It's usefull to keep runtime limits (fd and RAM) in postmortem and show them in
debug_parse_cli_show_dev(). Runtime limits are fed in feed_post_mortem_late(),
as we are sure that at this moment that all configuration was parsed and
all applied limits were alredy adjusted.
This is a preparation patch to extend postmortem in order to store runtime
limits. No need to perform getrlimit() in feed_post_mortem(), as we do this
in the very beginning of main() and we store initial fd limits in global
'rlim_fd_cur_at_boot' and 'rlim_fd_max_at_boot' variables.
It is more handy to use LIM2A in debug_parse_cli_show_dev(), as it allows to
show a custom string ("unlimited"), if a given limit value equals to 0.
normalize_rlim() handler is needed to convert properly RLIM_INFINITY to zero,
with the respect of type sizes, as rlim_t is always 4 bytes on 32bit and
64bit arch.
Let's extend postmortem to keep process runtime capabilities. This information
is gathered in feed_post_mortem_late(), as it is called just before
run_poll_loop() and we are sure at this moment, that all configuration
settings were successfully applied.
Let's extend post_mortem to store runtime process uid and gid.
This information is fed in feed_post_mortem_late(), just before calling
run_poll_loop(). Like this we are sure that all configuration settings were
successfully applied.
Process runtime information could be very useful in post_mortem, but we have to
collect it just before calling run_poll_loop(). Like this we are sure, that
we've successfully applied all configuration parameters and what we've
collected are the latest runtime settings.
The most appropraite place to collect such information is
feed_post_mortem_late(). It's called in each thread, but puts thread info in
the post_mortem only when it's in the last thread context. As it's called
under mutex lock, other threads at this moment have to wait until
feed_post_mortem_late() and another initialization functions from
per_thread_init_list will finish. The number of threads could be large. So, to
avoid spending a lot of time under the lock, let's exit immediately from
feed_post_mortem_late(), if it wasn't called in the last thread.
The "show threads" command introduced early in the 2.0 dev cycle uses
appctx->st1 to store its context (the number of the next thread to dump).
It goes back to an era where contexts were shared between the various
applets and the CLI's command handlers.
In fact it was already not good by then because st1 could possibly have
APPCTX_CLI_ST1_PAYLOAD (2) in it, that would make the dmup start at
thread 2, though it was extremely unlikely.
When contexts were finally cleaned up and moved to their own storage,
this one was overlooked, maybe due to using st1 instead of st2 like
most others. So it continues to rely on st1, and more recently some
new flags were appended, one of which is APPCTX_CLI_ST1_LASTCMD (16)
and is always there. This results in "show threads" to believe it must
start do dump from thread 16, and if this thread is not present, it can
simply crash the process. A tiny reproducer is:
global
nbthread 1
stats socket /tmp/sock1 level admin mode 666
$ socat /tmp/sock1 - <<< "show threads"
The fix for modern versions simply consists in assigning a context to
this command from the applet storage. We're using a single int, no need
for a struct, an int* will do it. That's valid till 2.6.
Prior to 2.6, better switch to appctx->ctx.cli.i0 or i1 which are all
properly initialized before the command is executed.
This must be backported to all stable versions.
Thanks to Andjelko Horvat for the report and the reproducer.
To make bug reporting easier for users, when crashing, let's suggest
what to do. Typically when a BUG_ON() matches, only the current thread
is useful the vast majority of the time, while when the watchdog
triggers, all threads are interesting.
The messages are printed at the end after the dump. We may adjust these
with wiki links in the future is more detailed instructions are relevant.
If haproxy compiled with Linux capabilities support, let's show process
capabilities before applying the configuration and at runtime in 'show dev'
command output. This maybe useful for debugging purposes. Especially in
cases, when process changes its UID and GID to non-priviledged or it
has started and run under non-priviledged UID and needed capabilities are
set by admin on the haproxy binary.
'show dev' command is very convenient to obtain haproxy debugging information,
while process is run in container. Let's extend its output with version and
cmdline. cmdline is useful in a way, as it shows absolute binary path and its
arguments, because sometimes the person, who is debugging failing container is
not the same, who has created and deployed it.
argc and argv are stored in the exported global structure, because
feed_post_mortem() is added as a post check function callback in the
post_check_list. So we can't simply change the signature of
feed_post_mortem(), without breaking other post check callbacks APIs.
Parsers are not supposed to modify argv, so we can safely bypass its pointer
to debug_parse_cli_show_dev(), without copying all argument stings somewhere
in the heap or on stack.
Limiting total allocatable process memory (VSZ) via setting RLIMIT_AS limit is
no longer effective, in order to restrict memory consumption at run time.
We can see from process memory map below, that there are many holes within
the process VA space, which bumps its VSZ to 1.5G. These holes are here by
many reasons and could be explaned at first by the full randomization of
system VA space. Now it is usually enabled in Linux kernels by default. There
are always gaps around the process stack area to trap overflows. Holes before
and after shared libraries could be explained by the fact, that on many
architectures libraries have a 'preferred' address to be loaded at; putting
them elsewhere requires relocation work, and probably some unshared pages.
Repetitive holes of 65380K are most probably correspond to the header that
malloc has to allocate before asked a claimed memory block. This header is
used by malloc to link allocated chunks together and for its internal book
keeping.
$ sudo pmap -x -p `pidof haproxy`
127136: ./haproxy -f /home/haproxy/haproxy/haproxy_h2.cfg
Address Kbytes RSS Dirty Mode Mapping
0000555555554000 388 64 0 r---- /home/haproxy/haproxy/haproxy
00005555555b5000 2608 1216 0 r-x-- /home/haproxy/haproxy/haproxy
0000555555841000 916 64 0 r---- /home/haproxy/haproxy/haproxy
0000555555926000 60 60 60 r---- /home/haproxy/haproxy/haproxy
0000555555935000 116 116 116 rw--- /home/haproxy/haproxy/haproxy
0000555555952000 7872 5236 5236 rw--- [ anon ]
00007fff98000000 156 36 36 rw--- [ anon ]
00007fff98027000 65380 0 0 ----- [ anon ]
00007fffa0000000 156 36 36 rw--- [ anon ]
00007fffa0027000 65380 0 0 ----- [ anon ]
00007fffa4000000 156 36 36 rw--- [ anon ]
00007fffa4027000 65380 0 0 ----- [ anon ]
00007fffa8000000 156 36 36 rw--- [ anon ]
00007fffa8027000 65380 0 0 ----- [ anon ]
00007fffac000000 156 36 36 rw--- [ anon ]
00007fffac027000 65380 0 0 ----- [ anon ]
00007fffb0000000 156 36 36 rw--- [ anon ]
00007fffb0027000 65380 0 0 ----- [ anon ]
...
00007ffff7fce000 4 4 0 r-x-- [ anon ]
00007ffff7fcf000 4 4 0 r---- /usr/lib/x86_64-linux-gnu/ld-2.31.so
00007ffff7fd0000 140 140 0 r-x-- /usr/lib/x86_64-linux-gnu/ld-2.31.so
...
00007ffff7ffe000 4 4 4 rw--- [ anon ]
00007ffffffde000 132 20 20 rw--- [ stack ]
ffffffffff600000 4 0 0 --x-- [ anon ]
---------------- ------- ------- -------
total kB 1499288 75504 72760
This exceeded VSZ makes impossible to start an haproxy process with 200M
memory limit, set at its initialization stage as RLIMIT_AS. We usually
have in this case such cryptic output at stderr:
$ haproxy -m 200 -f haproxy_quic.cfg
(null)(null)(null)(null)(null)(null)
At the same time the process RSS (a memory really used) is only 75,5M.
So to make process memory accounting more realistic let's base the memory
limit, set by -m option, on RSS measurement and let's use RLIMIT_DATA instead
of RLIMIT_AS.
RLIMIT_AS was used before, because earlier versions of haproxy always allocate
memory buffers for new connections, but data were not written there
immediately. So these buffers were not instantly counted in RSS, but were
always counted in VSZ. Now we allocate new buffers only in the case, when we
will write there some data immediately, so using RLIMIT_DATA becomes more
appropriate.
A compilation error occurs when using DEBUG_MEM_STATS due to a variable
now being unused in debug_iohandler_memstats() :
src/debug.c: In function ‘debug_iohandler_memstats’:
src/debug.c:1862:24: error: unused variable ‘sc’ [-Werror=unused-variable]
1862 | struct stconn *sc = appctx_sc(appctx);
| ^~
This is caused since the following commit :
94b8ed446f
MEDIUM: cli/applet: Stop to test opposite SC in I/O handler of CLI commands
This must not be backported.
The main CLI I/O handle is responsible to interrupt the processing on
shutdown/abort. It is not the responsibility of the I/O handler of CLI
commands to take care of it.
This new command, enabled only with "DEBUG_DEV", sends 2 or 20 traces
per task wakeup (depending on the verbosity level), and stops after 1M
wakeups per thread in order not to have to stop/start the process each
time it's fired.
We have two small messages and 18 larger ones from 20 to 270 bytes
each, so that the average size is approx 213 bytes counting headers
(the header adds approx 82 bytes), which matches what's generally
observed on average when traces are enabled in all muxes.
Typical figures show varations between 5.7M and 6.2M msg/s on an EPYC
in a 3C6T setup (single CCX), and 2.12M - 2.22M in a 24C48T setup
(across 8 CCX, with 8 thread groups).
While trying to reproduce another crash case involving lua filters
reported by @bgrooot on GH #2467, we found out that mixing filters loaded
from different contexts ('lua-load' vs 'lua-load-per-thread') for the same
stream isn't supported and may even cause the process to crash.
Historically, mixing lua-load and lua-load-per-threads for a stream wasn't
supported, but this changed thanks to 0913386 ("BUG/MEDIUM: hlua: streams
don't support mixing lua-load with lua-load-per-thread").
However, the above fix didn't consider lua filters's use-case properly:
unlike lua fetches, actions or even services, lua filters don't simply
use the stream hlua context as a "temporary" hlua running context to
process some hlua code. For fetches, actions.. hlua executions are
processed sequentially, so we simply reuse the hlua context from the
previous action/fetch to run the next one (this allows to bypass memory
allocations and initialization, thus it increases performance), unless
we need to run on a different hlua state-id, in which case we perform a
reset of the hlua context.
But this cannot work with filters: indeed, once registered, a filter will
last for the whole stream duration. It means that the filter will rely
on the stream hlua context from ->attach() to ->detach(). And here is the
catch, if for the same stream we register 2 lua filters from different
contexts ('lua-load' + 'lua-load-per-thread'), then we have an issue,
because the hlua stream will be re-created each time we switch between
runtime contexts, which means each time we switch between the filters (may
happen for each stream processing step), and since lua filters rely on the
stream hlua to carry context between filtering steps, this context will be
lost upon a switch. Given that lua filters code was not designed with that
in mind, it would confuse the code and cause unexpected behaviors ranging
from lua errors to crashing process.
So here we take another approach: instead of re-creating the stream hlua
context each time we switch between "global" and "per-thread" runtime
context, let's have both of them inside the stream directly as initially
suggested by Christopher back then when talked about the original issue.
For this we leverage hlua_stream_ctx_prepare() and hlua_stream_ctx_get()
helper functions which return the proper hlua context for a given stream
and state_id combination.
As for debugging infos reported after ha_panic(), we check for both hlua
runtime contexts to check if one of them was active when the panic occured
(only 1 runtime ctx per stream may be active at a given time).
This should be backported to all stable versions with 0913386
("BUG/MEDIUM: hlua: streams don't support mixing lua-load with lua-load-per-thread")
This commit depends on:
- "DEBUG: lua: precisely identify if stream is stuck inside lua or not"
[for versions < 2.9 the ha_thread_dump_one() part should be skipped]
- "MINOR: hlua: use accessors for stream hlua ctx"
For 2.4, the filters API didn't exist. However it may be a good idea to
backport it anyway because ->set_priv()/->get_priv() from tcp/http lua
applets may also be affected by this bug, plus it will ease code
maintenance. Of course, filters-related parts should be skipped in this
case.
When ha_panic() is called by the watchdog, we try to guess from
ha_task_dump() and ha_thread_dump_one() if the thread was stuck while
executing lua from the stream context. However we consider this is the
case by simply checking if the stream hlua context was set, but this is
not very precise because if the hlua context is set, then it simply means
that at least one lua instruction was executed at the stream level, not
that the stuck was currently executing lua when the panic occured.
This is especially true with filters, one could simply register a lua
filter that does nothing but this will still end up initializing the
stream hlua context for each stream. If the thread end up being stuck
during the stream handling, then debug dumping functions will report
that the stream was stuck while handling lua, which is not necessarilly
true, and could in fact confuse us even more.
So here we take another approach, we add the BUSY flag to hlua context:
this flag is set by hlua_ctx_resume() around lua_resume() call, this way
we can precisely tell if the thread was handling lua when it was
interrupted, and we rely on this flag in debug functions to check if the
thread was effectively stuck inside lua or not while processing the stream
No backport needed unless a commit depends on it.
In issue #2427 Ilya reports that gcc-14 rightfully complains about
sizeof() being placed in the left term of calloc(). There's no impact
but it's a bad pattern that gets copy-pasted over time. Let's fix the
few remaining occurrences (debug.c, halog, udp-perturb).
This can be backported to all branches, and the irrelevant parts dropped.
The "show dev" CLI command is still missing useful elements such as the
build options, SSL version etc. Let's just add the build features and
the build options there so that it's possible to collect all of this
from a running process without having to start the executable with -vv.
This is still dumped all at once from the parsing function since the
output is small. If it were to grow, this would possibly require to be
reworked to support a context.
It might be helpful to backport this to 2.9 since it can help narrow
down certain issues.
Here the idea is to collect components' versions and build options. The
main component is haproxy, but the API is made so that any sub-system
can easily add a component there (for example the detailed version of a
device detection lib, or some info about a lib loaded from Lua).
The elements are stored as a pointer to an array of structs and its count
so that it's sufficient to issue this in gdb to list them all at once:
print *post_mortem.components@post_mortem.nb_components
For now we collect name, version, toolchain, toolchain options, build
options and path. Maybe more could be useful in the future.
Having the libs and their addresses listed in the post_mortem struct
is also helpful. Sometimes it helps notice that one version is not the
expected one, e.g. due to some LD_LIBRARY_PATH. We don't emit it on
"show dev" however since that's already available via "show libs".
The last starting thread now copies the pthread ID and stack top of
each thread into post_mortem. That way it's as easy as issuing
"p post_mortem" in gdb to see all thread IDs and stack frames and more
easily map them to the threads met in a core.
Here we collect the original uid/gid/rlimits for FD and RAM since these
ones do affect behavior and are sometimes different from expected in
containers or when starting as a service.
When the x86 CPU flags show the "hypervisor" flag, we know we're running
inside QEMU, VMware or possibly other flavors of hypervisors. In this
case we'll report either "qemu", "vmware" or "yes" for other ones in
the "virt_techno" field, based on the DMI hardware vendor name,
otherwise "no" when the flag is not found.
The CPU model and type has significant impact on certain bugs, such
as contention issues caused by CPUs having split L3 caches, or stricter
memory models that exhibit some barrier issues. It's complicated though
because the info about the model depends on the arch. For example, x86
reports an SKU name while ARM rather reports the CPU core types, families
and versions for each CPU core. There, the SoC will sometimes be reported
in the device tree or DMI info instead. But we don't really care, it's
essentially useful to know if the code is running on an armv8.0 such as
A53, a 8.2 such as A55/A76/Neoverse etc. For MIPS the model appears to
generally be there, and in addition the SoC is often present in the
"system type" field before the first CPU, and the type of machine in the
"machine" field, to replace the missing DMI and DT, so they are also
collected. Note that only the first CPU is checked and reported, that's
expected to be vastly sufficient, since we're just trying to spot known
incompatibilities or issues.
If we detect we're running inside a container on Linux, let's check if
it seems to be docker. Docker usually creates a /.dockerenv file, which
is easy to check. It's uncertain whether it's always the case, but on the
few tested instances that was true, and we don't really care, what matters
is to place helpful debugging info for developers. When this file is
detected, we report "docker" instead of "yes" in the container techno.
Containers often cause significant trouble depending on how they're
set up, and they're not always trivial for their users to extract info
from. Here we're trying to detect if we're running inside a container
on Linux. There are plenty of approaches and none is perfectly clean
nor reliable, which makes sense since the goal is to remain transparent
enough.
One interesting approach is to rely on the observation that containers
generally do not expose most kernel threads, and that the very firsts
of them are extremely stable across all kernel versions: pid 2 was
called "keventd" in kernel 2.4, became "kthreadd" in kernel 2.6, and
has since not changed. This is true on all architectures tested, even
with highly stripped down kernels such as those found on 15 year-old
OpenWRT images. And this one doesn't appear inside containers. Thus
here we check if we find such a thread via /proc and whether it's
called keventd or kthreadd, to detect a container, and we set the
"cont_techno" variable to "yes" or "no" depending on what is found.
Let's extract some info about the system (board model, vendor etc),
this will indicate some hypervisors, some cloud instances or some
uncommon embedded boards etc. Typically, vmware, qemu and raspberry-pi
are visible here and can help during the troubleshooting session.
The goal here is to accumulate precious debugging information in a
struct that is easy to find in memory. It's aligned to 256-byte as
it also helps. We'll progressively add a lot of info about the
startup conditions, the operating system, the hardware and hypervisor
so as to limit the number of round trips between developers and users
during debugging sessions. Also, opening a core file with an hex editor
should often be sufficient to extract most of the info.
In addition, a new "show dev" command will show these information so
that they can be checked at runtime without having to wait for a crash
(e.g. if a limit is bad in a container, better know it early).
For now the struct only contains utsname that's fed at boot time.
Now when calling ha_panic() with a thread still under malloc_trim(),
we'll set a new tainted flag to easily report it, and the output
trace will report that this condition happened and will suggest to
use no-memory-trimming to avoid it in the future.
William suggested that since we can detect the presence of Lua in the
stack, let's combine it with stuck detection to set a new pair of flags
indicating a stuck Lua context and a stuck Lua shared context.
Now, executing an infinite loop in a Lua sample fetch function with
yield disabled crashes with tainted=0xe40 if loaded from a lua-load
statement, or tainted=0x640 from a lua-load-per-thread statement.
In addition, at the end of the panic dump, we can check if Lua was
seen stuck and emit recommendations about lua-load-per-thread and
the choice of dependencies depending on the presence of threads
and/or shared context.
This will make it easier to know that the panic function was called,
for the occasional case where the dump crashes and/or the stack is
corrupted and not much exploitable. Now at least it will be sufficient
to check the tainted value to know that someone called ha_panic(), and
it will also be usable to condition extra analysis.
Since commit c185bc465 ("MEDIUM: stream: now provide full stream dumps
in case of loops"), the stuck threads show the stream's pointer in the
margin since it appears immediately after a line feed. Let's add it after
the prefix and "stream=" to make the output more readable.
There used to be two working modes for this function, a single-line one
and a multi-line one, the difference being made on the "eol" argument
which could contain either a space or an LF (and with the prefix being
adjusted accordingly). Let's get rid of the single-line mode as it's
what limits the output contents because it's difficult to produce
exploitable structured data this way. It was only used in the rare case
of spinning streams and applets and these are the ones lacking info. Now
a spinning stream produces:
[ALERT] (3511) : A bogus STREAM [0x227e7b0] is spinning at 5581202 calls per second and refuses to die, aborting now! Please report this error to developers:
strm=0x227e7b0,c4a src=127.0.0.1 fe=public be=public dst=s1
txn=0x2041650,3000 txn.req=MSG_DONE,4c txn.rsp=MSG_RPBEFORE,0
rqf=1840000 rqa=8000 rpf=80000000 rpa=1400000
scf=0x24af280,EST,482 scb=0x24af430,EST,1411
af=(nil),0 sab=(nil),0
cof=0x7fdb28026630,300:H1(0x24a6f60)/RAW((nil))/tcpv4(33)
cob=0x23199f0,10000300:H1(0x24af630)/RAW((nil))/tcpv4(32)
filters={}
call trace(11):
(...)
Ilya reported in issue #2193 that the latest Fedora complains about us
passing NULL to epoll_wait() in the "debug dev fd" code to try to detect
an epoll FD. That was intentional to get the kernel's verifications and
make sure we're facing a poller, but since such a warning comes from the
libc, it's possible that it plans to replace the syscall with a wrapper
in the near future (e.g. epoll_pwait()), and that just hiding the NULL
(as was confirmed to work) might just postpone the problem.
Let's take another approach, instead we'll create a new dummy FD that
we'll try to remove from the epoll set using epoll_ctl(). Since we
created the FD we're certain it cannot be there. In this case (and
only in this case) epoll_ctl() will return -ENOENT, otherwise it will
typically return EINVAL or EBADF. It was verified that it works and
doesn't return false positives for other FD types. It should be
backported to the branches that contain a backport of the commit which
introduced the feature, apparently as far as 2.4:
5be7c198e ("DEBUG: cli: add a new "debug dev fd" expert command")
Task pointer check in debug_parse_cli_task() computes the theoric end
address of provided task pointer to check if it is valid or not thanks to
may_access() helper function.
However, relative ending address is calculated by adding task size to 't'
pointer (which is a struct task pointer), thus it will result to incorrect
address since the compiler automatically translates 't + x' to
't + x * sizeof(*t)' internally (with sizeof(*t) != 1 here).
Solving the issue by using 'ptr' (which is the void * raw address) as
starting address to prevent automatic address scaling.
This was revealed by coverity, see GH #2157.
No backport is needed, unless 9867987 ("DEBUG: cli: add "debug dev task"
to show/wake/expire/kill tasks and tasklets") gets backported.
Commit 986798718 ("DEBUG: cli: add "debug dev task" to show/wake/expire/kill
tasks and tasklets") caused a build failure on 32-bit platforms when parsing
the task's pointer. Let's use strtoul() and not strtoll(). No backport is
needed, unless the commit above gets backported.
The build without thread support was broken by commit b30ced3d8 ("BUG/MINOR:
debug: fix incorrect profiling status reporting in show threads") because
it accesses the isolated_thread variable that is not defined when threads
are disabled. In fact both the test on harmless and this one make no sense
without threads, so let's comment out the block and mark the related
variables as unused.
This may have to be backported to 2.7 if the commit above is.
Previously it would re-dump all threads to the same trash if the output
buffer was full, which it never was since the trash is of the same size.
Now it dumps one thread, copies it to the buffer and yields until it can
continue. Showing 256 threads works as expected.
Currently large setups cannot dump all their threads because they're
first dumped to the trash buffer, then copied to stderr. Here we can
now change this, instead we dump one thread at a time into the trash
and immediately send it to stderr. We also keep a copy into a local
trash chunk that's assigned to thread_dump_buffer so that a core file
still contains a copy of a large number of threads, which is generally
sufficient for the vast majority of situations.
It was verified that dumping 256 threads now produces ~55kB of output
and all of them are properly dumped.
The thread dump mechanism that is used by "show threads" and by the
panic dump is overly complicated due to an initial misdesign. It
firsts wakes all threads, then serializes their dumps, then releases
them, while taking extreme care not to face colliding dumps. In fact
this is not what we need and it reached a limit where big machines
cannot dump all their threads anymore due to buffer size limitations.
What is needed instead is to be able to dump *one* thread, and to let
the requester iterate on all threads.
That's what this patch does. It adds the thread_dump_buffer to the
struct thread_ctx so that the requester offers the buffer to the
thread that is about to be dumped. This buffer also serves as a lock.
A thread at rest has a NULL, a valid pointer indicates the thread is
using it, and 0x1 (NULL+1) is used by the dumped thread to tell the
requester it's done. This makes sure that a given thread is dumped
once at a time. In addition to this, the calling thread decides
whether it accesses the thread by itself or via the debug signal
handler, in order to get a backtrace. This is much saner because the
calling thread is free to do whatever it wants with the buffer after
each thread is dumped, and there is no dependency between threads,
once they've dumped, they're free to continue (and possibly to dump
for another requester if needed). Finally, when the THREAD_DUMP
feature is disabled and the debug signal is not used, the requester
accesses the thread by itself like before.
For now we still have the buffer size limitation but it will be
addressed in future patches.
In 2.3, commit 471425f51 ("BUG/MINOR: debug: Don't dump the lua stack
if it is not initialized") introduced the possibility to emit an empty
line when there's no Lua info to dump. The problem is that doing this
on the CLI in "show threads" marks the end of the output, and it may
affect some external tools. We need to make sure that LFs are only
emitted if there's something on the line and that all lines properly
start with the prefix.
This may be backported as far as 2.0 since the commit above was
backported there.
Sometimes it's convenient to test the effect of tasks running under
isolation, e.g. to validate the contents of the crash dumps. Let's
add an optional "isolated" keyword to "debug dev loop" for this.
Thread dumps include a field "prof" for each thread that reports whether
task profiling is currently active or not. It turns out that in 2.7-dev1,
commit 680ed5f28 ("MINOR: task: move profiling bit to per-thread")
mistakenly replaced it with a check for the current thread's bit in the
thread dumps, which basically is the only place where another thread is
being watched. The same mistake was done a few lines later by confusing
threads_want_rdv_mask with the profiling mask. This mask disappeared
in 2.7-dev2 with commit 598cf3f22 ("MAJOR: threads: change thread_isolate
to support inter-group synchronization"), though instead we know the ID
of the isolated thread. This commit fixes this and now reports "isolated"
instead of "wantrdv".
This can be backported to 2.7.
Commit 986798718 ("DEBUG: cli: add "debug dev task" to show/wake/expire/kill
tasks and tasklets") broke the build on windows due to this:
src/debug.c:940:95: error: array subscript has type char [-Werror=char-subscripts]
940 | caller && may_access(caller) && may_access(caller->func) && isalnum(*caller->func) ? caller->func : "0",
| ^~~~~~~~~~~~~
It's classical on platforms which implement ctype.h as macros instead of
functions, let's cast it as uchar. No backport is needed.
