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: X-Spam-Status: No, score=-4.0 required=3.0 tests=ALL_TRUSTED,BAYES_00 shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from localhost (dcvr.yhbt.net [127.0.0.1]) by dcvr.yhbt.net (Postfix) with ESMTP id B06DF1F463; Wed, 11 Sep 2019 02:22:15 +0000 (UTC) Date: Wed, 11 Sep 2019 02:22:15 +0000 From: Eric Wong To: Konstantin Ryabitsev Cc: meta@public-inbox.org Subject: httpd 502s [was: trying to figure out 100% CPU usage in nntpd...] Message-ID: <20190911022215.GA309@dcvr> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190910181224.urhyoo6av7mhjs67@dcvr> List-Id: 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...