Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751584Ab2JOIXU (ORCPT ); Mon, 15 Oct 2012 04:23:20 -0400 Received: from e36.co.us.ibm.com ([32.97.110.154]:46238 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751039Ab2JOIXP (ORCPT ); Mon, 15 Oct 2012 04:23:15 -0400 Date: Mon, 15 Oct 2012 13:54:13 +0530 From: Srikar Dronamraju To: Andrea Arcangeli Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, pzijlstr@redhat.com, mingo@elte.hu, mel@csn.ul.ie, hughd@google.com, riel@redhat.com, hannes@cmpxchg.org, dhillf@gmail.com, drjones@redhat.com, tglx@linutronix.de, pjt@google.com, cl@linux.com, suresh.b.siddha@intel.com, efault@gmx.de, paulmck@linux.vnet.ibm.com, laijs@cn.fujitsu.com, Lee.Schermerhorn@hp.com, alex.shi@intel.com, benh@kernel.crashing.org Subject: Re: [PATCH 19/33] autonuma: memory follows CPU algorithm and task/mm_autonuma stats collection Message-ID: <20121015082413.GD17364@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <1349308275-2174-1-git-send-email-aarcange@redhat.com> <1349308275-2174-20-git-send-email-aarcange@redhat.com> <20121013180618.GC31442@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20121013180618.GC31442@linux.vnet.ibm.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12101508-7606-0000-0000-00000481F79B Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2793 Lines: 59 * Srikar Dronamraju [2012-10-13 23:36:18]: > > + > > +bool numa_hinting_fault(struct page *page, int numpages) > > +{ > > + bool migrated = false; > > + > > + /* > > + * "current->mm" could be different from the "mm" where the > > + * NUMA hinting page fault happened, if get_user_pages() > > + * triggered the fault on some other process "mm". That is ok, > > + * all we care about is to count the "page_nid" access on the > > + * current->task_autonuma, even if the page belongs to a > > + * different "mm". > > + */ > > + WARN_ON_ONCE(!current->mm); > > Given the above comment, Do we really need this warn_on? > I think I have seen this warning when using autonuma. > ------------[ cut here ]------------ WARNING: at ../mm/autonuma.c:359 numa_hinting_fault+0x60d/0x7c0() Hardware name: BladeCenter HS22V -[7871AC1]- Modules linked in: ebtable_nat ebtables autofs4 sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf bridge stp llc iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 vhost_net macvtap macvlan tun iTCO_wdt iTCO_vendor_support cdc_ether usbnet mii kvm_intel kvm microcode serio_raw lpc_ich mfd_core i2c_i801 i2c_core shpchp ioatdma i7core_edac edac_core bnx2 ixgbe dca mdio sg ext4 mbcache jbd2 sd_mod crc_t10dif mptsas mptscsih mptbase scsi_transport_sas dm_mirror dm_region_hash dm_log dm_mod Pid: 116, comm: ksmd Tainted: G D 3.6.0-autonuma27+ #3 Call Trace: [] warn_slowpath_common+0x7f/0xc0 [] warn_slowpath_null+0x1a/0x20 [] numa_hinting_fault+0x60d/0x7c0 [] ? flush_tlb_mm_range+0x250/0x250 [] ? physflat_send_IPI_mask+0xe/0x10 [] ? native_send_call_func_ipi+0xa5/0xd0 [] pmd_numa_fixup+0x195/0x350 [] handle_mm_fault+0x2c4/0x3d0 [] ? follow_page+0x2fc/0x4f0 [] break_ksm+0x74/0xa0 [] break_cow+0xa2/0xb0 [] ksm_scan_thread+0xb54/0xd50 [] ? wake_up_bit+0x40/0x40 [] ? run_store+0x340/0x340 [] kthread+0x9e/0xb0 [] kernel_thread_helper+0x4/0x10 [] ? kthread_freezable_should_stop+0x70/0x70 [] ? gs_change+0x13/0x13 ---[ end trace 8f50820d1887cf93 ]- While running specjbb on a 2 node box. Seems pretty easy to produce this. -- Thanks and Regards Srikar -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/