From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8FF6855C0A for ; Thu, 2 May 2024 09:04:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714640648; cv=none; b=Iuu7AsdG5FhFvMCH1pSCfVGIuf4JQjl70u7CJYrp3qcwTC0n42rjWhW7AacCNpWvrEKE6ilkbFnxhsyw0Cf7IYbUVvpb8i1bl2Npx/RJNNNDnV/ziV5El00iwpsprtzg7YFm46uLTcrSybUs0mqvZj97ukB4IAqeonQhBqc2VQg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714640648; c=relaxed/simple; bh=RBNo7t5IGu2yThFFulb8qCfz4Zt2E7C/FOw15MNEb5o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XDZWS1nBmQzkwFzQiGg6am+9kMO3L06zAYRk1Kf803yl8doHSMURmtbia0RS/r3gv1P5lmAcD7GyU9AgVHOfP+zYaJUKza59PNNE9w+zuTIsfsm+O7GFr0+646R70Tr3QmjtBmg3tIEOXw5pLT/y4OAmGMj77yOXbzykUKhV8dQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=D4mYV+WD; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="D4mYV+WD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1714640645; 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: in-reply-to:in-reply-to:references:references; bh=+3z/p7PSnITLar6zjViIxQUZhsvkqQniW+UpUaJYwp0=; b=D4mYV+WDRiJksVWc5OcQTqlPfbn3jYAkPS4BBtPzyUf5D9QbsSKAwEoACpx6qigl9o7i9d kWZYTsnBXYLyd3FgqThv57+NcUA6kmGlzi3miBQ91HwOPi81S6HzroCz2OrpRwlr1baNUO tVcEJBDCn1dMpX3qHgBmZ5DJluSmfaY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-74-shbXHky0Ojewoz46za8lZg-1; Thu, 02 May 2024 05:04:04 -0400 X-MC-Unique: shbXHky0Ojewoz46za8lZg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CC69080E95D; Thu, 2 May 2024 09:04:03 +0000 (UTC) Received: from fedora (unknown [10.39.194.153]) by smtp.corp.redhat.com (Postfix) with SMTP id 36235EC685; Thu, 2 May 2024 09:04:01 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Thu, 2 May 2024 05:04:03 -0400 (EDT) Date: Thu, 2 May 2024 05:04:00 -0400 From: Oleg Nesterov To: kernel test robot Cc: oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org, Ingo Molnar , Thomas Gleixner , Phil Auld Subject: Re: kernel/sched/isolation.c:143 housekeeping_setup() warn: always true condition '(first_cpu >= 0) => (0-u32max >= 0)' Message-ID: References: <202404300915.WNvfwBz3-lkp@intel.com> Precedence: bulk X-Mailing-List: oe-kbuild-all@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202404300915.WNvfwBz3-lkp@intel.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 Hello, I am on PTO till May 9 without my working laptop, can't even read the source code. I'll return to this when I'm back. CONFIG_SMP=n I guess. On 04/30, kernel test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > head: 98369dccd2f8e16bf4c6621053af7aa4821dcf8e > commit: 257bf89d84121280904800acd25cc2c444c717ae sched/isolation: Fix boot crash when maxcpus < first housekeeping CPU > date: 2 days ago > config: xtensa-randconfig-r081-20240429 (https://download.01.org/0day-ci/archive/20240430/202404300915.WNvfwBz3-lkp@intel.com/config) > compiler: xtensa-linux-gcc (GCC) 13.2.0 > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > | Reported-by: kernel test robot > | Closes: https://lore.kernel.org/oe-kbuild-all/202404300915.WNvfwBz3-lkp@intel.com/ > > New smatch warnings: > kernel/sched/isolation.c:143 housekeeping_setup() warn: always true condition '(first_cpu >= 0) => (0-u32max >= 0)' > > Old smatch warnings: > arch/xtensa/include/asm/thread_info.h:97 current_thread_info() warn: inconsistent indenting > > vim +143 kernel/sched/isolation.c > > 117 > 118 static int __init housekeeping_setup(char *str, unsigned long flags) > 119 { > 120 cpumask_var_t non_housekeeping_mask, housekeeping_staging; > 121 unsigned int first_cpu; > 122 int err = 0; > 123 > 124 if ((flags & HK_FLAG_TICK) && !(housekeeping.flags & HK_FLAG_TICK)) { > 125 if (!IS_ENABLED(CONFIG_NO_HZ_FULL)) { > 126 pr_warn("Housekeeping: nohz unsupported." > 127 " Build with CONFIG_NO_HZ_FULL\n"); > 128 return 0; > 129 } > 130 } > 131 > 132 alloc_bootmem_cpumask_var(&non_housekeeping_mask); > 133 if (cpulist_parse(str, non_housekeeping_mask) < 0) { > 134 pr_warn("Housekeeping: nohz_full= or isolcpus= incorrect CPU range\n"); > 135 goto free_non_housekeeping_mask; > 136 } > 137 > 138 alloc_bootmem_cpumask_var(&housekeeping_staging); > 139 cpumask_andnot(housekeeping_staging, > 140 cpu_possible_mask, non_housekeeping_mask); > 141 > 142 first_cpu = cpumask_first_and(cpu_present_mask, housekeeping_staging); > > 143 if (first_cpu >= nr_cpu_ids || first_cpu >= setup_max_cpus) { > 144 __cpumask_set_cpu(smp_processor_id(), housekeeping_staging); > 145 __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask); > 146 if (!housekeeping.flags) { > 147 pr_warn("Housekeeping: must include one present CPU, " > 148 "using boot CPU:%d\n", smp_processor_id()); > 149 } > 150 } > 151 > 152 if (cpumask_empty(non_housekeeping_mask)) > 153 goto free_housekeeping_staging; > 154 > 155 if (!housekeeping.flags) { > 156 /* First setup call ("nohz_full=" or "isolcpus=") */ > 157 enum hk_type type; > 158 > 159 for_each_set_bit(type, &flags, HK_TYPE_MAX) > 160 housekeeping_setup_type(type, housekeeping_staging); > 161 } else { > 162 /* Second setup call ("nohz_full=" after "isolcpus=" or the reverse) */ > 163 enum hk_type type; > 164 unsigned long iter_flags = flags & housekeeping.flags; > 165 > 166 for_each_set_bit(type, &iter_flags, HK_TYPE_MAX) { > 167 if (!cpumask_equal(housekeeping_staging, > 168 housekeeping.cpumasks[type])) { > 169 pr_warn("Housekeeping: nohz_full= must match isolcpus=\n"); > 170 goto free_housekeeping_staging; > 171 } > 172 } > 173 > 174 iter_flags = flags & ~housekeeping.flags; > 175 > 176 for_each_set_bit(type, &iter_flags, HK_TYPE_MAX) > 177 housekeeping_setup_type(type, housekeeping_staging); > 178 } > 179 > 180 if ((flags & HK_FLAG_TICK) && !(housekeeping.flags & HK_FLAG_TICK)) > 181 tick_nohz_full_setup(non_housekeeping_mask); > 182 > 183 housekeeping.flags |= flags; > 184 err = 1; > 185 > 186 free_housekeeping_staging: > 187 free_bootmem_cpumask_var(housekeeping_staging); > 188 free_non_housekeeping_mask: > 189 free_bootmem_cpumask_var(non_housekeeping_mask); > 190 > 191 return err; > 192 } > 193 > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki >