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 CBDD2C83F17 for ; Sun, 13 Jul 2025 17:28:23 +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:Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=bb1gMX6oqqkowN9Mysq4XIk/QzuqxoT8IOPSEPw+8Cs=; b=RvKqpRb7mq70IVQLrvqSCcfYn9 WsEG17KrLbHtH+5XARa32JO+fKMvpdi2fKM5f6OKzI3agimCK0mPiH+VTpAcAzDQPSrLWPM+KEns+ Auplqf0AYlpDbe/nx7gpbx5TtQdRZa+CSpzxOdWxp78oJsSYDLfEuXxW3h0A3wt6u9wLmy8qxIxMY BKzGwA9kiCDKPKSMTNvTt5m7R+aDpSZMbUOtS1ebv9q0DZ7MUu0skmh0zHyL51xsbBqVbusDKZoFV 0J4i7Ho6ky/u3421YAo+brfz/qJ05C6vSCSYyIAW4rhUBAdZrtrVpeE6e9Mwg+cT0YxN07Snwq5Y5 +Z5RStsQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ub0Ux-00000000RVJ-2PAY; Sun, 13 Jul 2025 17:28:23 +0000 Received: from out-180.mta1.migadu.com ([95.215.58.180]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1ub0Uu-00000000RKs-3Wrk for linux-um@lists.infradead.org; Sun, 13 Jul 2025 17:28:22 +0000 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1752427558; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=bb1gMX6oqqkowN9Mysq4XIk/QzuqxoT8IOPSEPw+8Cs=; b=kv6VCGbP/pfdy9Zfw83p1tgkOCjhIJE71RtWV2y6x0YaBwOcP+5Acno3UuxiqLyqQki8fs hoKFaqNUTO9eU7NT4wfDYlPDSwC/bVJJSzBeLWBnuQ2YRuVgocsFxABHN8oPwCrqZd0bEJ pEIqwBUXv6dNZu9JPhLK/OIgD3/IhIs= From: Tiwei Bie To: richard@nod.at, anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net Cc: linux-um@lists.infradead.org, tiwei.btw@antgroup.com, tiwei.bie@linux.dev Subject: [RFC PATCH 0/4] um: Add SMP support Date: Mon, 14 Jul 2025 01:25:32 +0800 Message-Id: <20250713172536.404809-1-tiwei.bie@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250713_102821_031435_A70A6B6F X-CRM114-Status: GOOD ( 10.49 ) 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 From: Tiwei Bie This is a follow-up to the discussion in this thread: https://lore.kernel.org/linux-um/20250711065021.2535362-4-tiwei.bie@linux.dev/ Currently, this is still a PoC and requires further improvements. I performed a kernel build test inside UML with 8 virtual CPUs enabled: $ tar xf linux-6.15.tar.gz $ cd linux-6.15 $ make ARCH=um defconfig > /dev/null $ time make ARCH=um -j16 > /dev/null real 6m2.529s user 43m37.665s sys 0m34.585s $ ./linux --version 6.15.0 $ cat /proc/cpuinfo | grep -c '^processor' 8 Here are some steps to try out SMP support in UML: 1. Build UML with CONFIG_SMP=y and, for example, CONFIG_NR_CPUS=8. 2. Launch a UML instance with, for example, 8 virtual CPUs. $ ./linux mem=16G ncpus=8 nohz=n seccomp=on init=/bin/sh \ ubd0=$your_rootfs_image This patchset depends on the following patchset: https://lore.kernel.org/linux-um/20250711065021.2535362-1-tiwei.bie@linux.dev/ Tiwei Bie (4): um: Stop tracking virtual CPUs via mm_cpumask() um: Remove unused cpu_data and current_cpu_data macros um: vdso: Implement __vdso_getcpu() via syscall um: Add SMP support arch/um/Kconfig | 28 ++- arch/um/include/asm/Kbuild | 3 + arch/um/include/asm/current.h | 5 +- arch/um/include/asm/hardirq.h | 24 ++- arch/um/include/asm/irqflags.h | 4 +- arch/um/include/asm/mmu.h | 7 + arch/um/include/asm/mmu_context.h | 11 -- arch/um/include/asm/pgtable.h | 2 + arch/um/include/asm/processor-generic.h | 8 +- arch/um/include/asm/smp.h | 31 +++- arch/um/include/asm/spinlock.h | 8 + arch/um/include/linux/smp-internal.h | 8 + arch/um/include/linux/time-internal.h | 3 + arch/um/include/shared/kern_util.h | 2 + arch/um/include/shared/longjmp.h | 3 +- arch/um/include/shared/os.h | 12 +- arch/um/include/shared/smp.h | 14 ++ arch/um/kernel/Makefile | 1 + arch/um/kernel/irq.c | 31 +++- arch/um/kernel/ksyms.c | 2 +- arch/um/kernel/mem.c | 2 + arch/um/kernel/process.c | 19 +- arch/um/kernel/skas/mmu.c | 16 +- arch/um/kernel/smp.c | 223 ++++++++++++++++++++++++ arch/um/kernel/time.c | 48 +++-- arch/um/kernel/tlb.c | 5 +- arch/um/kernel/trap.c | 2 +- arch/um/kernel/um_arch.c | 60 ++++++- arch/um/os-Linux/Makefile | 4 +- arch/um/os-Linux/file.c | 72 ++++++-- arch/um/os-Linux/main.c | 5 +- arch/um/os-Linux/process.c | 15 ++ arch/um/os-Linux/signal.c | 16 +- arch/um/os-Linux/skas/process.c | 1 + arch/um/os-Linux/smp.c | 44 +++++ arch/um/os-Linux/start_up.c | 3 + arch/um/os-Linux/time.c | 29 +-- arch/um/os-Linux/user_syms.c | 5 + arch/x86/um/vdso/um_vdso.c | 18 +- 39 files changed, 695 insertions(+), 99 deletions(-) create mode 100644 arch/um/include/asm/spinlock.h create mode 100644 arch/um/include/linux/smp-internal.h create mode 100644 arch/um/include/shared/smp.h create mode 100644 arch/um/kernel/smp.c create mode 100644 arch/um/os-Linux/smp.c -- 2.34.1