From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS3215 2.6.0.0/16 X-Spam-Status: No, score=-3.3 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from mail-qk1-x744.google.com (mail-qk1-x744.google.com [IPv6:2607:f8b0:4864:20::744]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id A683F1F463 for ; Wed, 11 Sep 2019 10:24:44 +0000 (UTC) Received: by mail-qk1-x744.google.com with SMTP id q203so20263880qke.1 for ; Wed, 11 Sep 2019 03:24:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=google; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-disposition:in-reply-to:user-agent; bh=7CFz/2fCmHhm/qku1Bjw0wNsyKOjKM/Hy7YfF/jb6rU=; b=PKF3n2IawKMivIMr3N8baIwybF9xlb+s5LQu6ijnoSe7YMoWTw5yYD++/S66ollkG2 z09YO9mJGj0Hr7NhrVndiOJIcjSYmacEttqU7NuDzefMsmlZ7r3/ztd2niOMqetG0u+r CrkzZwjEapJXRpuImDsUr6nFICwOZagJMXgaE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :in-reply-to:user-agent; bh=7CFz/2fCmHhm/qku1Bjw0wNsyKOjKM/Hy7YfF/jb6rU=; b=DMn860UPdiOwBmjeazj4C9HoopC8rQ6lp+tazfYy21JUO94DUf/MULU/dCyFZDfHzY VEuwDs/MA9HazKczHi3ifbZi2WO8YKPQIaM9d8zmk3LInMDt9+URZKptM3bjsJ3kx0iC T2mTqtYxoMd48VEHivuGrXOtfBbeXnYotBBLsjoiDbpTx43jsa5vikygPvQ6tckv7gnp YPXG3LjPhGZ7UZ1Dv0rXJo/X4nU4kBL1YvjFbLIdJwiY03pxjtSUhvPYQH8KJV6ruy8E SS8sSe/Z2kiSGsCVrhAAl3+y3GJWnKdhUEC2QMFskjOtate5iqnH8XF4bqqDnlDwZIEB UviQ== X-Gm-Message-State: APjAAAU8LTa3b05OyVajUBjexpr8EY2WpK28p6UbEZtNOAULFg0BtrKx 2Culh130oht66ZLa0EeR42etqg== X-Google-Smtp-Source: APXvYqyMO77/VqmSkDFAQggjra01w00LWHKf54RH+GtPyu9c0L6NEdHmJWkkl4OfEAxxo+3lgIWmyQ== X-Received: by 2002:a37:5f87:: with SMTP id t129mr34941148qkb.183.1568197483496; Wed, 11 Sep 2019 03:24:43 -0700 (PDT) Received: from pure.paranoia.local ([87.101.92.157]) by smtp.gmail.com with ESMTPSA id 64sm10774154qkk.63.2019.09.11.03.24.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Sep 2019 03:24:42 -0700 (PDT) Date: Wed, 11 Sep 2019 06:24:36 -0400 From: Konstantin Ryabitsev To: Eric Wong Cc: meta@public-inbox.org Subject: Re: httpd 502s [was: trying to figure out 100% CPU usage in nntpd...] Message-ID: <20190911102436.GA21959@pure.paranoia.local> Mail-Followup-To: Eric Wong , meta@public-inbox.org References: <20190908104518.11919-1-e@80x24.org> <20190908105243.GA15983@dcvr> <20190909100500.GA9452@pure.paranoia.local> <20190909175340.u5aq4ztfzukko7zb@dcvr> <20190910083820.GA8018@pure.paranoia.local> <20190910181224.urhyoo6av7mhjs67@dcvr> <20190911022215.GA309@dcvr> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190911022215.GA309@dcvr> User-Agent: Mutt/1.12.1 (2019-06-15) List-Id: On Wed, Sep 11, 2019 at 02:22:15AM +0000, Eric Wong wrote: > Btw, some of the changes in public-inbox to use EPOLLET / > EPOLLONESHOT would make it more sensitive to kernel bugs, > and missed wakeups could cause resource exhaustion... > > I just noticed this now: > https://lore.kernel.org/lkml/20190904175303.918854334@linuxfoundation.org/ > > And I remember I found another mm-compaction-related issue > several years back (early 3.x) which caused epoll wakeups to be > missed... To give some more data points, downgrading to f4f0a3be still shows a number of /tmp/PerlIO* (deleted) entries, but the number of pipes stays the same over time. If I switch to the latest master, the number of broken pipes grows steadily following each git pull (in the hundreds after 10 minutes of running). I've downgraded lore.kernel.org to f4f0a3be for now to avoid the resource exhaustion. -K