From: Laurent Dufour <ldufour@linux.vnet.ibm.com>
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 <willy@infradead.org>,
benh@kernel.crashing.org, mpe@ellerman.id.au, paulus@samba.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
hpa@zytor.com, Will Deacon <will.deacon@arm.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
haren@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com,
npiggin@gmail.com, bsingharora@gmail.com,
Tim Chen <tim.c.chen@linux.intel.com>,
linuxppc-dev@lists.ozlabs.org, x86@kernel.org
Subject: [PATCH v5 21/22] x86/mm: Add speculative pagefault handling
Date: Wed, 11 Oct 2017 15:52:45 +0200 [thread overview]
Message-ID: <1507729966-10660-22-git-send-email-ldufour@linux.vnet.ibm.com> (raw)
In-Reply-To: <1507729966-10660-1-git-send-email-ldufour@linux.vnet.ibm.com>
From: Peter Zijlstra <peterz@infradead.org>
Try a speculative fault before acquiring mmap_sem, if it returns with
VM_FAULT_RETRY continue with the mmap_sem acquisition and do the
traditional fault.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[Clearing of FAULT_FLAG_ALLOW_RETRY is now done in
handle_speculative_fault()]
[Retry with usual fault path in the case VM_ERROR is returned by
handle_speculative_fault(). This allows signal to be delivered]
[Don't build SPF call if !CONFIG_SPF]
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
arch/x86/mm/fault.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index e2baeaa053a5..583e19d10b21 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1364,6 +1364,24 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
if (error_code & PF_INSTR)
flags |= FAULT_FLAG_INSTRUCTION;
+#ifdef CONFIG_SPF
+ if (error_code & PF_USER) {
+ fault = handle_speculative_fault(mm, address, flags);
+
+ /*
+ * We also check against VM_FAULT_ERROR because we have to
+ * raise a signal by calling later mm_fault_error() which
+ * requires the vma pointer to be set. So in that case,
+ * we fall through the normal path.
+ */
+ if (!(fault & VM_FAULT_RETRY || fault & VM_FAULT_ERROR)) {
+ perf_sw_event(PERF_COUNT_SW_SPF, 1,
+ regs, address);
+ goto done;
+ }
+ }
+#endif /* CONFIG_SPF */
+
/*
* When running in the kernel we expect faults to occur only to
* addresses in user space. All other faults represent errors in
@@ -1474,6 +1492,9 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
return;
}
+#ifdef CONFIG_SPF
+done:
+#endif
/*
* Major/minor page fault accounting. If any of the events
* returned VM_FAULT_MAJOR, we account it as a major fault.
--
2.7.4
next prev parent reply other threads:[~2017-10-11 13:54 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-11 13:52 [PATCH v5 00/22] Speculative page faults Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 01/22] x86/mm: Define CONFIG_SPF Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 02/22] powerpc/mm: " Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 03/22] mm: Dont assume page-table invariance during faults Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 04/22] mm: Prepare for FAULT_FLAG_SPECULATIVE Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 05/22] mm: Introduce pte_spinlock " Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 06/22] mm: VMA sequence count Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 07/22] mm: Protect VMA modifications using " Laurent Dufour
2017-10-26 10:18 ` Andrea Arcangeli
2017-11-02 15:16 ` Laurent Dufour
2017-11-02 17:25 ` Laurent Dufour
2017-11-02 20:08 ` Andrea Arcangeli
2017-11-06 9:47 ` Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 08/22] mm: RCU free VMAs Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 09/22] mm: Cache some VMA fields in the vm_fault structure Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 10/22] mm: Protect SPF handler against anon_vma changes Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 11/22] mm/migrate: Pass vm_fault pointer to migrate_misplaced_page() Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 12/22] mm: Introduce __lru_cache_add_active_or_unevictable Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 13/22] mm: Introduce __maybe_mkwrite() Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 14/22] mm: Introduce __vm_normal_page() Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 15/22] mm: Introduce __page_add_new_anon_rmap() Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 16/22] mm: Provide speculative fault infrastructure Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 17/22] mm: Try spin lock in speculative path Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 18/22] mm: Adding speculative page fault failure trace events Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 19/22] perf: Add a speculative page fault sw event Laurent Dufour
2017-10-11 13:52 ` [PATCH v5 20/22] perf tools: Add support for the SPF perf event Laurent Dufour
2017-10-11 13:52 ` Laurent Dufour [this message]
2017-10-11 13:52 ` [PATCH v5 22/22] powerpc/mm: Add speculative page fault Laurent Dufour
2017-10-26 8:14 ` [v5,22/22] " kemi
2017-11-02 14:11 ` Laurent Dufour
2017-11-06 10:27 ` Sergey Senozhatsky
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