Date: Fri, 07 Oct 2022 00:26:51 +0000 From: bugzilla-noreply@freebsd.org To: apache@FreeBSD.org Subject: maintainer-feedback requested: [Bug 266873] www/apache24: creating forked processes at 100% CPU spinning in sched_yield() Message-ID: <bug-266873-16115-9MS5xtFyrb@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-266873-16115@https.bugs.freebsd.org/bugzilla/> References: <bug-266873-16115@https.bugs.freebsd.org/bugzilla/>
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Bugzilla Automation <bugzilla@FreeBSD.org> has asked freebsd-apache (Nobody) <apache@FreeBSD.org> for maintainer-feedback: Bug 266873: www/apache24: creating forked processes at 100% CPU spinning in sched_yield() https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D266873 --- Description --- Apache version: apache24-2.4.54 - build with poudriere FreeBSD: 12.3-STABLE FreeBSD 12.3-STABLE stable/12-3a9e60169ee GENERIC amd64 Since updating OS and apache a couple of weeks ago, I have noticed that my system is getting filled up with httpd processes consuming 100% CPU.=20 Here is an example with one rogue process, but after a day of running the system will be eventually full of httpd processes spinning at 100%.=20 root 9947 100.0 0.0 207000 41380 - RJ 10:59 18:42.98 /usr/local/sbin/httpd -DNOHTTPACCEPT www 10243 1.4 0.1 310180 138488 - SJ 11:17 0:01.44 /usr/local/sbin/httpd -DNOHTTPACCEPT www 10059 0.4 0.1 242068 71156 - SJ 11:06 0:03.63 /usr/local/sbin/httpd -DNOHTTPACCEPT root 9738 0.0 0.0 207000 41388 - SsJ 10:37 0:00.35 /usr/local/sbin/httpd -DNOHTTPACCEPT www 9853 0.0 0.1 244096 70872 - SJ 10:47 0:06.49 /usr/local/sbin/httpd -DNOHTTPACCEPT www 9887 0.0 0.1 242500 69808 - IJ 10:51 0:08.48 /usr/local/sbin/httpd -DNOHTTPACCEPT www 10058 0.0 0.1 307876 136996 - IJ 11:06 0:04.76 /usr/local/sbin/httpd -DNOHTTPACCEPT www 10136 0.0 0.1 242592 71452 - IJ 11:12 0:02.50 /usr/local/sbin/httpd -DNOHTTPACCEPT www 10144 0.0 0.1 244644 71328 - IJ 11:14 0:01.31 /usr/local/sbin/httpd -DNOHTTPACCEPT www 10166 0.0 0.1 244648 73028 - SJ 11:15 0:00.99 /usr/local/sbin/httpd -DNOHTTPACCEPT www 10239 0.0 0.1 209800 61568 - IJ 11:16 0:00.20 /usr/local/sbin/httpd -DNOHTTPACCEPT Usual behavior with prefork will be an initial process running as root, whi= ch then forks additional processes and sets them to run as www user. What appe= ars to be happening here is that when the fork occurs, something gets stuck bef= ore it is able to switch to www.=20 In the case of the rogue process above, output of truss -p 9947 is simply a continuous loop of: sched_yield() =3D 0 (0x0) For some extra context, I am running this inside a jail, hosting nextcloud = with mod_php80, mysql, redis. None of my other web apps are having this issue bu= t it could be something which only appears under load and nextcloud is certainly= the heaviest application here.=20 Also, I tried switching over to php-fpm with mpm_event and the same issue w= as encountered there, so it certainly feels like something core to apache's forking code at play here.
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