From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f51.google.com (mail-wr1-f51.google.com [209.85.221.51]) (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 A10033D890F for ; Thu, 15 Oct 2026 18:43:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792089803; cv=none; b=nKk6IlywqfCdP/GAYP938lQz5AOxwg4xK05V/PK+vt6KRyb+S26eRCAo7/WJrKhEeAZdzQpHf1DKhOzTOrA8DfVaIGU7R1vV2trNfiOW7PWoF+/gLBXNVVB2FrQQTRK4dxICusgBgElRXVYfrlGiaRte1f6nfC5jWHefWR81FFU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792089803; c=relaxed/simple; bh=/7EgcX3zaTYfr/ZaQG+R7lx2u8NlmOHelMWPsxsol7o=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=U8Qhhd+MLqc7PhrYdYqXabNi0mJ3uY6heBuRwKpXq0aAL0I4eNrsrq57dF9q/kUfPjBXQANv0hDNb5eMhjiWUZkYaCYm6HyiHuLpeLfyKA5mojeum0yesZcj4ciTVxqbZJQxMo/OgPmj/XMtNC3FHsHVuAUJw5SZmJJtXu19CXM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=hGfidpAx; arc=none smtp.client-ip=209.85.221.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hGfidpAx" Received: by mail-wr1-f51.google.com with SMTP id ffacd0b85a97d-48bbb06e746so1144894f8f.3 for ; Thu, 15 Oct 2026 11:43:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1792089798; x=1792694598; darn=vger.kernel.org; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=FWIaifelUN6/dl97uYEKu7PfYC3t8maFY6KWuYs3hHQ=; b=hGfidpAxEtQENDZi/aeYOc6o40TZwdX4VRkynHmfh3JsxdAmPotxkW1hCqavYTGW98 05mapndtDtqqdxGlqKekfuqe0EAmWc38QRRKY+kPr67bK1UQbt+zHsEsshYW+VJfMut/ rurLsk+lYFrGgYkZGtEpsEuKC/9j23Qqmv72wlny6AZO4MeBNYNkA7rcmIwVYX8PinHc QrurFSjMqrgonDgJ8OE/XKFHpTPgO6VShp10cl2H/i7gvcZxyaEoDoz1hI8fyrvi+91i Uw+arVb2Wkw21viaOtuDJQoeZ/AuwQFqKt5+rW/PMfQAWuWa4z0zTbnlSh3MG1YRVcJP s+hA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792089798; x=1792694598; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=FWIaifelUN6/dl97uYEKu7PfYC3t8maFY6KWuYs3hHQ=; b=FpZzetyfh6lVwnJCvbKIfIq5w/vPt8Xcj7HAjL8NMSdQJa+EZzd22pZl+pCjHd+dQG 73wE+2zSEvBnHXwOJ2a2K3gNeMCTDFxGxmYzDlMJeqIkr5TV/eWAkZqxDPwAz5usSBqa jLwwyVXgwzkjPC3bqtwAFF4v2/1+2XjUCIXnNZrebS/vhknwY/biqp8MPk1yOyE5r8gZ 3n8hkkWxd9N2kPLcPuFAPzyYAwtJWv8t5LGKPXdMExX14f7nHz+BehKjI4Ej7caUgL14 FMoHoVj9Srw2ux+B9NPlsbryM6/ly5t5MnJkwNxXux0k3I7SJlWGrgkQlV6hi29BpiYX kM0A== X-Forwarded-Encrypted: i=1; AKwUvBzJGdrLYHVCWSV2iISpn2CSO/6W09cZlnlwOluQ4HN9bXfMxUHj0he+lW1W0l3syr8MCcr0BtfQvjmI@vger.kernel.org X-Gm-Message-State: AFq9FYL8zR/599L4iyTtfuOlMatrRunkOTeTGWCyEFoj42g8XbzucCwC er+9qsfZpkddO/S+ulSpz0oP7kUv84SCO4WR4g7kpZE5yLjuYDpu08BE X-Gm-Gg: AYBFou0w8o2anZFjebI+BLYzWO+0Np+uo+79u386aa9YthrlN7HTJ/6PaadeBl8aMOO zGDnF19IQo48J8X0e9iPbp5L6OWPO2t6QEZ7CldCm0lpDrfteIMEpu3VN/05SdP8yyFXgxL4DS3 qGCqQx41uSuaI7dHIPY/9xahHjaoFsC80RBRmuScl0eCsIVjRTNXQmuZ01DcOJ0MFZSZ28RROGY pOd5tQECkTiVAVm2sNz5kmBTw6FhUFSvNxlIG1To7ZFMkOmeJSplte8FBH42WXLmS38n1LOv3pY 6JKrcSV4+QgbEJhI2xSDNzBirammt4pl2xFQkOdaj9DdTt635mxdw202fobBx4bSTlOvPN82gRr 9WhCMdBxl75nJP2DR8wHM9GEIQ/bRzscJZ8JW4aJABvmh7r3vbv0adGQmZN/c2J9f6QZtI/q5/j gBkX6L1MulCkzchLq2lQkhLuz+5C3x0tW/r2lKhfIJcuv71HZHFerZ41+JL1kRFUwCpwgVi9ARE uAprJO+D01yDqTbI344btNZWla+8u0gOpE= X-Received: by 2002:a05:6000:41cd:b0:48d:f14a:917e with SMTP id ffacd0b85a97d-48df14a9316mr9600867f8f.11.1792089798346; Thu, 15 Oct 2026 11:43:18 -0700 (PDT) Received: from pumpkin (82-69-66-36.dsl.in-addr.zen.co.uk. [82.69.66.36]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48de0ab4f34sm21375242f8f.28.2026.10.15.11.43.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Oct 2026 11:43:17 -0700 (PDT) Date: Thu, 15 Oct 2026 19:43:15 +0100 From: David Laight To: Nicolas Schier Cc: Andrew Morton , mm-commits@vger.kernel.org, thunder.leizhen@huawei.com, thomas.weissschuh@linutronix.de, rostedt@goodmis.org, pmladek@suse.com, olsajiri@gmail.com, nathan@kernel.org, mcgrof@kernel.org, masahiroy@kernel.org, ljs@kernel.org, kees@kernel.org, geert@linux-m68k.org, denis.benato@linux.dev, chewi@gentoo.org, andrey.grodzovsky@crowdstrike.com, abelvesa@kernel.org, jim.cromie@gmail.com Subject: Re: + kallsyms-increase-marker-density-to-16-1-to-accelerate-lookups-fix.patch added to mm-nonmm-unstable branch Message-ID: <20261015194315.518f75d7@pumpkin> In-Reply-To: <20261015-curious-spiritual-buzzard-cd9aa8@l-nschier-aarch64> References: <20261011002340.E44771F000FF@smtp.kernel.org> <20261011154401.479c51b6@pumpkin> <20261015-curious-spiritual-buzzard-cd9aa8@l-nschier-aarch64> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 15 Oct 2026 14:11:28 +0200 Nicolas Schier wrote: > On Sun, Oct 11, 2026 at 03:44:01PM +0100, David Laight wrote: > > On Sat, 10 Oct 2026 17:23:40 -0700 > > Andrew Morton wrote: > > > > > The patch titled > > > Subject: kallsyms: copy constants from __KERNEL__ to user, drop the inclusion > > > has been added to the -mm mm-nonmm-unstable branch. Its filename is > > > kallsyms-increase-marker-density-to-16-1-to-accelerate-lookups-fix.patch > > > > There is a problem with the way this change in implemented. > > Basically the kernel Makefile (etc) only builds scripts/kallsyms if it doesn't exist. > > Why do you think so? Kbuild generates > $(objtree)/scripts/.kallsyms.o.cmd that should list all included header > files and other sources. If any of them is touched, a rebuild will > happen next time the kernel build wants kallsyms binary. It seems to > work exactly that way on my machine. Or have I overlooked something > here? > I've been doing a lot of test build through the kernel makefile. They definitely weren't doing the correct rebuilds unless I deleted both vmlinux.o and scripts/kallsyms, I didn't look why. I wasn't booting the kernel, I just wanted the .S file to link with a user program that included (most of) kernel/kallsyms.c and kernel/kallsyms_seltests.c (I've changed testing to do it differently most of the time.) I'm nearly ready to submit some patches that speed the 'by name' lookup by a factor of 12 with 256:1 markers and by 18 with 64:1. They also reduce the compressed symbol table by about 10k for my 'normal' kernel. I've also run the selftests on the .S file from an x86-64 allyesconfig kernel - don't try that with the current code regardless of the marker density. David