PR28708 debuginfod testsuite
Commit Message
Hi -
Planning to commit this shortly.
commit e646e363e72e06e0ed5574c929236d815ddcbbaf (HEAD -> master)
Author: Frank Ch. Eigler <fche@redhat.com>
Date: Sun Apr 3 12:47:17 2022 -0400
PR28708: debuginfod: use MHD_USE_EPOLL for microhttpd threads
Testing on s390x and other architectures indicates that this
configuration reduces thundering-herd wakeups and saturation of a
small number of threads. The run-debuginfod-webapi-concurrency.sh
test appears solid now.
Signed-off-by: Frank Ch. Eigler <fche@redhat.com>
Comments
Hi Frank,
On Sun, Apr 03, 2022 at 01:01:14PM -0400, Frank Ch. Eigler via Elfutils-devel wrote:
> Planning to commit this shortly.
Yes, please!
> commit e646e363e72e06e0ed5574c929236d815ddcbbaf (HEAD -> master)
> Author: Frank Ch. Eigler <fche@redhat.com>
> Date: Sun Apr 3 12:47:17 2022 -0400
>
> PR28708: debuginfod: use MHD_USE_EPOLL for microhttpd threads
>
> Testing on s390x and other architectures indicates that this
> configuration reduces thundering-herd wakeups and saturation of a
> small number of threads. The run-debuginfod-webapi-concurrency.sh
> test appears solid now.
Thanks for digging into this and finding a solution. Nice that it is
just adding that flag. It was driving me nuts that I didn't understand
where the failures really came from. I assume otherwise libmicrohttpd
uses select and it runs into trouble because that can only support up
to 1024 connections simultaniously.
Cheers,
Mark
@@ -1,3 +1,8 @@
+2022-04-03 Frank Ch. Eigler <fche@redhat.com>
+
+ * debuginfod.cxx (main): Use MHD_USE_EPOLL for libmicrohttpd, to
+ encourage more round-robin dispatch of incoming connections.
+
2021-12-09 Alexander Kanavin <alex@linutronix.de>
* debuginfod-client.c (cache_clean_default_interval_s): Change type to
@@ -3880,6 +3880,9 @@ main (int argc, char *argv[])
| MHD_USE_INTERNAL_POLLING_THREAD
#else
| MHD_USE_SELECT_INTERNALLY
+#endif
+#ifdef MHD_USE_EPOLL
+ | MHD_USE_EPOLL
#endif
| MHD_USE_DEBUG, /* report errors to stderr */
http_port,
@@ -3894,6 +3897,9 @@ main (int argc, char *argv[])
| MHD_USE_INTERNAL_POLLING_THREAD
#else
| MHD_USE_SELECT_INTERNALLY
+#endif
+#ifdef MHD_USE_EPOLL
+ | MHD_USE_EPOLL
#endif
| MHD_USE_IPv6
| MHD_USE_DEBUG, /* report errors to stderr */