Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

OVS 2011-02-14 #18

Merged
4 commits merged into from
Feb 14, 2011
Merged

OVS 2011-02-14 #18

4 commits merged into from
Feb 14, 2011

Conversation

dcurran
Copy link

@dcurran dcurran commented Feb 14, 2011

OVS integration changes (2011-02-14).

[I posted these same 4 patches earlier today to xen-api@lists.xensource.com list].

blp and others added 4 commits February 14, 2011 15:58
This fixes the converse of the problem addressed by commit fe19e820
"xenserver: Kill bond master's dhclient when bringing up bond slave".  In
that commit's log message, I claimed that the converse was not a problem,
but I was wrong.  I must have screwed up in testing, because it really is
a problem.  This commit fixes it.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
CC: Dominic Curran <dominic.curran@citrix.com>
Reported-by: Michael Mao <mmao@nicira.com>
Bug xapi-project#2668.
This patch defensively guarantees that the first id in
xs-network-uuids will belong to the primary network (as opposed to
a vlan).  Given that the primary network id comes first, it parses
xs-network-ids and only copies the primary id to bridge-id when
monitor-external-ids is run.

Feature xapi-project#3647

Signed-off-by: Ethan Jackson <ethan@nicira.com>
Reviewed-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Dominic Curran <dominic.curran@citrix.com>
This commit adds bond_mode configuration to Interface Reconfigure
so that it may be changed using standard XenServer commands.

Signed-off-by: Ethan Jackson <ethan@nicira.com>
Signed-off-by: Dominic Curran <dominic.curran@citrix.com>
This commit makes necessary changes to Interface Reconfigure to
allow miimon bond-detect-mode and bond-miimon-interval to be
changed using xapi.

Signed-off-by: Ethan Jackson <ethan@nicira.com>
Signed-off-by: Dominic Curran <dominic.curran@citrix.com>
johnelse pushed a commit to johnelse/xen-api that referenced this pull request Apr 8, 2015
…bugfix

CA-166087: Bump xencenter_max_verstring to 2.4
koushikcgit pushed a commit to koushikcgit/xen-api that referenced this pull request Aug 7, 2015
The script needs to find the vif metadata, which is stored
in a different directory for each xenopsd backend. We plumb through
the name of the backend so the script can find it.

With this change, the interface is properly brought up and
port-locking rules activated.

Fixes xapi-project#18

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
taoyongd pushed a commit to taoyongd/xen-api that referenced this pull request Jun 27, 2017
Fix http header parsing and add unit test
kc284 added a commit to kc284/xen-api that referenced this pull request Mar 11, 2021
robhoes pushed a commit to robhoes/xen-api that referenced this pull request Jul 6, 2021
robhoes pushed a commit that referenced this pull request Sep 14, 2021
robhoes pushed a commit that referenced this pull request Sep 14, 2021
travis: switch to new opam 1.2.0 pin based workflow
robhoes pushed a commit that referenced this pull request Sep 14, 2021
CA-179295: Fix for xcp-rrdd spinning
psafont pushed a commit to psafont/xen-api that referenced this pull request Sep 20, 2021
Add opam and travis; Oasis now autogenerated
robhoes pushed a commit to robhoes/xen-api that referenced this pull request Sep 21, 2021
Update to new cohttp.0.15.2 interfaces
psafont pushed a commit to psafont/xen-api that referenced this pull request Oct 19, 2021
CA-116420: when creating linux bond, add MAC address after adding bond slaves
lindig pushed a commit to lindig/xen-api that referenced this pull request Nov 9, 2021
src/io: make safe-string compliant
robhoes pushed a commit to robhoes/xen-api that referenced this pull request Jan 10, 2022
robhoes added a commit to robhoes/xen-api that referenced this pull request Jan 10, 2022
Merge first part of CBT feature branch into master
psafont pushed a commit to psafont/xen-api that referenced this pull request Mar 17, 2023
edwintorok added a commit to edwintorok/xen-api that referenced this pull request Oct 10, 2023
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
edwintorok pushed a commit to edwintorok/xen-api that referenced this pull request Jan 22, 2024
edwintorok pushed a commit to edwintorok/xen-api that referenced this pull request Jan 22, 2024
edwintorok added a commit to edwintorok/xen-api that referenced this pull request Sep 24, 2024
Move to dune and update opam dependencies
This pull request was closed.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

3 participants