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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B8783CF3195 for ; Wed, 2 Oct 2024 04:53:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=B2ZAQKodtjVu7cBwU2oU+uI8JVPYDT8FSzV0LYMamag=; b=Gkhhj0QKfisYlijnpCmYIMscYA CAIxk/tk2ylwCGyTtsiN8w52K0IFmURAo7EhZvxjSV9nletBgfbhte6EEAO69jx5v3bEP1smcLtEb 2gX9jMpXFHC89oVOPyUW7d6Mu/wSNF2WslROjg9rwX0pdyT6LA6Nu8dxE8IG4kJXlZsY9lgyeOhoV ebkCmbIr5CHhkkGOaFrdcAnaZL4smaGr5XK5o4VuQH7q0nG4XzCeNXxcoJWxtZYDEWMqmH9n+y8p7 KvHdgqQG51bFNKjoBa+WdM+zeKrKOcsR8X6eQYc5aI/cj2eHgSkUlVuaxLbdt2xoTuYIRtfxA71al hXZtimGA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1svrN7-00000004o0s-0vMN; Wed, 02 Oct 2024 04:53:57 +0000 Received: from nyc.source.kernel.org ([147.75.193.91]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1svrN3-00000004nzt-44Tc for linux-um@lists.infradead.org; Wed, 02 Oct 2024 04:53:55 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 078A0A436C3; Wed, 2 Oct 2024 04:53:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31909C4CEC5; Wed, 2 Oct 2024 04:53:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727844831; bh=B2ZAQKodtjVu7cBwU2oU+uI8JVPYDT8FSzV0LYMamag=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CEkKxegfpkX4Zw2CaHm5skQNLmPRJhWvRWrfwNVlh+TFSz9BPuRZdgUJT+gZ23vFJ IxhXfrAdi/5Tzs2K9tvjU3gGZB7VVKI4WK6iDn0vYP8Or/TvoXD3w3WnjkCdL7pIqo yAvyTAGmv5OmjrtPe8R7vrLNoxKPxUOfc15RGQ+nZr1J+I99IYLiEMGzK5HchaL0Rb fCgXSnWAkdoQPpNtPUVza5lz7aLWm5cSFY86HH4WWW1emta+IbTxS2QRhxf7N54ops vKi+l2ymUNL9BK54SZfzJOyLLVNlGP4C8ThAbAA+5rGKWDt7DLBpJn9rzmHQgg9i3o dEWzEr1A+63LQ== Date: Tue, 1 Oct 2024 21:53:47 -0700 From: Nathan Chancellor To: Wentao Zhang Cc: Matt.Kelly2@boeing.com, akpm@linux-foundation.org, andrew.j.oppelt@boeing.com, anton.ivanov@cambridgegreys.com, ardb@kernel.org, arnd@arndb.de, bhelgaas@google.com, bp@alien8.de, chuck.wolber@boeing.com, dave.hansen@linux.intel.com, dvyukov@google.com, hpa@zytor.com, jinghao7@illinois.edu, johannes@sipsolutions.net, jpoimboe@kernel.org, justinstitt@google.com, kees@kernel.org, kent.overstreet@linux.dev, linux-arch@vger.kernel.org, linux-efi@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-um@lists.infradead.org, llvm@lists.linux.dev, luto@kernel.org, marinov@illinois.edu, masahiroy@kernel.org, maskray@google.com, mathieu.desnoyers@efficios.com, matthew.l.weber3@boeing.com, mhiramat@kernel.org, mingo@redhat.com, morbo@google.com, ndesaulniers@google.com, oberpar@linux.ibm.com, paulmck@kernel.org, peterz@infradead.org, richard@nod.at, rostedt@goodmis.org, samitolvanen@google.com, samuel.sarkisian@boeing.com, steven.h.vanderleest@boeing.com, tglx@linutronix.de, tingxur@illinois.edu, tyxu@illinois.edu, x86@kernel.org Subject: Re: [PATCH v2 0/4] Enable measuring the kernel's Source-based Code Coverage and MC/DC with Clang Message-ID: <20241002045347.GE555609@thelio-3990X> References: <20240824230641.385839-1-wentaoz5@illinois.edu> <20240905043245.1389509-1-wentaoz5@illinois.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240905043245.1389509-1-wentaoz5@illinois.edu> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241001_215354_146149_876C3565 X-CRM114-Status: GOOD ( 17.46 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org Hi Wentao, I took this series for a spin on next-20241001 with LLVM 19.1.0 using a distribution configuration tailored for a local development VM using QEMU. You'll notice on the rebase for 6.12-rc1 but there is a small conflict in kernel/Makefile due to commit 0e8b67982b48 ("mm: move kernel/numa.c to mm/"). I initially did the build on one of my test machines which has 16 threads with 32GB of RAM and ld.lld got killed while linking vmlinux.o. Is your comment in the MC/DC patch "more memory is consumed if larger decisions are getting counted" relevant here or is that talking about runtime memory on the target device? I assume the latter but I figured I would make sure. If not, it might be worth a comment somewhere that this can also require some heftier build resources possibly? If that is not expected, I am happy to help look into why it is happening. I was able to successfully build that same configuration and setup with my primary workstation, which is much beefier. Unfortunately, the resulting kernel did not boot with my usual VM testing setup. I will see if I can narrow down a particular configuration option that causes this tomorrow because I did a test with defconfig + CONFIG_LLVM_COV_PROFILE_ALL and it booted fine. Perhaps some other option that is not compatible with this? I'll follow up with more information as I have it. On the integration front, I think the -mm tree, run by Andrew Morton, would probably be the best place to land this with Acks from the -tip folks for the x86 bits? Once the issue above has been understood, I think you can send v3 with any of the comments I made addressed and a potential fix for the above issue if necessary directly to him, instead of just on cc, so that it gets his attention. Other maintainers are free to argue that it should go through their trees instead but I think it would be good to decide on that sooner rather than later so this patchset is not stuck in limbo. Cheers, Nathan