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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90972C433DB for ; Thu, 4 Mar 2021 20:59:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DED964F69 for ; Thu, 4 Mar 2021 20:59:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236743AbhCDU7F (ORCPT ); Thu, 4 Mar 2021 15:59:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236210AbhCDU67 (ORCPT ); Thu, 4 Mar 2021 15:58:59 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4BA9C061574 for ; Thu, 4 Mar 2021 12:58:19 -0800 (PST) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1614891498; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=okpZzFCE+S/kjR2YiW6a2eXyNqNPc4VWZ1UoZTdt4R0=; b=euDRZRTeUVy0kkR2YRYIz8iu3IYbbMcaRDR7Fw0721nXYFm6ZH0QHJRyc7ksYZQIbuN0Vl NXs2UiiLx6p99lTTjd04Ss/YGagIPE+rByGqpUDHQBNRJNKqh7asfr8fbsbxTCovV2CyzX aF6PL1S74HIxampQ2tqbdSgcaaBOWOt+vsUeB6vHxGvz/F/fRNjkUeDRn0mBzNmpn/jG4w Jbp1jWzuanSBkavga1QU8TckKmekOUa7/GChmD64yFV2+N8S0ZAQJnQ8J8zgaP+89SNWws ffizAqVy2N6Ml3ubX2oJwgKXoiR0aZSvUW+hsJdyC+7rq0zciT+38YbdEzYw2A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1614891498; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=okpZzFCE+S/kjR2YiW6a2eXyNqNPc4VWZ1UoZTdt4R0=; b=zKrAHtGAZ+33kwzte2cezMBQ5pox4xJC9EqlZyyqRztMcSOw54Sc8E80MZOEArz0jtEkQP vkHFdD0YjmSYFEBA== To: "Eric W. Biederman" Cc: Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org, Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Oleg Nesterov , Matt Fleming Subject: Re: [PATCH] signal: Allow RT tasks to cache one sigqueue struct In-Reply-To: References: <20210303142025.wbbt2nnr6dtgwjfi@linutronix.de> <20210304081142.digtkddajkadwwq5@linutronix.de> <87tupr55ea.fsf@nanos.tec.linutronix.de> Date: Thu, 04 Mar 2021 21:58:17 +0100 Message-ID: <87lfb263h2.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 04 2021 at 13:04, Eric W. Biederman wrote: > Thomas Gleixner writes: >> >> We could of course do the caching unconditionally for all tasks. > > Is there any advantage to only doing this for realtime tasks? It was mostly to avoid tons of cached entries hanging around all over the place. So I limited it to the case which the RT users deeply cared about. Also related to the accounting question below. > If not it probably makes sense to do the caching for all tasks. > > I am wondering if we want to count the cached sigqueue structure to the > users rt signal rlimit? That makes some sense, but that's a user visible change as a single signal will up the count for a tasks lifetime while today it is removed from accounting again once the signal is delivered. So that needs some thought. Thanks, tglx