| Age | Commit message (Collapse) | Author |
|---|
|
|
|
|
|
|
|
|
|
This commit replaces the old memory instrumentation with a new
implementation that scans carriers instead of wrapping
erts_alloc/erts_free. The old implementation could not extract
information without halting the emulator, had considerable runtime
overhead, and the memory maps it produced were noisy and lacked
critical information.
Since the new implementation walks through existing data structures
there's no longer a need to start the emulator with special flags to
get information about carrier utilization/fragmentation. Memory
fragmentation is also easier to diagnose as it's presented on a
per-carrier basis which eliminates the need to account for "holes"
between mmap segments.
To help track allocations, each allocation can now be tagged with
what it is and who allocated it at the cost of one extra word per
allocation. This is controlled on a per-allocator basis with the
+M<S>atags option, and is enabled by default for binary_alloc and
driver_alloc (which is also used by NIFs).
|
|
|
|
Communication between Erlang processes has conceptually always been
performed through asynchronous signaling. The runtime system
implementation has however previously preformed most operation
synchronously. In a system with only one true thread of execution, this
is not problematic (often the opposite). In a system with multiple threads
of execution (as current runtime system implementation with SMP support)
it becomes problematic. This since it often involves locking of structures
when updating them which in turn cause resource contention. Utilizing
true asynchronous communication often avoids these resource contention
issues.
The case that triggered this change was contention on the link lock due
to frequent updates of the monitor trees during communication with a
frequently used server. The signal order delivery guarantees of the
language makes it hard to change the implementation of only some signals
to use true asynchronous signaling. Therefore the implementations
of (almost) all signals have been changed.
Currently the following signals have been implemented as true
asynchronous signals:
- Message signals
- Exit signals
- Monitor signals
- Demonitor signals
- Monitor triggered signals (DOWN, CHANGE, etc)
- Link signals
- Unlink signals
- Group leader signals
All of the above already defined as asynchronous signals in the
language. The implementation of messages signals was quite
asynchronous to begin with, but had quite strict delivery constraints
due to the ordering guarantees of signals between a pair of processes.
The previously used message queue partitioned into two halves has been
replaced by a more general signal queue partitioned into three parts
that service all kinds of signals. More details regarding the signal
queue can be found in comments in the erl_proc_sig_queue.h file.
The monitor and link implementations have also been completely replaced
in order to fit the new asynchronous signaling implementation as good
as possible. More details regarding the new monitor and link
implementations can be found in the erl_monitor_link.h file.
|
|
to replace DFLAGS_STRICT_ORDER_DELIVERY
and remove that compile time dependency.
|
|
for kernel to ask erts about distribution flags
and keep this info in one place.
|
|
|
|
* lukas/stdlib/maps_iterators/OTP-14012:
erts: Limit size of first iterator for hashmaps
Update primary bootstrap
Update preloaded modules
erts: Remove erts_internal:maps_to_list/2
stdlib: Make io_lib and io_lib_pretty use maps iterator
erts: Implement batching maps:iterator
erts: Implement maps path iterator
erts: Implement map iterator using a stack
stdlib: Introduce maps iterator API
Conflicts:
bootstrap/lib/stdlib/ebin/io_lib.beam
bootstrap/lib/stdlib/ebin/io_lib_pretty.beam
erts/emulator/beam/bif.tab
erts/preloaded/ebin/erlang.beam
erts/preloaded/ebin/erts_internal.beam
erts/preloaded/ebin/zlib.beam
|
|
|
|
This function is no longer needed as maps:iterator has
now been implemented.
|
|
This iterator implementation fetches multiple elements to
iterate over in one call to erts_internal:maps_next instead
of one at a time. This means that the memory usage will go
up for the iterator as we are buffering elements, but the
usage is still bounded.
In this implementation the max memory usage is 1000 words.
Using this approach makes the iterator as fast as using
maps:to_list, so maps:iterator/2 has been removed.
|
|
and drop _id suffix.
|
|
|
|
Conflicts:
erts/emulator/beam/bif.c
erts/emulator/beam/dist.c
erts/emulator/beam/dist.h
erts/emulator/beam/erl_bif_info.c
erts/emulator/beam/erl_node_tables.c
erts/emulator/beam/erl_node_tables.h
erts/emulator/beam/external.c
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
26b59dfe67 introduced the new 'AtU8' chunk to support
Unicode atoms.
make_preload strips the pre-loaded BEAM files so that they
only contain essential chunks. It expects to find the old
'Atom' chunk.
Teach make_preload to read the new 'AtU8' chunk instead of the old
chunk. Also produce a nice error message if someone by mistake
compiles the pre-loaded modules with an OTP 19 compiler.
|
|
|
|
* maint:
Update preloaded
erts: Correct type declaration of match specification head
Conflicts:
erts/preloaded/ebin/erlang.beam
erts/preloaded/ebin/erts_internal.beam
|
|
|
|
* maint:
erts: Add nif_SUITE:t_on_load
erts: Improve nif_SUITE:upgrade test
Don't leak old code when loading a modules with an on_load function
Conflicts:
erts/preloaded/ebin/erts_code_purger.beam
erts/preloaded/ebin/erts_internal.beam
erts/preloaded/src/erts_code_purger.erl
|
|
Normally, calling code:delete/1 before re-loading the code for a
module is unnecessary but causes no problem.
But there will be be problems if the new code has an on_load function.
Code with an on_load function will always be loaded as old code
to allowed it to be easily purged if the on_load function would fail.
If the on_load function succeeds, the old and current code will be
swapped.
So in the scenario where code:delete/1 has been called explicitly,
there is old code but no current code. Loading code with an
on_load function will cause the reference to the old code to be
overwritten. That will at best cause a memory leak, and at worst
an emulator crash (especially if NIFs are involved).
To avoid that situation, we will put the code with the on_load
function in a special, third slot in Module.
ERL-240
|
|
|
|
|
|
|
|
Ensure that we cannot get any dangling pointers into code that
has been purged. This is done by a two phase purge. At first
phase all fun entries pointing into the code to purge are marked
for purge. All processes trying to call these funs will be suspended
and by this we avoid getting new direct references into the code.
When all processes has been checked, these processes are resumed.
The new purge strategy now also completely ignore the existence of
indirect references to the code (funs). If such exist, they will
cause bad fun exceptions to the caller, but will not prevent a
soft purge or cause a kill of a process having such live references
during a hard purge. This since it is impossible to give any
guarantees that no processes in the system have such indirect
references. Even when the system is completely clean from such
references, new ones can appear via distribution and/or disk.
|
|
|
|
|
|
|
|
|
|
|
|
Conflicts:
erts/emulator/beam/erl_alloc.types
erts/emulator/beam/erl_bif_info.c
erts/emulator/beam/erl_process.c
erts/preloaded/ebin/erts_internal.beam
|
|
|
|
|
|
* sverk/safe-purging/OTP-13122:
erts: Fix harmless dialyzer warnings
|
|
|
|
|
|
|
|
by ignoring literals.
erts_internal:check_process_code will be called again anyway
(with option {copy_literals, true}) before the module is actually purged.
No need to check literals twice.
|
|
Move impl from erlang to erts_internal. Cut and paste.
|
|
as it's not a public interface.
|
|
Problem: erlang:purge_module/1 is not safe in the sense
that very bad things may happen if the code to be purged
is still referred to by live processes.
Introduce erts_internal:purge_module which is the same as the old
erlang:purge_module BIF (except it returns false if no such old module).
Implement erlang:purge_module in Erlang and let it invoke
erts_code_purger for safe purging where all clogging processes
first are killed.
|
