From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 22349 invoked from network); 28 Jan 2021 10:08:46 -0000 Received: from alyss.skarnet.org (95.142.172.232) by inbox.vuxu.org with ESMTPUTF8; 28 Jan 2021 10:08:46 -0000 Received: (qmail 9710 invoked by uid 89); 28 Jan 2021 10:09:09 -0000 Mailing-List: contact supervision-help@list.skarnet.org; run by ezmlm Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Received: (qmail 9703 invoked from network); 28 Jan 2021 10:09:09 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:subject:message-id:mail-followup-to:mime-version :content-disposition; bh=G2lr87fQSbnMtVqHatl4aT0eeILdkihixGbJNzlUyeE=; b=eakN5ygNzh1jxP6tP7Tjkp+t2CWzuP/gQ1Vdb6kQVjl5U9jZWMKU2CPiQkCkvMMWVj BvVEALgDcKgP0Pcle7MIA71hJf2aPx5TGczNvE7wG9EQGhYTPvY0tbsLddWjLW/wmsdv XSiAktZAMy9HjSjfKO66cwcImKRgw/oxdwhchNxPl1BUkJdmr5Oigoi0W3DnecREckdl 6vtr7i2xkhawkVxLDPc5EOditn0sAuLHWmKGiiwWf7BvIIFP2SKJ5TD3oa1xZactaeMc m/y/n8w850yN4BIB3IGI8N90RQh7fbASMEfY3qLHdROX/pPELwTJBcj/FIn30kLYWuN5 vEUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:subject:message-id:mail-followup-to :mime-version:content-disposition; bh=G2lr87fQSbnMtVqHatl4aT0eeILdkihixGbJNzlUyeE=; b=rkh1GnQdUubjy4NNP5Mjgb+QUAeEaGi0Ym7VsPCAm/MfT5Nx6Nfi9ghmT5R4Nhk4Nj orlQpjs3Cbrg9gi3J9NDlMJ0/u0SKHgzWnnl+4o80QhQuVdPUo5eNTw2yDeEdOl7iSWZ Ti1CP4Wr5/cvp42gMUu6MUA8Aim3Qy5FGDF2VTXtofPGP0de2SmBMemibuIOVy8Fxbge M5N4N+cX8QqcFyRcfMpAS0HGCIZ6RoUtGENC0HaJSfDb9jxhXPp+yHghMGVBoYpywFhv DNmJh5IxIOtzZoZUYLTQ30fp5mMGwoeXUO3vD2LxlY6QEhA60DfDSELgtQhB3yUJx4Zt GYpw== X-Gm-Message-State: AOAM533BTRfKFTc5/sxTYrkxtJyiRJKv939K9MPf/j0e9O4uPEStV8mr vawJxPRVmU48iq4HrsG7P0Sy5R9xzcY= X-Google-Smtp-Source: ABdhPJxoLx1M9dh0qMYOe7UGuenRW8VQaT8WRPJhI1nzZ1LTYrZregogRPAdoZ7ygflBxMxko7Jz6g== X-Received: by 2002:a17:907:9f9:: with SMTP id ce25mr10968006ejc.352.1611828521653; Thu, 28 Jan 2021 02:08:41 -0800 (PST) From: "Casper Ti. Vector" X-Google-Original-From: "Casper Ti. Vector" Date: Thu, 28 Jan 2021 18:08:36 +0800 To: supervision@list.skarnet.org Subject: Some suggestions on old-fashioned usage with s6 2.10.x Message-ID: Mail-Followup-To: supervision@list.skarnet.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline I did not actively follow the recent evolution of s6, and have just been bitten badly by s6 2.10.x on my Alpine servers (where slew [1] is used of course) when it comes along with other updates. [1] First, kernel panic on booting. With some tentative echo(1) invocations (with I/O redirections to /dev/console when necessary) and messing with console resolution (so I could see the outputs before the panic), I found the problem occurred with `s6-svscan' exiting because of the legacy `-s' option in [2]. The fix itself is trivial, but it would be better if we kept the option supported for a transition period, and that only removed it from the manual pages while urging users to get rid of it. After all, in this case, silently ignoring `-s' is behaviourly similar to (if not perfectly compatible with) old `s6-svscan'. [2] Second, `s6-svscan' now waits for its `s6-supervise' children to exit before exec()ing `.s6-svscan/finish', so it hangs forever (save for magic SysRq) due to the catch-all logger on halting. I do know that the recommended way to shut down is to use `s6-linux-init-shutdown', but it will be nice if the old-fashioned way (with stage 1 and stage 3 as static scripts) is supported as well after minimal modifications to both s6 and (for instance) slew. I also understand that `s6-svc -X' has been removed, and that the invocation in [3] would no longer work anyway because [3] is exec()ed by `s6-svscan'. However, I think the following way is practical yet minimal: introduce an option (perhaps still `-X') of `s6-svc', but that tells `s6-supervise' to exit normally *upon receiving SIGTERM or SIGHUP* (this is where the behaviour differs from the old `s6-svc -X') without waiting for the children to exit; then move the `s6-svc -X' invocation from `rc.halt' into `rc.fin' (where `s6-rc -d change all' is also spawn). [3] Any suggestions? -- My current OpenPGP key: RSA4096/0x227E8CAAB7AA186C (expires: 2022.09.20) 7077 7781 B859 5166 AE07 0286 227E 8CAA B7AA 186C