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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 743F6C77B7F for ; Wed, 17 May 2023 11:47:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D62DA900004; Wed, 17 May 2023 07:47:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D1292900003; Wed, 17 May 2023 07:47:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C0220900004; Wed, 17 May 2023 07:47:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id B13B0900003 for ; Wed, 17 May 2023 07:47:22 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 39EFDC050D for ; Wed, 17 May 2023 11:47:22 +0000 (UTC) X-FDA: 80799571524.21.27D4576 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf16.hostedemail.com (Postfix) with ESMTP id 563A718000E for ; Wed, 17 May 2023 11:47:19 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=esGUpT5g; dkim=pass header.d=linutronix.de header.s=2020e header.b=yAz8IVxy; spf=pass (imf16.hostedemail.com: domain of tglx@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=tglx@linutronix.de; dmarc=pass (policy=none) header.from=linutronix.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1684324039; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=6KIyu3sebF6GHU6/B6dNKtlwIbcgHls7NAh3EXRrdqM=; b=2UNZUAm+4X5xnH9DSOuvzu6i9xhhdmV6MTqkQmHd8D2qIZWS4teevRLpf50oiM3LahKtdN RvTliZISt5QzXrlhPIltL5VXL7zxBgAzmIGT1lnx7zuGgx/gnM5N+JaGOfm5Xgl2jjdftJ DP/PGdNxlvKbgFA7tM7BuhNLdM4R29A= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1684324039; a=rsa-sha256; cv=none; b=t+0f8hB9EMZd24HMqZXj0nr/141oGQg2w/M6fEkS4/rjlHw/sTCr+NSNLbg4Om+BXqCXcI SFTkxLWXrr+bNDJvEjAcWWF/jn2XE1Ac6oObR2dEraMp6XdSh+LgUeg8Ic3TLBpJtFyjxn ClWlBlSp4tS1z4KUskPsAiZcGlzCssw= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=esGUpT5g; dkim=pass header.d=linutronix.de header.s=2020e header.b=yAz8IVxy; spf=pass (imf16.hostedemail.com: domain of tglx@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=tglx@linutronix.de; dmarc=pass (policy=none) header.from=linutronix.de From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1684324036; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6KIyu3sebF6GHU6/B6dNKtlwIbcgHls7NAh3EXRrdqM=; b=esGUpT5gxuV0hfmDkOSPsohN+4wFy7nB0y1gCnyZvMSqFRSaGA/d6W5h46I+WwyxZtikqj 11E8lrMjBcv8mFyWyNcT+nJf554Whk950VkLgf14i34fihjCLOJLI18QaBnJAGqtdLSbzV uf36U04Y1k7kbExF9sOF7OzY3a6e9OyDv3SnzhuSdEyuAN13Ixuzvi48GhQNyXRPvYj7dj J4iNfm0q+8RRdvLNTWEwxeCIReDUKyU4nds+9e2ckzqq/KATacFAUqapYq0Od4C/Q3akW6 oLUZcmH8JPznKMb3bBPpUA8HtjeM+98o4pcrc+3NLwBB7ZuxiASQ6WCG5EOLkQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1684324036; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6KIyu3sebF6GHU6/B6dNKtlwIbcgHls7NAh3EXRrdqM=; b=yAz8IVxyB/xrPpN19ZLCp6MdFpQ+1G8ZPCHGTkEfwZTG4EtmVStyTgjvwzBarkQd1OQuMJ OV31pckeHkVSPtDA== To: Nadav Amit Cc: Uladzislau Rezki , "Russell King (Oracle)" , Andrew Morton , linux-mm , Christoph Hellwig , Lorenzo Stoakes , Peter Zijlstra , Baoquan He , John Ogness , linux-arm-kernel@lists.infradead.org, Mark Rutland , Marc Zyngier , x86@kernel.org Subject: Re: Excessive TLB flush ranges In-Reply-To: <87ttwb5jx3.ffs@tglx> References: <87a5y5a6kj.ffs@tglx> <87353x9y3l.ffs@tglx> <87zg658fla.ffs@tglx> <87r0rg93z5.ffs@tglx> <87cz308y3s.ffs@tglx> <87y1lo7a0z.ffs@tglx> <87o7mk733x.ffs@tglx> <7ED917BC-420F-47D4-8956-8984205A75F0@gmail.com> <87bkik6pin.ffs@tglx> <87353v7qms.ffs@tglx> <87ttwb5jx3.ffs@tglx> Date: Wed, 17 May 2023 13:47:16 +0200 Message-ID: <87r0rf5ge3.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 563A718000E X-Stat-Signature: b9ptxgyf69u1frctrhxrjgif3t5whtoh X-Rspam-User: X-Rspamd-Server: rspam09 X-HE-Tag: 1684324039-451207 X-HE-Meta: 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 duwe1hDq 1oP5zzvsJu5akkz3ikdSzOA2WePVmAQOCrRSjHCsMFKg41QpiF46cKZQumzOgx7p21PxEndN4LeLeVBY1IarSnDGD6ffOYn/ZkphbFZBckrx/cs9yAU3i8FSBE3k0OS/1uTKbCnV/P3NHYSLDveOn8dz2HYsJyT5wra3X X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, May 17 2023 at 12:31, Thomas Gleixner wrote: > On Tue, May 16 2023 at 18:23, Nadav Amit wrote: >>> INVLPG is not serializing so the CPU can pull in the next required cache >>> line(s) on the VA list during that. >> >> Indeed, but ChatGPT says (yes, I see you making fun of me already): >> =E2=80=9Chowever, this doesn't mean INVLPG has no impact on the pipeline= . INVLPG >> can cause a pipeline stall because the TLB entry invalidation must be >> completed before subsequent instructions that might rely on the TLB can >> be executed correctly.=E2=80=9D >> >> So I am not sure that your claim is exactly correct. > > Key is a subsequent instruction which might depend on the to be flushed > TLB entry. That's obvious, but I'm having a hard time to construct that > dependent intruction in this case. But obviously a full TLB flush _is_ guaranteed to stall the pipeline, right?