From mboxrd@z Thu Jan 1 00:00:00 1970 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. From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id ABDADC433EF for ; Mon, 3 Jan 2022 18:50:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=XLK9I2T7okq0NdWDGbhSFyJ3Z6RfGbD/A0mJKRfyCZQ=; b=z51L9c3lQqc547 jHGJ4aJWLqCh3yhptdq4m5i23hjBhsNI5B3JOcOM2/GwbVRTwJbkFbs2zKVwSd3HJX/YA5fJfC01o mjvARvmbT6H7G3Udt16VN7hM+kEoLku7ViYAnWeiveLYNXRhBjv70Y7V/r7iG5WXXTF7nt802u8FV YTlLpkXuBJpda7EyalkPrWwoRRWNIckbQg8PhO0HT8W57cfrzJIneKhVDBc+resbJl82kHR8RuTxO lwKR38FSnvpycd9UGDrR52ykwLy8jfic5QWD6e0o/wmP3fmlmJcefngxdRXeg+vhl7Px6mrpGpK5E OW5tNEe4hPWCDRGDht9Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n4SOm-009rs0-KZ; Mon, 03 Jan 2022 18:49:36 +0000 Received: from zeniv-ca.linux.org.uk ([2607:5300:60:148a::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n4SOk-009rqx-0t for linux-mtd@lists.infradead.org; Mon, 03 Jan 2022 18:49:35 +0000 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-Disposition: inline In-Reply-To: <20220103181956.983342-1-walt@drummond.us> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220103_104934_073209_2E04DC10 X-CRM114-Status: GOOD ( 11.38 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org T24gTW9uLCBKYW4gMDMsIDIwMjIgYXQgMTA6MTk6NDhBTSAtMDgwMCwgV2FsdCBEcnVtbW9uZCB3 cm90ZToKPiBUaGlzIHBhdGNoIHNldCBleHBhbmRzIHRoZSBudW1iZXIgb2Ygc2lnbmFscyBpbiBM aW51eCBiZXlvbmQgdGhlCj4gY3VycmVudCBjYXAgb2YgNjQuICBJdCBzZXRzIGEgbmV3IGNhcCBh dCB0aGUgc29tZXdoYXQgYXJiaXRyYXJ5IGxpbWl0Cj4gb2YgMTAyNCBzaWduYWxzLCBib3RoIGJl Y2F1c2UgaXTigJlzIHdoYXQgR0xpYmMgYW5kIE1VU0wgc3VwcG9ydCBhbmQKPiBiZWNhdXNlIG1h bnkgYXJjaGl0ZWN0dXJlcyBwYWQgc2lnc2V0X3Qgb3IgdWNvbnRleHRfdCBpbiB0aGUga2VybmVs IHRvCj4gdGhpcyBjYXAuICBUaGlzIGxpbWl0IGlzIG5vdCBmaXhlZCBhbmQgY2FuIGJlIGZ1cnRo ZXIgZXhwYW5kZWQgd2l0aGluCj4gcmVhc29uLgoKQ291bGQgeW91IGV4cGxhaW4gdGhlIHBvaW50 IG9mIHRoZSBlbnRpcmUgZXhlcmNpc2U/ICBXaHkgZG8gd2UgbmVlZCBtb3JlCnJ0IHNpZ25hbHMg aW4gdGhlIGZpcnN0IHBsYWNlPwoKZ2xpYmMgaGFzIHF1aXRlIGEgYml0IG9mIHV0dGVybHkgcG9p bnRsZXNzIGZ1dHVyZS1wcm9vZmluZy4gIFNvICJ0aGV5CmFsbG93IG1vcmUiIGlzIG5vdCBhIGdv b2QgcmVhc29uIC0gbm90IHdpdGhvdXQgYSBwbGF1c2libGUgdXNlLWNhc2UsCmF0IGxlYXN0LgoK X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCkxp bnV4IE1URCBkaXNjdXNzaW9uIG1haWxpbmcgbGlzdApodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9y Zy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LW10ZC8K From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: Re: [RFC PATCH 0/8] signals: Support more than 64 signals Date: Mon, 3 Jan 2022 18:48:09 +0000 Message-ID: References: <20220103181956.983342-1-walt@drummond.us> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <20220103181956.983342-1-walt@drummond.us> Sender: Al Viro List-ID: Content-Type: text/plain; charset="windows-1252" 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@linu 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=E2=80=99s 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.