Add variants of the HA_ATOMIC* macros, prefixed with a _, that do the
atomic operation with no barrier generated by the compiler. It is expected
the developer adds barriers manually if needed.
When using the new __atomic* API, ask the compiler to generate barriers.
A variant of those functions that don't generate barriers will be added later.
Before that, using HA_ATOMIC* would not generate any barrier, and some parts
of the code should be reviewed and missing barriers should be added.
This should probably be backported to 1.8 and 1.9.
Implement __ha_barrier functions to be used when trying to protect data
modified by atomic operations (except when using HA_ATOMIC_STORE).
On intel, atomic operations either use the LOCK prefix and xchg, and both
atc as full barrier, so there's no need to add an extra barrier.
In this function we end up with successive locked operations then a
store barrier, and in addition the compiler has to emit less efficient
code due to a longer jump. There's no need for absolutely updating the
tasks_run_queue counter before clearing the task's leaf pointer, so
let's swap the two operations and benefit from a single barrier as much
as possible. This code is on the hot path and shows about half a percent
of improvement with 8 threads.
When haproxy is built with 51Degrees support, but not configured to use
51Degrees database, a segfault can occur when deinit_51degrees()
function is called, eg. during soft-stop on SIGUSR1 signal.
Only builds that use Pattern algorithm are affected.
This fix must be backported to all stable branches where 51Degrees
support is available. Additional adjustments are required for some
branches due to API and naming changes.
Before c8d5b95 the "maxconn" of the backend of dynamic "use_backend"
rules was not modified (this does not make sense and this is correct).
When implementing proxy_adjust_all_maxconn(), c8d5b95 commit missed this case.
With this patch we adjust the "maxconn" of the backend of such rules only if
they are not dynamic.
Without this patch reg-tests/http-rules/h00003.vtc could make haproxy crash.
deinit_log_buffers() can be called once per thread, however startup_logs
is common to all threads. So only attempt to free it once.
This should be backported to 1.9 and 1.8.
Tests show that it's slightly faster to have this field in the listener.
The cache walk patterns are under heavy stress and having only this field
written to in the bind_conf was wasting a cache line that was heavily
read. Let's move this close to the other entries already written to in
the listener. Warning, the position does have an impact on peak performance.
Now that the P2C algorithm for the accept queue is removed, we don't
need to map a number to a thread bit anymore, so let's remove all
these fields which are taking quite some space for no reason.
At this point, the random used in the hybrid queue distribution algorithm
provides little benefit over a periodic scan, can even have a slightly
worse worst case, and it requires to establish a mapping between a
discrete number and a thread ID among a mask.
This patch introduces a different approach using two indexes. One scans
the thread mask from the left, the other one from the right. The related
threads' loads are compared, and the least loaded one receives the new
connection. Then one index is adjusted depending on the load resulting
from this election, so that we start the next election from two known
lightly loaded threads.
This approach provides an extra 1% peak performance boost over the previous
one, which likely corresponds to the removal of the extra work on the
random and the previously required two mappings of index to thread.
A test was attempted with two indexes going in the same direction but it
was much less interesting because the same thread pairs were compared most
of the time with the load climbing in a ladder-like model. With the reverse
directions this cannot happen.
We already have my_ffsl() to find the lowest bit set in a word, and
this patch implements the search for the highest bit set in a word.
On x86 it uses the bsr instruction and on other architectures it
uses an efficient implementation.
By picking two randoms following the P2C algorithm, we seldom observe
asymmetric loads on bursts of small session counts. This is typically
what makes h2load take a bit of time to complete the last 100% because
if a thread gets two connections while the other ones only have one,
it takes twice the time to complete its work.
This patch proposes a modification of the p2c algorithm which seems
more suitable to this case : it mixes a rotating index with a random.
This way, we're certain that all threads are consulted in turn and at
the same time we're not forced to use the ones we're giving a chance.
This significantly increases the traffic rate. Now h2load shows faster
completion and the average request rates on H2 and the TLS resume rate
increases by a bit more than 5% compared to pure p2c.
The index was placed into the struct bind_conf because 1) it's faster
there and it's the best place to optimally distribute traffic among a
group of listeners. It's the only runtime-modified element there and
it will be quite cache-hot.
By using LIST_DEL_INIT() instead of LIST_DEL()+LIST_INIT() we manage
to bump the peak connection rate by no less than 3% on 8 threads.
The perf top profile shows much less contention in this area which
suffered from the second reload.
It turns out that we call LIST_DEL+LIST_INIT very frequently and that
the compiler doesn't know what pointers get modified in the e->n->p
and e->p->n dance, so when LIST_INIT() is called, it reloads these
pointers, which is quite a bit of a mess in terms of performance.
This patch adds LIST_DEL_INIT() to perform the two operations at once
using local temporary variables so that the compiler knows these
pointers are left unaffected.
This patch enables the part of this reg test which could not work due to a vtest
(formerly varnishtest) bug.
NOTE: You must have a vtest version with 4e43cc1 commit for this bug fix to make this
script succeed (see 4e43cc1fec
for more information).
This patch adds "protobuf" protocol buffers specific converter wich
may used in combination with "ungrpc" as first converter to extract
a protocol buffers field value. It is simply implemented reusing
protobuf_field_lookup() which is the protocol buffers specific parser already
used by "ungrpc" converter which only parse a gRPC header in addition of
parsing protocol buffers message.
Update the documentation for this new "protobuf" converter.
We move the code responsible of parsing protocol buffers messages
inside gRPC messages from sample.c to include/proto/protocol_buffers.h
so that to reuse it to cascade "ungrpc" converter.
In 84e417d8 ("MINOR: ssl: support Openssl 1.1.1 early callback for
switchctx") the code was extended to also support OpenSSL 1.1.1
(code already supported BoringSSL). A configuration check warning
was updated but with the wrong logic, the #ifdef needs a && instead
of an ||.
Reported in #54.
Should be backported to 1.8.
Emeric reports that when MAX_THREADS and/or MAX_PROCS are set to lower
values, referencing thread or process numbers higher than these limits
in cpu-map returns errors. This is annoying because these typically are
silent settings that are expected to be used only when set. Let's switch
back to LONGBITS for this limit.
Since the "wurfl" device detection engine was merged slightly more than
two years ago (2016-11-04), it never received a single fix nor update.
For almost two years it didn't receive even the minimal review or changes
needed to be compatible with threads, and it's remained build-broken for
about the last 9 months, consecutive to the last buffer API changes,
without anyone ever noticing! When asked on the list, nobody confirmed
using it :
https://www.mail-archive.com/haproxy@formilux.org/msg32516.html
And obviously nobody even cared to verify that it did still build. So we
are left with this broken code with no user and no maintainer. It might
even suffer from remotely exploitable vulnerabilities without anyone
being able to check if it presents any risk. It's a pain to update each
time there is an API change because it doesn't build as it depends on
external libraries that are not publicly accessible, leading to careful
blind changes. It slows down the whole project. This situation is not
acceptable at all.
It's time to cure the problem where it is. This patch removes all this
dead, non-buildable, non-working code. If anyone ever decides to use it,
which I seriously doubt based on history, it could be reintegrated, but
this time the following guarantees will be required :
- someone has to step up as a maintainer and have his name listed in
the MAINTAINERS file (I should have been more careful last time).
This person will take the sole blame for all issues and will be
responsible for fixing the bugs and incompatibilities affecting
this code, and for making it evolve to follow regular internal API
updates.
- support building on a standard distro with automated tools (i.e. no
more "click on this site, register your e-mail and download an
archive then figure how to place this into your build system").
Dummy libs are OK though as long as they allow the mainline code to
build and start.
- multi-threaded support must be fixed. I mean seriously, not worked
around with a check saying "please disable threads, we've been busy
fishing for the last two years".
This may be backported to 1.9 given that the code has never worked there
either, thus at least we're certain nobody will miss it.
For now on, "ungrpc" may take a second optional argument to provide
the protocol buffers types used to encode the field value to be extracted.
When absent the field value is extracted as a binary sample which may then
followed by others converters like "hex" which takes binary as input sample.
When this second argument is a type which does not match the one found by "ungrpc",
this field is considered as not found even if present.
With this patch we also remove the useless "varint" and "svarint" converters.
Update the documentation about "ungrpc" converters.
Parsing protocol buffer fields always consists in skip the field
if the field is not found or store the field value if found.
So, with this patch we factorize a little bit the code for "ungrpc" converter.
While the legacy code converts h2 to h1 and provides some control over
what is passed, in htx mode there is no such control and it is possible
to pass control chars and linear white spaces in the path, which are
possibly reencoded differently once passed to the H1 side.
HTX supports parse error reporting using a special flag. Let's check
the correctness of the :path pseudo header and report any anomaly in
the HTX flag.
Thanks to Jérôme Magnin for reporting this bug with a working reproducer.
This fix must be backported to 1.9 along with the two previous patches
("MINOR: htx: unconditionally handle parsing errors in requests or
responses" and "MINOR: mux-h2: always pass HTX_FL_PARSING_ERROR
between h2s and buf on RX").
