From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A8A5174EFA for ; Wed, 13 Nov 2024 18:50:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731523832; cv=none; b=bHPQM2lU4OyS+1/+OUAhcFr2HvIcVsHG6KaPWXJqG8HAOAZZypCBOClRjszTKA0NqZcLwHfOrXdYX+teiNYfeXaGnGn9CcRaTZMYruYfMwVh6nKWNrOVknM1H0NFg1i07S/d5AgDR4MfaoDMsJNtARrxSik1Fm1TIpOp2V8dmD0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731523832; c=relaxed/simple; bh=mBs5au3OFQRAm6YvuRzSet2qotb/hmlgfsCKASvjb6Q=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ft9sqxX4fcNeUSv0FcXc0y5rlT6ssbrJYAqve9g20iW9zvbUXu/RPm+im87xCBWwzvNcjLtJ/Sdpc85Mz2tWSJ8bl4FD5UVy79jLZ1o45KhTonHAH0uE03EfFbVYOfENX0W9Dpwvm8hVxw0IeTlioc+LucuFQBCZ06prqsmeL10= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=j9SFGYvv; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="j9SFGYvv" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=mBs5au3OFQRAm6YvuRzSet2qotb/hmlgfsCKASvjb6Q=; b=j9SFGYvvVI9W3dkisGXqIcTLCs RPQrQpbA9cjq456QTN9Y6acTvaUDcplQcWBEN7GyWvmAUIuOcv9Buw1XS7mqRFT9hOaSfKGvdAewt OB7suHTnQwk445v+x6hM/C3GfcQZOYKLbKSLb2RVEbGXAODRKBFAXmezOhp6/tSXa5wpT74A5h+l2 XX0Nco/3dskmftMUTS95jbZIxJlIXXs1d3FAHbzLzCMBsgYyx7Wbr7Wq49OS84w/VK9avDSCiFRiH vjokQCy2dV5cpRSecv7wyAEOGnEKyG3Lo4oi84jbweQsdKUPyR16sdoRzuBjvqVhZQJv/oDXRAzRV AC8nWCmA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tBIRU-0000000DNmZ-268e; Wed, 13 Nov 2024 18:50:16 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id ACD70300478; Wed, 13 Nov 2024 19:50:13 +0100 (CET) Date: Wed, 13 Nov 2024 19:50:13 +0100 From: Peter Zijlstra To: Prakash Sangappa Cc: linux-kernel@vger.kernel.org, rostedt@goodmis.org, tglx@linutronix.de, daniel.m.jordan@oracle.com, Mathieu Desnoyers Subject: Re: [RFC PATCH 0/4] Scheduler time slice extension Message-ID: <20241113185013.GA22571@noisy.programming.kicks-ass.net> References: <20241113000126.967713-1-prakash.sangappa@oracle.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241113000126.967713-1-prakash.sangappa@oracle.com> On Wed, Nov 13, 2024 at 12:01:22AM +0000, Prakash Sangappa wrote: > This patch set implements the above mentioned 50us extension time as posted > by Peter. But instead of using restartable sequences as API to set the flag > to request the extension, this patch proposes a new API with use of a per > thread shared structure implementation described below. This shared structure > is accessible in both users pace and kernel. The user thread will set the > flag in this shared structure to request execution time extension. But why -- we already have rseq, glibc uses it by default. Why add yet another thing?