Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19C06C433EF for ; Mon, 3 Jan 2022 18:49:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235882AbiACSte (ORCPT ); Mon, 3 Jan 2022 13:49:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235519AbiACStd (ORCPT ); Mon, 3 Jan 2022 13:49:33 -0500 Received: from zeniv-ca.linux.org.uk (zeniv-ca.linux.org.uk [IPv6:2607:5300:60:148a::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8DE14C061761; Mon, 3 Jan 2022 10:49:32 -0800 (PST) Received: from viro by zeniv-ca.linux.org.uk with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1n4SNN-00Gymw-Sf; Mon, 03 Jan 2022 18:48:10 +0000 Date: Mon, 3 Jan 2022 18:48:09 +0000 From: Al Viro To: Walt Drummond Cc: aacraid@microsemi.com, anna.schumaker@netapp.com, arnd@arndb.de, bsegall@google.com, bp@alien8.de, chuck.lever@oracle.com, bristot@redhat.com, dave.hansen@linux.intel.com, dwmw2@infradead.org, dietmar.eggemann@arm.com, dinguyen@kernel.org, geert@linux-m68k.org, gregkh@linuxfoundation.org, hpa@zytor.com, idryomov@gmail.com, mingo@redhat.com, yzaikin@google.com, ink@jurassic.park.msu.ru, jejb@linux.ibm.com, jmorris@namei.org, bfields@fieldses.org, jlayton@kernel.org, jirislaby@kernel.org, john.johansen@canonical.com, juri.lelli@redhat.com, keescook@chromium.org, mcgrof@kernel.org, martin.petersen@oracle.com, mattst88@gmail.com, mgorman@suse.de, oleg@redhat.com, pbonzini@redhat.com, peterz@infradead.org, rth@twiddle.net, richard@nod.at, serge@hallyn.com, rostedt@goodmis.org, tglx@linutronix.de, trond.myklebust@hammerspace.com, vincent.guittot@linaro.org, x86@kernel.org, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, kvm@vger.kernel.org, linux-alpha@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-m68k@vger.kernel.org, linux-mtd@lists.infradead.org, linux-nfs@vger.kernel.org, linux-scsi@vger.kernel.org, linux-security-module@vger.kernel.org Subject: Re: [RFC PATCH 0/8] signals: Support more than 64 signals Message-ID: References: <20220103181956.983342-1-walt@drummond.us> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220103181956.983342-1-walt@drummond.us> Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 03, 2022 at 10:19:48AM -0800, Walt Drummond wrote: > This patch set expands the number of signals in Linux beyond the > current cap of 64. It sets a new cap at the somewhat arbitrary limit > of 1024 signals, both because it’s what GLibc and MUSL support and > because many architectures pad sigset_t or ucontext_t in the kernel to > this cap. This limit is not fixed and can be further expanded within > reason. Could you explain the point of the entire exercise? Why do we need more rt signals in the first place? glibc has quite a bit of utterly pointless future-proofing. So "they allow more" is not a good reason - not without a plausible use-case, at least.