Instead of embedding a lock bit in rtree leaf elements, we associate extents
with a small set of mutexes.  This gets us two things:

- We can use the system mutexes.  This (hypothetically) protects us from
  priority inversion, and lets us stop doing a backoff/sleep loop, instead
  opting for precise wakeups from the mutex.
- Cuts down on the number of mutex acquisitions we have to do (from 4 in the
  worst case to two).

We end up simplifying most of the rtree code (which no longer has to deal with
locking or concurrency at all), at the cost of additional complexity in the
extent code: since the mutex protecting the rtree leaf elements is determined by
reading the extent out of those elements, the initial read is racy, so that we
may acquire an out of date mutex.  We re-check the extent in the leaf after
acquiring the mutex to protect us from this race.
2017-05-19 14:21:27 -07:00
Jason Evans
18a83681cf Refactor (MALLOCX_ARENA_MAX + 1) to be MALLOCX_ARENA_LIMIT.
This resolves #673.
2017-05-14 10:14:23 -07:00
David Goldblatt
268843ac68 Header refactoring: pages.h - unify and remove from catchall. 2017-04-25 09:51:38 -07:00
David Goldblatt
fa3ad730c4 Header refactoring: prng 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
881fbf762f Prefer old/low extent_t structures during reuse.
Rather than using a LIFO queue to track available extent_t structures,
use a red-black tree, and always choose the oldest/lowest available
during reuse.
2017-04-17 14:47:45 -07:00
Jason Evans
76b35f4b2f Track extent structure serial number (esn) in extent_t.
This enables stable sorting of extent_t structures.
2017-04-17 14:47:45 -07:00
David Goldblatt
0237870c60 Header refactoring: break out ql.h dependencies 2017-04-11 11:52:30 -07:00
David Goldblatt
bc32ec3503 Move arena-tracking atomics in jemalloc.c to C11-style 2017-04-05 16:25:37 -07:00
David Goldblatt
864adb7f42 Transition e_prof_tctx in struct extent to C11 atomics 2017-04-04 16:46:04 -07:00
Jason Evans
07f4f93434 Move arena_slab_data_t's nfree into extent_t's e_bits.
Compact extent_t to 128 bytes on 64-bit systems by moving
arena_slab_data_t's nfree into extent_t's e_bits.

Cacheline-align extent_t structures so that they always cross the
minimum number of cacheline boundaries.

Re-order extent_t fields such that all fields except the slab bitmap
(and overlaid heap profiling context pointer) are in the first
cacheline.

This resolves #461.
2017-03-27 22:43:39 -07:00
Jason Evans
735ad8210c Pack various extent_t fields into a bitfield.
This reduces sizeof(extent_t) from 160 to 136 on x64.
2017-03-25 23:30:13 -07:00
Jason Evans
0591c204b4 Store arena index rather than (arena_t *) in extent_t. 2017-03-25 23:30:13 -07:00
Jason Evans
99d68445ef Incorporate szind/slab into rtree leaves.
Expand and restructure the rtree API such that all common operations can
be achieved with minimal work, regardless of whether the rtree leaf
fields are independent versus packed into a single atomic pointer.
2017-03-22 18:33:32 -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
e201e24904 Perform delayed coalescing prior to purging.
Rather than purging uncoalesced extents, perform just enough incremental
coalescing to purge only fully coalesced extents.  In the absence of
cached extent reuse, the immediate versus delayed incremental purging
algorithms result in the same purge order.

This resolves #655.
2017-03-07 10:25:12 -08:00
Jason Evans
d27f29b468 Disentangle arena and extent locking.
Refactor arena and extent locking protocols such that arena and
extent locks are never held when calling into the extent_*_wrapper()
API.  This requires extra care during purging since the arena lock no
longer protects the inner purging logic.  It also requires extra care to
protect extents from being merged with adjacent extents.

Convert extent_t's 'active' flag to an enumerated 'state', so that
retained extents are explicitly marked as such, rather than depending on
ring linkage state.

Refactor the extent collections (and their synchronization) for cached
and retained extents into extents_t.  Incorporate LRU functionality to
support purging.  Incorporate page count accounting, which replaces
arena->ndirty and arena->stats.retained.

Assert that no core locks are held when entering any internal
[de]allocation functions.  This is in addition to existing assertions
that no locks are held when entering external [de]allocation functions.

Audit and document synchronization protocols for all arena_t fields.

This fixes a potential deadlock due to recursive allocation during
gdump, in a similar fashion to b49c649bc1
(Fix lock order reversal during gdump.), but with a necessarily much
broader code impact.
2017-02-01 16:43:46 -08:00
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