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Merged
1 commit merged into from
Feb 10, 2011
Merged

Use a well-known bridge name for the host internal management network #17

1 commit merged into from
Feb 10, 2011

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@djs55
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@djs55 djs55 commented Feb 9, 2011

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CA-6996: the host internal management network now uses a well-known c…
2cc02e5 
…onstant bridge name, so it can be referenced from global firewall rules.

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
sharady pushed a commit to sharady/xen-api that referenced this pull request May 11, 2015
@djs55
Merge pull request xapi-project#17 from djs55/search-xcp-path
d75cf69 
Search XCP_PATH as well as PATH
koushikcgit pushed a commit to koushikcgit/xen-api that referenced this pull request Aug 7, 2015
@djs55
Merge pull request xapi-project#17 from robhoes/xenlight4
f805c6a 
Adding the Xenlight backend!
koushikcgit pushed a commit to koushikcgit/xen-api that referenced this pull request Aug 7, 2015
@djs55
Merge pull request xapi-project#17 from simonjbeaumont/cp-5970
47073ac 
CP-5970: Move xenops' cancellable watch paths
kc284 pushed a commit to kc284/xen-api that referenced this pull request Mar 11, 2021
Merge pull request xapi-project#17 from kc284/master
4279c8a 
CA-126115: Missing namespace was causing compilation error.
robhoes pushed a commit to robhoes/xen-api that referenced this pull request Jul 6, 2021
@djs55
Merge pull request xapi-project#17 from johnelse/fix-async-build
2f44d5d 
Fix build against async
robhoes pushed a commit that referenced this pull request Sep 14, 2021
@johnelse
Merge pull request #17 from siddharthv/blkback_stats
34b11e7 
CA-136792: Create IO metrics from '/dev/shm' and sysfs.
robhoes pushed a commit that referenced this pull request Sep 14, 2021
@johnelse
Merge pull request #17 from johnelse/build-tidying
31a86ac 
Build tidying
robhoes pushed a commit that referenced this pull request Sep 14, 2021
@johnelse
Merge pull request #17 from kaifengz/CA-142270-master
239d969 
CA-142270: Include blktap3 perf data to host level stats
robhoes pushed a commit that referenced this pull request Sep 14, 2021
@johnelse
Merge pull request #17 from simonjbeaumont/reporter-state
944e27b 
Create reporter with Stopped state
psafont pushed a commit to psafont/xen-api that referenced this pull request Sep 20, 2021
@thomassa
Merge pull request xapi-project#17 from thomassa/back-compat-switch
79c2a44 
CP-12512 A switch to set stunnel protocol version
robhoes pushed a commit to robhoes/xen-api that referenced this pull request Sep 21, 2021
@psafont
Merge pull request xapi-project#17 from psafont/noext
3b16fdf 
 CP-33121: remove stdext's monadic
psafont pushed a commit to psafont/xen-api that referenced this pull request Oct 19, 2021
@robhoes
Merge pull request xapi-project#17 from jonludlam/CA-105789
2721841 
CA-105789
lindig pushed a commit to lindig/xen-api that referenced this pull request Dec 17, 2021
@johnelse
Merge pull request xapi-project#17 from fillzero/CP-17694_M1
6545681 
CP-17694: Log stdout/stderr from device model
robhoes pushed a commit to robhoes/xen-api that referenced this pull request Jan 10, 2022
@lindig
Merge pull request xapi-project#17 from lindig/CP-30062
0d1f0ca 
CP-30062 update dependencies for OCaml 4.07, Lwt 4.1
robhoes pushed a commit to robhoes/xen-api that referenced this pull request Jan 10, 2022
@lindig
Merge pull request xapi-project#17 from gaborigloi/fix_whitespace
0422950 
main.ml: ocp-indent and remove trailing whitespace
robhoes added a commit to robhoes/xen-api that referenced this pull request Apr 7, 2022
@robhoes
Merge pull request xapi-project#17 from rafalmiel/systemd-cp-15132
5d20769 
CP-15132: Systemd conversion
psafont added a commit to psafont/xen-api that referenced this pull request Mar 17, 2023
@psafont
Merge pull request xapi-project#17 from xapi-project/private/edvint/dev
5bfa4d9
edwintorok added a commit to edwintorok/xen-api that referenced this pull request Oct 10, 2023
@edwintorok
Workaround: avoid sleep(1) call by crypt_r
c916e7d 
Using an off-cpu flamegraph I identified that concurrent PAM calls are slow due to a call to `sleep(1)`.
`pam_authenticate` calls `crypt_r` which calls `NSSLOW_Init` which on first use will try to initialize the just `dlopen`-ed library.
If it encounters a race condition it does a `sleep(1)`. This race condition can be quite reliably reproduced when performing a lot of PAM authentications from multiple threads in parallel.

GDB can also be used to confirm this by putting a breakpoint on `sleep`:
```
 #0  __sleep (seconds=seconds@entry=1) at ../sysdeps/unix/sysv/linux/sleep.c:42
 #1  0x00007ffff1548e22 in freebl_RunLoaderOnce () at lowhash_vector.c:122
 #2  0x00007ffff1548f31 in freebl_InitVector () at lowhash_vector.c:131
 #3  NSSLOW_Init () at lowhash_vector.c:148
 #4  0x00007ffff1b8f09a in __sha512_crypt_r (key=key@entry=0x7fffd8005a60 "pamtest-edvint", salt=0x7ffff31e17b8 "dIJbsXKc0",
 xapi-project#5  0x00007ffff1b8d070 in __crypt_r (key=key@entry=0x7fffd8005a60 "pamtest-edvint", salt=<optimized out>,
 xapi-project#6  0x00007ffff1dc9abc in verify_pwd_hash (p=p@entry=0x7fffd8005a60 "pamtest-edvint", hash=<optimized out>, nullok=nullok@entry=0) at passverify.c:111
 xapi-project#7  0x00007ffff1dc9139 in _unix_verify_password (pamh=pamh@entry=0x7fffd8002910, name=0x7fffd8002ab0 "pamtest-edvint", p=0x7fffd8005a60 "pamtest-edvint", ctrl=ctrl@entry=8389156) at support.c:777
 xapi-project#8  0x00007ffff1dc6556 in pam_sm_authenticate (pamh=0x7fffd8002910, flags=<optimized out>, argc=<optimized out>, argv=<optimized out>) at pam_unix_auth.c:178
 xapi-project#9  0x00007ffff7bcef1a in _pam_dispatch_aux (use_cached_chain=<optimized out>, resumed=<optimized out>, h=<optimized out>, flags=1, pamh=0x7fffd8002910) at pam_dispatch.c:110
 xapi-project#10 _pam_dispatch (pamh=pamh@entry=0x7fffd8002910, flags=1, choice=choice@entry=1) at pam_dispatch.c:426
 xapi-project#11 0x00007ffff7bce7e0 in pam_authenticate (pamh=0x7fffd8002910, flags=flags@entry=1) at pam_auth.c:34
 xapi-project#12 0x00000000005ae567 in XA_mh_authorize (username=username@entry=0x7fffd80028d0 "pamtest-edvint", password=password@entry=0x7fffd80028f0 "pamtest-edvint", error=error@entry=0x7ffff31e1be8) at xa_auth.c:83
 xapi-project#13 0x00000000005adf20 in stub_XA_mh_authorize (username=<optimized out>, password=<optimized out>) at xa_auth_stubs.c:42
 xapi-project#14 0x00000000004a0a6a in camlDune__exe__Bench_pam__pam_authenticate$27_320 () at ocaml/tests/bench/pam/bench_pam.ml:63
 xapi-project#15 0x00000000004a1113 in camlEzbechamel_concurrent__worker_loop_359 () at ocaml/tests/bench/lib/concurrent/ezbechamel_concurrent.ml:36
 xapi-project#16 0x00000000005935b9 in camlStdlib__Fun__protect_317 ()
 xapi-project#17 0x00000000004a1955 in camlThread__fun_850 ()
 xapi-project#18 0x00000000005d6401 in caml_start_program ()
 xapi-project#19 0x00000000005cd0fd in caml_callback_exn ()
 xapi-project#20 0x00000000005af810 in caml_thread_start ()
 xapi-project#21 0x00007ffff79b7e25 in start_thread (arg=0x7ffff31e2700) at pthread_create.c:308
 xapi-project#22 0x00007ffff71dbbad in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113
```

`pam_start` and `pam_end` doesn't help here, because on `pam_end` the library is `dlclose`-ed, so on next `pam_authenticate` it will have to go through the initialization code again.
(This initialization code would've belonged into `pam_start`, not `pam_authenticate`, but there are several layers here including a call to `crypt_r`).

To avoid this link with `libcrypt` and call `crypt_r` once ourselves (and ensure it loads `libfreeblpriv3` by using the sha512 prefix).
That way the library will stay loaded (we'll hold a reference count on it), and the `dlclose` done by PAM won't unload it.

Confirmed that there are no `sleep` calls now, and the results are also visible when running the benchmark targeted to the with and without fix code:
```
╭─────────────────────────────────────────────────┬───────────────────────────┬───────────────────────────┬───────────────────────────╮
│name                                             │  major-allocated          │  minor-allocated          │  monotonic-clock          │
├─────────────────────────────────────────────────┼───────────────────────────┼───────────────────────────┼───────────────────────────┤
│  concurrent authenticate (sleep fix, actual):8  │             0.0000 mjw/run│            50.0000 mnw/run│       27043467.0000 ns/run│
╰─────────────────────────────────────────────────┴───────────────────────────┴───────────────────────────┴───────────────────────────╯

╭────────────────────────────────────────┬───────────────────────────┬───────────────────────────┬───────────────────────────╮
│name                                    │  major-allocated          │  minor-allocated          │  monotonic-clock          │
├────────────────────────────────────────┼───────────────────────────┼───────────────────────────┼───────────────────────────┤
│  concurrent authenticate (no reuse):8  │             0.0000 mjw/run│            50.0000 mnw/run│     1029831372.0000 ns/run│
╰────────────────────────────────────────┴───────────────────────────┴───────────────────────────┴───────────────────────────╯
```

Without this fix using 2 threads to perform PAM authentication would result in a 38x slowdown compared to using no threads at all (which is what XAPI currently does).

Signed-off-by: Edwin Török <edwin.torok@cloud.com>
edwintorok pushed a commit to edwintorok/xen-api that referenced this pull request Jan 22, 2024
@mseri @robhoes
add semaphore implementation (xapi-project#17)
6d6229b 
The semaphore is used in `xcp-networkd` to limit the number of
concurrent executions of a command (CA-225272).

Signed-off-by: Marcello Seri <marcello.seri@citrix.com>
edwintorok pushed a commit to edwintorok/xen-api that referenced this pull request Jan 22, 2024
@mseri
Merge pull request xapi-project#17 from mseri/ppx
c30fd92 
Remove dependency on camlp4, port to ppx
edwintorok pushed a commit to edwintorok/xen-api that referenced this pull request Jan 22, 2024
Merge pull request xapi-project#17 from xapi-project/nourl
82313e8 
maintenance: clean up opam metadata
edwintorok pushed a commit to edwintorok/xen-api that referenced this pull request Sep 24, 2024
@lindig
Merge pull request xapi-project#17 from lindig/master
9e5aa46 
Simplify jbuild, quiet warnings
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