From patchwork Wed Oct 11 13:52:42 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Dufour X-Patchwork-Id: 824453 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3yBx5t667xz9s7M for ; Thu, 12 Oct 2017 01:22:58 +1100 (AEDT) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3yBx5t5C2TzDrWn for ; Thu, 12 Oct 2017 01:22:58 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=ldufour@linux.vnet.ibm.com; receiver=) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3yBwSL05PnzDr6n for ; Thu, 12 Oct 2017 00:53:53 +1100 (AEDT) Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v9BDogdx070673 for ; Wed, 11 Oct 2017 09:53:51 -0400 Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110]) by mx0a-001b2d01.pphosted.com with ESMTP id 2dhmgc89fu-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 11 Oct 2017 09:53:51 -0400 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 11 Oct 2017 14:53:41 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v9BDrfjk23396374; Wed, 11 Oct 2017 13:53:41 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8A6104C044; Wed, 11 Oct 2017 14:49:37 +0100 (BST) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CB4C34C040; Wed, 11 Oct 2017 14:49:35 +0100 (BST) Received: from nimbus.lab.toulouse-stg.fr.ibm.com (unknown [9.145.30.240]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 11 Oct 2017 14:49:35 +0100 (BST) From: Laurent Dufour To: paulmck@linux.vnet.ibm.com, peterz@infradead.org, akpm@linux-foundation.org, kirill@shutemov.name, ak@linux.intel.com, mhocko@kernel.org, dave@stgolabs.net, jack@suse.cz, Matthew Wilcox , benh@kernel.crashing.org, mpe@ellerman.id.au, paulus@samba.org, Thomas Gleixner , Ingo Molnar , hpa@zytor.com, Will Deacon , Sergey Senozhatsky , Andrea Arcangeli , Alexei Starovoitov Subject: [PATCH v5 18/22] mm: Adding speculative page fault failure trace events Date: Wed, 11 Oct 2017 15:52:42 +0200 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1507729966-10660-1-git-send-email-ldufour@linux.vnet.ibm.com> References: <1507729966-10660-1-git-send-email-ldufour@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17101113-0016-0000-0000-000004F4C7EE X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17101113-0017-0000-0000-0000282FD633 Message-Id: <1507729966-10660-19-git-send-email-ldufour@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-10-11_05:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710110191 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, npiggin@gmail.com, linux-mm@kvack.org, Tim Chen , haren@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" This patch a set of new trace events to collect the speculative page fault event failures. Signed-off-by: Laurent Dufour --- include/trace/events/pagefault.h | 87 ++++++++++++++++++++++++++++++++++++++++ mm/memory.c | 59 ++++++++++++++++++++++----- 2 files changed, 135 insertions(+), 11 deletions(-) create mode 100644 include/trace/events/pagefault.h diff --git a/include/trace/events/pagefault.h b/include/trace/events/pagefault.h new file mode 100644 index 000000000000..d7d56f8102d1 --- /dev/null +++ b/include/trace/events/pagefault.h @@ -0,0 +1,87 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM pagefault + +#if !defined(_TRACE_PAGEFAULT_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_PAGEFAULT_H + +#include +#include + +DECLARE_EVENT_CLASS(spf, + + TP_PROTO(unsigned long caller, + struct vm_area_struct *vma, unsigned long address), + + TP_ARGS(caller, vma, address), + + TP_STRUCT__entry( + __field(unsigned long, caller) + __field(unsigned long, vm_start) + __field(unsigned long, vm_end) + __field(unsigned long, address) + ), + + TP_fast_assign( + __entry->caller = caller; + __entry->vm_start = vma->vm_start; + __entry->vm_end = vma->vm_end; + __entry->address = address; + ), + + TP_printk("ip:%lx vma:%lu-%lx address:%lx", + __entry->caller, __entry->vm_start, __entry->vm_end, + __entry->address) +); + +DEFINE_EVENT(spf, spf_pte_lock, + + TP_PROTO(unsigned long caller, + struct vm_area_struct *vma, unsigned long address), + + TP_ARGS(caller, vma, address) +); + +DEFINE_EVENT(spf, spf_vma_changed, + + TP_PROTO(unsigned long caller, + struct vm_area_struct *vma, unsigned long address), + + TP_ARGS(caller, vma, address) +); + +DEFINE_EVENT(spf, spf_vma_dead, + + TP_PROTO(unsigned long caller, + struct vm_area_struct *vma, unsigned long address), + + TP_ARGS(caller, vma, address) +); + +DEFINE_EVENT(spf, spf_vma_noanon, + + TP_PROTO(unsigned long caller, + struct vm_area_struct *vma, unsigned long address), + + TP_ARGS(caller, vma, address) +); + +DEFINE_EVENT(spf, spf_vma_notsup, + + TP_PROTO(unsigned long caller, + struct vm_area_struct *vma, unsigned long address), + + TP_ARGS(caller, vma, address) +); + +DEFINE_EVENT(spf, spf_vma_access, + + TP_PROTO(unsigned long caller, + struct vm_area_struct *vma, unsigned long address), + + TP_ARGS(caller, vma, address) +); + +#endif /* _TRACE_PAGEFAULT_H */ + +/* This part must be outside protection */ +#include diff --git a/mm/memory.c b/mm/memory.c index d1278fc15a91..24008a86ef12 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -81,6 +81,9 @@ #include "internal.h" +#define CREATE_TRACE_POINTS +#include + #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. #endif @@ -2472,15 +2475,20 @@ static bool pte_spinlock(struct vm_fault *vmf) } local_irq_disable(); - if (vma_has_changed(vmf)) + if (vma_has_changed(vmf)) { + trace_spf_vma_changed(_RET_IP_, vmf->vma, vmf->address); goto out; + } vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd); - if (unlikely(!spin_trylock(vmf->ptl))) + if (unlikely(!spin_trylock(vmf->ptl))) { + trace_spf_pte_lock(_RET_IP_, vmf->vma, vmf->address); goto out; + } if (vma_has_changed(vmf)) { spin_unlock(vmf->ptl); + trace_spf_vma_changed(_RET_IP_, vmf->vma, vmf->address); goto out; } @@ -2519,8 +2527,10 @@ static bool pte_map_lock(struct vm_fault *vmf) * block on the PTL and thus we're safe. */ local_irq_disable(); - if (vma_has_changed(vmf)) + if (vma_has_changed(vmf)) { + trace_spf_vma_changed(_RET_IP_, vmf->vma, vmf->address); goto out; + } /* * Same as pte_offset_map_lock() except that we call @@ -2533,11 +2543,13 @@ static bool pte_map_lock(struct vm_fault *vmf) pte = pte_offset_map(vmf->pmd, vmf->address); if (unlikely(!spin_trylock(ptl))) { pte_unmap(pte); + trace_spf_pte_lock(_RET_IP_, vmf->vma, vmf->address); goto out; } if (vma_has_changed(vmf)) { pte_unmap_unlock(pte, ptl); + trace_spf_vma_changed(_RET_IP_, vmf->vma, vmf->address); goto out; } @@ -4255,32 +4267,45 @@ int handle_speculative_fault(struct mm_struct *mm, unsigned long address, * Validate the VMA found by the lockless lookup. */ dead = RB_EMPTY_NODE(&vma->vm_rb); + if (dead) { + trace_spf_vma_dead(_RET_IP_, vma, address); + goto unlock; + } + seq = raw_read_seqcount(&vma->vm_sequence); /* rmb <-> seqlock,vma_rb_erase() */ - if ((seq & 1) || dead) + if (seq & 1) { + trace_spf_vma_changed(_RET_IP_, vma, address); goto unlock; + } /* * Can't call vm_ops service has we don't know what they would do * with the VMA. * This include huge page from hugetlbfs. */ - if (vma->vm_ops) + if (vma->vm_ops) { + trace_spf_vma_notsup(_RET_IP_, vma, address); goto unlock; + } /* * __anon_vma_prepare() requires the mmap_sem to be held * because vm_next and vm_prev must be safe. This can't be guaranteed * in the speculative path. */ - if (unlikely(!vma->anon_vma)) + if (unlikely(!vma->anon_vma)) { + trace_spf_vma_notsup(_RET_IP_, vma, address); goto unlock; + } vmf.vma_flags = READ_ONCE(vma->vm_flags); vmf.vma_page_prot = READ_ONCE(vma->vm_page_prot); /* Can't call userland page fault handler in the speculative path */ - if (unlikely(vmf.vma_flags & VM_UFFD_MISSING)) + if (unlikely(vmf.vma_flags & VM_UFFD_MISSING)) { + trace_spf_vma_notsup(_RET_IP_, vma, address); goto unlock; + } #ifdef CONFIG_NUMA /* @@ -4290,25 +4315,32 @@ int handle_speculative_fault(struct mm_struct *mm, unsigned long address, pol = __get_vma_policy(vma, address); if (!pol) pol = get_task_policy(current); - if (pol && pol->mode == MPOL_INTERLEAVE) + if (pol && pol->mode == MPOL_INTERLEAVE) { + trace_spf_vma_notsup(_RET_IP_, vma, address); goto unlock; + } #endif - if (vmf.vma_flags & VM_GROWSDOWN || vmf.vma_flags & VM_GROWSUP) + if (vmf.vma_flags & VM_GROWSDOWN || vmf.vma_flags & VM_GROWSUP) { /* * This could be detected by the check address against VMA's * boundaries but we want to trace it as not supported instead * of changed. */ + trace_spf_vma_notsup(_RET_IP_, vma, address); goto unlock; + } if (address < READ_ONCE(vma->vm_start) - || READ_ONCE(vma->vm_end) <= address) + || READ_ONCE(vma->vm_end) <= address) { + trace_spf_vma_changed(_RET_IP_, vma, address); goto unlock; + } if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE, flags & FAULT_FLAG_INSTRUCTION, flags & FAULT_FLAG_REMOTE)) { + trace_spf_vma_access(_RET_IP_, vma, address); ret = VM_FAULT_SIGSEGV; goto unlock; } @@ -4316,10 +4348,12 @@ int handle_speculative_fault(struct mm_struct *mm, unsigned long address, /* This is one is required to check that the VMA has write access set */ if (flags & FAULT_FLAG_WRITE) { if (unlikely(!(vmf.vma_flags & VM_WRITE))) { + trace_spf_vma_access(_RET_IP_, vma, address); ret = VM_FAULT_SIGSEGV; goto unlock; } } else if (unlikely(!(vmf.vma_flags & (VM_READ|VM_EXEC|VM_WRITE)))) { + trace_spf_vma_access(_RET_IP_, vma, address); ret = VM_FAULT_SIGSEGV; goto unlock; } @@ -4377,8 +4411,10 @@ int handle_speculative_fault(struct mm_struct *mm, unsigned long address, * We need to re-validate the VMA after checking the bounds, otherwise * we might have a false positive on the bounds. */ - if (read_seqcount_retry(&vma->vm_sequence, seq)) + if (read_seqcount_retry(&vma->vm_sequence, seq)) { + trace_spf_vma_changed(_RET_IP_, vma, address); goto unlock; + } mem_cgroup_oom_enable(); ret = handle_pte_fault(&vmf); @@ -4401,6 +4437,7 @@ int handle_speculative_fault(struct mm_struct *mm, unsigned long address, return ret; out_walk: + trace_spf_vma_notsup(_RET_IP_, vma, address); local_irq_enable(); unlock: srcu_read_unlock(&vma_srcu, idx);