From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lj1-f179.google.com (mail-lj1-f179.google.com [209.85.208.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 84F802F3A for ; Wed, 4 May 2022 20:40:27 +0000 (UTC) Received: by mail-lj1-f179.google.com with SMTP id s27so3180322ljd.2 for ; Wed, 04 May 2022 13:40:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=n5f7afkXUKTo3IPWzmlyI8gr9ELiri6KDY4jDCLAwqk=; b=hxZbDwh249V8ZWvJvHgV8HOAuCwzitlpmdUaF1aBT2GoF1r95NpNwyDzyBX4DdfW4t S+439ChsQrTcSauZNdL3zxMoiHfb+9og+70XrhkoRCXDijiIGEY4j8RIp1HfceEd4Ycx YfSmJLaV8W0hI8BFv1q8CTPECn1nKJl+L25HM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=n5f7afkXUKTo3IPWzmlyI8gr9ELiri6KDY4jDCLAwqk=; b=kBqdD3AShnIU2aDazFAXcib8O6H2QlurX/dzoetMGgQN+9ve2wX3wn52H5tNhaX3iI 2QkOfKDB2L7mDN0vRoXWazN27ZyUuKMFe77+bTMbmGUMyRSe8y28vOmrEGTXiAQbJ3vM 1uAH7ePn5HYXtWwH8SUnruqrHWyP2gsVAk7vOWqmBdGnupgTUCx0yCKrB/acj4yHIzsz CnZ8tRyNQ3JabEKWeXkFXGh/rE3tWLGZzP7Lo99UbkO+5oqtxILgXXshX5CWsMtJFfJX oKck0xeT6/auNngI52AK2lk8s4Y5KgTTItzXlDOga/mJ1RsY/JENWU3lg2VOC7wuWibr cp/A== X-Gm-Message-State: AOAM5312TvMcVU+KWvYdgazKM15cdjXwoZ+fFgHcPGnnk3GtroPYucIl 3vnalnLeB1s2vp2is/sbwM7lSj9qWkOTd/kEOGs= X-Google-Smtp-Source: ABdhPJwMOPucxvRjs2IQiL2sUZ2EdSynGjxqwXkNRsQETWNBJaAaB2FTe/oP4PTzXBv5Irs1DeE6LQ== X-Received: by 2002:a05:651c:505:b0:24f:5248:3018 with SMTP id o5-20020a05651c050500b0024f52483018mr10461941ljp.45.1651696825181; Wed, 04 May 2022 13:40:25 -0700 (PDT) Received: from mail-lf1-f41.google.com (mail-lf1-f41.google.com. [209.85.167.41]) by smtp.gmail.com with ESMTPSA id f7-20020a056512092700b0047255d21108sm1292171lft.55.2022.05.04.13.40.23 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 May 2022 13:40:24 -0700 (PDT) Received: by mail-lf1-f41.google.com with SMTP id p12so4325873lfs.5 for ; Wed, 04 May 2022 13:40:23 -0700 (PDT) X-Received: by 2002:a05:6512:3a4:b0:473:b9ea:7673 with SMTP id v4-20020a05651203a400b00473b9ea7673mr3445886lfp.687.1651696823645; Wed, 04 May 2022 13:40:23 -0700 (PDT) Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: In-Reply-To: From: Linus Torvalds Date: Wed, 4 May 2022 13:40:07 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [patch 02/14] tmpfs: fix regressions from wider use of ZERO_PAGE To: Borislav Petkov Cc: Mark Hemment , Andrew Morton , "the arch/x86 maintainers" , Peter Zijlstra , patrice.chotard@foss.st.com, Mikulas Patocka , Lukas Czerner , Christoph Hellwig , "Darrick J. Wong" , Chuck Lever , Hugh Dickins , patches@lists.linux.dev, Linux-MM , mm-commits@vger.kernel.org, Mel Gorman Content-Type: text/plain; charset="UTF-8" On Wed, May 4, 2022 at 1:18 PM Borislav Petkov wrote: > > Zen3 has FSRM. Sadly, I'm on Zen2 with my 3970X, and the Zen 3 threadrippers seem to be basically impossible to get. > So below's the git test suite with clear_user on Zen3. It creates a lot > of processes so we get to clear_user a bunch and that's the inlined rep > movsb. Oh, the clear_user() in the ELF loader? I wouldn't have expected that to be noticeable. Now, clear_page() is *very* noticeable, but that has its own special magic and doesn't use clear_user(). Maybe there is some other clear_user() case I never thought of. My dim memories of profiles definitely had copy_to_user, clear_page and copy_page being some of the top copy loops. Linus