From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 530EA31A567; Tue, 26 Aug 2025 16:27:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756225650; cv=none; b=QpdlYYoMLoEtlG1MfSTfASDw4MLoD+Slqf6sCLfch+y+mBw8HJIrH1d/vrshiKqRjidICJXhCOxazKGdEA5ykKxQf+wHMWXf8id3gVB15UYy0adcLn9mEe+9QU1/bellHWKSKipZ+Tgny6KnpBRYNUGTTkCbwHCjGA6XUnhmwkw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756225650; c=relaxed/simple; bh=U5i6Ai9CYUMbdmoeMp+ZUqbk8vq+WFrcMy7YrJP1WM8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iRglG8yvj18x6G9XfU81gBsdcWoA90H9o8JomN85KiQOq1/7C/pDt28JT3fITusiSmNhofJHVWZzYOwRKKOjFyl3DJu+EvlbuuUSYQyVs7LGERRLtqaT/C3xqzdw6ruu9Xb66CeBJoLSHN5HdhMLBC2p7es+O6YMjkct3KJc7pw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JuHX962y; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JuHX962y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D2B3C4CEF1; Tue, 26 Aug 2025 16:27:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756225649; bh=U5i6Ai9CYUMbdmoeMp+ZUqbk8vq+WFrcMy7YrJP1WM8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JuHX962ycdqh+pGgK05dllJQ9dS8EFFkt/XJrQFGHNVpHwRwMJ4Ys8DEnGl10VFs6 R2UX0zzQN1hcCozXsJbo1ZFDcisjIi3IMCmz0brUYcBts2ydPlW9xS0IgRMrYo1AEw 6TxSlOK7gAo1ES5r1wTDdKnH4HuB3airDCoXIA/zIR8e9hE7Kj7oYHyjRPQsu21eRc t/N46x7bz23QvTyMAiQWyPkCBb5VzpRqCeFMhAmQxx7l4j5/wT0q43D7PMUlm2Cwco m/MG5ntCP9cgDI/xOMpkeR22tUm772CxdHy8ekRUx71/g0E+hywe/nJ9xKM6IIBnLy 2xMN+TChm6a8w== Date: Tue, 26 Aug 2025 06:27:27 -1000 From: Tejun Heo To: Sebastian Andrzej Siewior Cc: linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, Lai Jiangshan , Ingo Molnar , Peter Zijlstra , Steven Rostedt , Thomas Gleixner Subject: Re: [PATCH] softirq: Provide a handshake for canceling tasklets via polling on PREEMPT_RT Message-ID: References: <20250819150105.DYeV89fa@linutronix.de> <20250820103657.vDuDuLx6@linutronix.de> <20250820105518.Yf36NzJd@linutronix.de> <20250821092827.zcFpdnNy@linutronix.de> <20250822094812.L4hiquhY@linutronix.de> <20250826154942.BcGs2_U5@linutronix.de> 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: <20250826154942.BcGs2_U5@linutronix.de> Hello, On Tue, Aug 26, 2025 at 05:49:42PM +0200, Sebastian Andrzej Siewior wrote: > On 2025-08-22 08:07:47 [-1000], Tejun Heo wrote: > > Hello, Sebastian. > Hi Tejun, > > > Agreed, once we get rid of them, we can drop the whole block for both RT and > > !RT - ie. revert the patch that added it. But, wouldn't it be more orderly > > to match the semantics in both cases even if the behavior isn't quite > > optimal? We can put some comment noting what to do once the culprits are > > updated to not need it. > > Sure. I am only worried that if something is possible, people will use > it. I don't think things will change if we debate for another week ;) > The first patch here in this thread should provide the symmetrical API. > > Oh. We could also hide this polling API behind a special API which is > hidden just for three special cases so everyone else would do the right > job. Oh yeah, that makes a lot of sense to me - splitting it out into something which is named explicitly to discourage further usages. Thanks. -- tejun