From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Theurer Subject: Re: kernel bug in kvm_intel Date: Sat, 31 Oct 2009 11:25:32 -0500 Message-ID: <4AEC64FC.7070908@linux.vnet.ibm.com> References: <4ACF9745.3050902@linux.vnet.ibm.com> <4AD16ACE.6040903@redhat.com> <1255372957.4883.49.camel@twinturbo.austin.ibm.com> <4AD4231F.6040608@redhat.com> <1255442640.4883.56.camel@twinturbo.austin.ibm.com> <4AD6061D.5070306@redhat.com> <1255637909.4883.129.camel@twinturbo.austin.ibm.com> <1256926052.4883.203.camel@twinturbo.austin.ibm.com> <4AEC5C24.9080506@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from e39.co.us.ibm.com ([32.97.110.160]:54099 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752831AbZJaQZq (ORCPT ); Sat, 31 Oct 2009 12:25:46 -0400 Received: from d03relay05.boulder.ibm.com (d03relay05.boulder.ibm.com [9.17.195.107]) by e39.co.us.ibm.com (8.14.3/8.13.1) with ESMTP id n9VGJoHO024135 for ; Sat, 31 Oct 2009 10:19:50 -0600 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay05.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n9VGPpon058524 for ; Sat, 31 Oct 2009 10:25:51 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id n9VGPp3J018570 for ; Sat, 31 Oct 2009 10:25:51 -0600 In-Reply-To: <4AEC5C24.9080506@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > On 10/30/2009 08:07 PM, Andrew Theurer wrote: >> >> I have finally bisected and isolated this to the following commit: >> >> ada3fa15057205b7d3f727bba5cd26b5912e350f >> http://git.kernel.org/?p=virt/kvm/kvm.git;a=commit;h=ada3fa15057205b7d3f727bba5cd26b5912e350f >> >> >>> Merge branch 'for-linus' of git://git./linux/kernel/git/tj/percpu >>> >>> * 'for-linus' of >>> git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits) >>> powerpc64: convert to dynamic percpu allocator >>> sparc64: use embedding percpu first chunk allocator >>> percpu: kill lpage first chunk allocator >>> x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA >>> percpu: update embedding first chunk allocator to handle sparse units >>> percpu: use group information to allocate vmap areas sparsely >>> vmalloc: implement pcpu_get_vm_areas() >>> vmalloc: separate out insert_vmalloc_vm() >>> percpu: add chunk->base_addr >>> percpu: add pcpu_unit_offsets[] >>> percpu: introduce pcpu_alloc_info and pcpu_group_info >>> percpu: move pcpu_lpage_build_unit_map() and >>> pcpul_lpage_dump_cfg() upward >>> percpu: add @align to pcpu_fc_alloc_fn_t >>> percpu: make @dyn_size mandatory for pcpu_setup_first_chunk() >>> percpu: drop @static_size from first chunk allocators >>> percpu: generalize first chunk allocator selection >>> percpu: build first chunk allocators selectively >>> percpu: rename 4k first chunk allocator to page >>> percpu: improve boot messages >>> percpu: fix pcpu_reclaim() locking >>> >> The previous commit (5579fd7e6aed8860ea0c8e3f11897493153b10ad) does not >> this problem. FYI, this problem only occurs when oprofile is active. >> >> Any idea what in this commit might be the issue? >> >> > > 5579 is not the preceding commit, it is the merged branch: > > commit ada3fa15057205b7d3f727bba5cd26b5912e350f > Merge: 2f82af0 5579fd7 > Author: Linus Torvalds > Date: Tue Sep 15 09:39:44 2009 -0700 > > Merge branch 'for-linus' of > git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu > > > What happens with 2f82af0? > 2f82af0 is: > Nicolas Pitre has a new email address > > Due to problems at cam.org, my nico@cam.org email address is no longer > valid. FRom now on, nico@fluxnic.net should be used instead. I have not tested that, but it doesn't seem likely that it would have anything to do with the problem. Or maybe I am misunderstanding the impact of this commit? FWIW, here is the bisect log: git bisect start # good: [227423904c709a8e60245c97081bbeb4fb500655] Merge branch 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip git bisect good 227423904c709a8e60245c97081bbeb4fb500655 # bad: [0f29f5871c165e346409f62d903f97cfad3894c5] Staging: rtl8192su: remove RTL8192SU ifdefs git bisect bad 0f29f5871c165e346409f62d903f97cfad3894c5 # bad: [ada3fa15057205b7d3f727bba5cd26b5912e350f] Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu git bisect bad ada3fa15057205b7d3f727bba5cd26b5912e350f # bad: [ada3fa15057205b7d3f727bba5cd26b5912e350f] Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu git bisect bad ada3fa15057205b7d3f727bba5cd26b5912e350f # good: [decee2e8a9538ae5476e6cb3f4b7714c92a04a2b] V4L/DVB (12485): zl10353: correct implementation of FE_READ_UNCORRECTED_BLOCKS git bisect good decee2e8a9538ae5476e6cb3f4b7714c92a04a2b # good: [0ee7e4d6d4f58c3b2d9f0ca8ad8f63abda8694b1] V4L/DVB (12694): gspca - vc032x: Change the start exchanges of the sensor hv7131r. git bisect good 0ee7e4d6d4f58c3b2d9f0ca8ad8f63abda8694b1 # good: [f58dc01ba2ca9fe3ab2ba4ca43d9c8a735cf62d8] percpu: generalize first chunk allocator selection git bisect good f58dc01ba2ca9fe3ab2ba4ca43d9c8a735cf62d8 # good: [2f82af08fcc7dc01a7e98a49a5995a77e32a2925] Nicolas Pitre has a new email address git bisect good 2f82af08fcc7dc01a7e98a49a5995a77e32a2925 # good: [cf88c79006bd6a09ad725ba0b34c0e23db20b19e] vmalloc: separate out insert_vmalloc_vm() git bisect good cf88c79006bd6a09ad725ba0b34c0e23db20b19e # good: [4518e6a0c038b98be4c480e6f4481e8676bd15dd] x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA git bisect good 4518e6a0c038b98be4c480e6f4481e8676bd15dd # good: [bcb2107fdbecef3de55d597d23453747af81ba88] sparc64: use embedding percpu first chunk allocator git bisect good bcb2107fdbecef3de55d597d23453747af81ba88 # good: [5579fd7e6aed8860ea0c8e3f11897493153b10ad] Merge branch 'for-next' into for-linus git bisect good 5579fd7e6aed8860ea0c8e3f11897493153b10ad Oh, wait, that commit was tested, in the middle of the log above. -Andrew