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* Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-09-21
|\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: hw breakpoints: Fix pid namespace bug x86: Fix instruction breakpoint encoding oprofile: Add Support for Intel CPU Family 6 / Model 22 (Intel Celeron 540) kprobes: Fix Kconfig dependency
| * x86: Fix instruction breakpoint encodingFrederic Weisbecker2010-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lengths and types of breakpoints are encoded in a half byte into CPU registers. However when we extract these values and store them, we add a high half byte part to them: 0x40 to the length and 0x80 to the type. When that gets reloaded to the CPU registers, the high part is masked. While making the instruction breakpoints available for perf, I zapped that high part on instruction breakpoint encoding and that broke the arch -> generic translation used by ptrace instruction breakpoints. Writing dr7 to set an inst breakpoint was then failing. There is no apparent reason for these high parts so we could get rid of them altogether. That's an invasive change though so let's do that later and for now fix the problem by restoring that inst breakpoint high part encoding in this sole patch. Reported-by: Kelvie Wong <kelvie@ieee.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Cc: Will Deacon <will.deacon@arm.com>
| * oprofile: Add Support for Intel CPU Family 6 / Model 22 (Intel Celeron 540)Patrick Simmons2010-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds CPU type detection for the Intel Celeron 540, which is part of the Core 2 family according to Wikipedia; the family and ID pair is absent from the Volume 3B table referenced in the source code comments. I have tested this patch on an Intel Celeron 540 machine reporting itself as Family 6 Model 22, and OProfile runs on the machine without issue. Spec: http://download.intel.com/design/mobile/SPECUPDT/317667.pdf Signed-off-by: Patrick Simmons <linuxrocks123@netscape.net> Acked-by: Andi Kleen <ak@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: stable@kernel.org Signed-off-by: Robert Richter <robert.richter@amd.com>
* | lguest: update comments to reflect LHCALL_LOAD_GDT_ENTRY.Rusty Russell2010-09-20
| | | | | | | | | | | | | | | | | | | | We used to have a hypercall which reloaded the entire GDT, then we switched to one which loaded a single entry (to match the IDT code). Some comments were not updated, so fix them. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reported by: Eviatar Khen <eviatarkhen@gmail.com>
* | Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2010-09-16
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: hpet: Work around hardware stupidity x86, build: Disable -fPIE when compiling with CONFIG_CC_STACKPROTECTOR=y x86, cpufeature: Suppress compiler warning with gcc 3.x x86, UV: Fix initialization of max_pnode
| * | x86: hpet: Work around hardware stupidityThomas Gleixner2010-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This more or less reverts commits 08be979 (x86: Force HPET readback_cmp for all ATI chipsets) and 30a564be (x86, hpet: Restrict read back to affected ATI chipsets) to the status of commit 8da854c (x86, hpet: Erratum workaround for read after write of HPET comparator). The delta to commit 8da854c is mostly comments and the change from WARN_ONCE to printk_once as we know the call path of this function already. This needs really in depth explanation: First of all the HPET design is a complete failure. Having a counter compare register which generates an interrupt on matching values forces the software to do at least one superfluous readback of the counter register. While it is nice in theory to program "absolute" time events it is practically useless because the timer runs at some absurd frequency which can never be matched to real world units. So we are forced to calculate a relative delta and this forces a readout of the actual counter value, adding the delta and programming the compare register. When the delta is small enough we run into the danger that we program a compare value which is already in the past. Due to the compare for equal nature of HPET we need to read back the counter value after writing the compare rehgister (btw. this is necessary for absolute timeouts as well) to make sure that we did not miss the timer event. We try to work around that by setting the minimum delta to a value which is larger than the theoretical time which elapses between the counter readout and the compare register write, but that's only true in theory. A NMI or SMI which hits between the readout and the write can easily push us beyond that limit. This would result in waiting for the next HPET timer interrupt until the 32bit wraparound of the counter happens which takes about 306 seconds. So we designed the next event function to look like: match = read_cnt() + delta; write_compare_ref(match); return read_cnt() < match ? 0 : -ETIME; At some point we got into trouble with certain ATI chipsets. Even the above "safe" procedure failed. The reason was that the write to the compare register was delayed probably for performance reasons. The theory was that they wanted to avoid the synchronization of the write with the HPET clock, which is understandable. So the write does not hit the compare register directly instead it goes to some intermediate register which is copied to the real compare register in sync with the HPET clock. That opens another window for hitting the dreaded "wait for a wraparound" problem. To work around that "optimization" we added a read back of the compare register which either enforced the update of the just written value or just delayed the readout of the counter enough to avoid the issue. We unfortunately never got any affirmative info from ATI/AMD about this. One thing is sure, that we nuked the performance "optimization" that way completely and I'm pretty sure that the result is worse than before some HW folks came up with those. Just for paranoia reasons I added a check whether the read back compare register value was the same as the value we wrote right before. That paranoia check triggered a couple of years after it was added on an Intel ICH9 chipset. Venki added a workaround (commit 8da854c) which was reading the compare register twice when the first check failed. We considered this to be a penalty in general and restricted the readback (thus the wasted CPU cycles) to the known to be affected ATI chipsets. This turned out to be a utterly wrong decision. 2.6.35 testers experienced massive problems and finally one of them bisected it down to commit 30a564be which spured some further investigation. Finally we got confirmation that the write to the compare register can be delayed by up to two HPET clock cycles which explains the problems nicely. All we can do about this is to go back to Venki's initial workaround in a slightly modified version. Just for the record I need to say, that all of this could have been avoided if hardware designers and of course the HPET committee would have thought about the consequences for a split second. It's out of my comprehension why designing a working timer is so hard. There are two ways to achieve it: 1) Use a counter wrap around aware compare_reg <= counter_reg implementation instead of the easy compare_reg == counter_reg Downsides: - It needs more silicon. - It needs a readout of the counter to apply a relative timeout. This is necessary as the counter does not run in any useful (and adjustable) frequency and there is no guarantee that the counter which is used for timer events is the same which is used for reading the actual time (and therefor for calculating the delta) Upsides: - None 2) Use a simple down counter for relative timer events Downsides: - Absolute timeouts are not possible, which is not a problem at all in the context of an OS and the expected max. latencies/jitter (also see Downsides of #1) Upsides: - It needs less or equal silicon. - It works ALWAYS - It is way faster than a compare register based solution (One write versus one write plus at least one and up to four reads) I would not be so grumpy about all of this, if I would not have been ignored for many years when pointing out these flaws to various hardware folks. I really hate timers (at least those which seem to be designed by janitors). Though finally we got a reasonable explanation plus a solution and I want to thank all the folks involved in chasing it down and providing valuable input to this. Bisected-by: Nix <nix@esperi.org.uk> Reported-by: Artur Skawina <art.08.09@gmail.com> Reported-by: Damien Wyart <damien.wyart@free.fr> Reported-by: John Drescher <drescherjm@gmail.com> Cc: Venkatesh Pallipadi <venki@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Borislav Petkov <borislav.petkov@amd.com> Cc: stable@kernel.org Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | x86, build: Disable -fPIE when compiling with CONFIG_CC_STACKPROTECTOR=ybasile@opensource.dyc.edu2010-09-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The arch/x86/Makefile uses scripts/gcc-x86_$(BITS)-has-stack-protector.sh to check if cc1 supports -fstack-protector. When -fPIE is passed to cc1, these scripts fail causing stack protection to be disabled even when it is available. This fix is similar to commit c47efe5548abbf53c2f66e06dcb46183b11d6b22 Reported-by: Kai Dietrich <mail@cleeus.de> Signed-off-by: Magnus Granberg <zorry@gentoo.org> LKML-Reference: <20100913101319.748A1148E216@opensource.dyc.edu> Signed-off-by: Anthony G. Basile <basile@opensource.dyc.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * | x86, cpufeature: Suppress compiler warning with gcc 3.xTetsuo Handa2010-09-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Gcc 3.x generates a warning arch/x86/include/asm/cpufeature.h: In function `__static_cpu_has': arch/x86/include/asm/cpufeature.h:326: warning: asm operand 1 probably doesn't match constraints on each file. But static_cpu_has() for gcc 3.x does not need __static_cpu_has(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> LKML-Reference: <201008300127.o7U1RC6Z044051@www262.sakura.ne.jp> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * | x86, UV: Fix initialization of max_pnodeJack Steiner2010-09-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix calculation of "max_pnode" for systems where the the highest blade has neither cpus or memory. (And, yes, although rare this does occur). Signed-off-by: Jack Steiner <steiner@sgi.com> LKML-Reference: <20100910150808.GA19802@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | x86-64, compat: Retruncate rax after ia32 syscall entry tracingRoland McGrath2010-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit d4d6715, we reopened an old hole for a 64-bit ptracer touching a 32-bit tracee in system call entry. A %rax value set via ptrace at the entry tracing stop gets used whole as a 32-bit syscall number, while we only check the low 32 bits for validity. Fix it by truncating %rax back to 32 bits after syscall_trace_enter, in addition to testing the full 64 bits as has already been added. Reported-by: Ben Hawkes <hawkes@sota.gen.nz> Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* | | x86-64, compat: Test %rax for the syscall number, not %eaxH. Peter Anvin2010-09-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On 64 bits, we always, by necessity, jump through the system call table via %rax. For 32-bit system calls, in theory the system call number is stored in %eax, and the code was testing %eax for a valid system call number. At one point we loaded the stored value back from the stack to enforce zero-extension, but that was removed in checkin d4d67150165df8bf1cc05e532f6efca96f907cab. An actual 32-bit process will not be able to introduce a non-zero-extended number, but it can happen via ptrace. Instead of re-introducing the zero-extension, test what we are actually going to use, i.e. %rax. This only adds a handful of REX prefixes to the code. Reported-by: Ben Hawkes <hawkes@sota.gen.nz> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@kernel.org> Cc: Roland McGrath <roland@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org>
* | | compat: Make compat_alloc_user_space() incorporate the access_ok()H. Peter Anvin2010-09-14
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | compat_alloc_user_space() expects the caller to independently call access_ok() to verify the returned area. A missing call could introduce problems on some architectures. This patch incorporates the access_ok() check into compat_alloc_user_space() and also adds a sanity check on the length. The existing compat_alloc_user_space() implementations are renamed arch_compat_alloc_user_space() and are used as part of the implementation of the new global function. This patch assumes NULL will cause __get_user()/__put_user() to either fail or access userspace on all architectures. This should be followed by checking the return value of compat_access_user_space() for NULL in the callers, at which time the access_ok() in the callers can also be removed. Reported-by: Ben Hawkes <hawkes@sota.gen.nz> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tony Luck <tony.luck@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: James Bottomley <jejb@parisc-linux.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: <stable@kernel.org>
* | x86, tsc: Fix a preemption leak in restore_sched_clock_state()Peter Zijlstra2010-09-10
| | | | | | | | | | | | | | | | | | A real life genuine preemption leak.. Reported-and-tested-by: Jeff Chua <jeff.chua.linux@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2010-09-10
|\ \ | |/ |/| | | | | | | | | | | * 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Perform hardware_enable in CPU_STARTING callback KVM: i8259: fix migration KVM: fix i8259 oops when no vcpus are online KVM: x86 emulator: fix regression with cmpxchg8b on i386 hosts
| * KVM: i8259: fix migrationGleb Natapov2010-09-08
| | | | | | | | | | | | | | | | Top of kvm_kpic_state structure should have the same memory layout as kvm_pic_state since it is copied by memcpy. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * KVM: fix i8259 oops when no vcpus are onlineAvi Kivity2010-09-08
| | | | | | | | | | | | | | If there are no vcpus, found will be NULL. Check before doing anything with it. Signed-off-by: Avi Kivity <avi@redhat.com>
| * KVM: x86 emulator: fix regression with cmpxchg8b on i386 hostsAvi Kivity2010-09-08
| | | | | | | | | | | | | | | | | | | | | | operand::val and operand::orig_val are 32-bit on i386, whereas cmpxchg8b operands are 64-bit. Fix by adding val64 and orig_val64 union members to struct operand, and using them where needed. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* | Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2010-09-08
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, mcheck: Avoid duplicate sysfs links/files for thresholding banks io-mapping: Fix the address space annotations x86: Fix the address space annotations of iomap_atomic_prot_pfn() x86, mm: Fix CONFIG_VMSPLIT_1G and 2G_OPT trampoline x86, hwmon: Fix unsafe smp_processor_id() in thermal_throttle_add_dev
| * | x86, mcheck: Avoid duplicate sysfs links/files for thresholding banksAndreas Herrmann2010-09-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kobject_add_internal failed for threshold_bank2 with -EEXIST, don't try to register things with the same name in the same directory: Pid: 1, comm: swapper Tainted: G W 2.6.31 #1 Call Trace: [<ffffffff81161b07>] ? kobject_add_internal+0x156/0x180 [<ffffffff81161cc0>] ? kobject_add+0x66/0x6b [<ffffffff81161793>] ? kobject_init+0x42/0x82 [<ffffffff81161cf9>] ? kobject_create_and_add+0x34/0x63 [<ffffffff81393963>] ? threshold_create_bank+0x14f/0x259 [<ffffffff8139310a>] ? mce_create_device+0x8d/0x1b8 [<ffffffff81646497>] ? threshold_init_device+0x3f/0x80 [<ffffffff81646458>] ? threshold_init_device+0x0/0x80 [<ffffffff81009050>] ? do_one_initcall+0x4f/0x143 [<ffffffff816413a0>] ? kernel_init+0x14c/0x1a2 [<ffffffff8100c8da>] ? child_rip+0xa/0x20 [<ffffffff81641254>] ? kernel_init+0x0/0x1a2 [<ffffffff8100c8d0>] ? child_rip+0x0/0x20 kobject_create_and_add: kobject_add error: -17 (Probably the for_each_cpu loop should be entirely removed.) Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> LKML-Reference: <20100827092006.GB5348@loge.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | x86: Fix the address space annotations of iomap_atomic_prot_pfn()Francisco Jerez2010-09-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes the sparse warnings when the return pointer of iomap_atomic_prot_pfn() is used as an argument of iowrite32() and friends. Signed-off-by: Francisco Jerez <currojerez@riseup.net> LKML-Reference: <1283633804-11749-1-git-send-email-currojerez@riseup.net> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | x86, mm: Fix CONFIG_VMSPLIT_1G and 2G_OPT trampolineHugh Dickins2010-08-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rc2 kernel crashes when booting second cpu on this CONFIG_VMSPLIT_2G_OPT laptop: whereas cloning from kernel to low mappings pgd range does need to limit by both KERNEL_PGD_PTRS and KERNEL_PGD_BOUNDARY, cloning kernel pgd range itself must not be limited by the smaller KERNEL_PGD_BOUNDARY. Signed-off-by: Hugh Dickins <hughd@google.com> LKML-Reference: <alpine.LSU.2.00.1008242235120.2515@sister.anvils> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | x86, hwmon: Fix unsafe smp_processor_id() in thermal_throttle_add_devSergey Senozhatsky2010-08-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix BUG: using smp_processor_id() in preemptible thermal_throttle_add_dev. We know the cpu number when calling thermal_throttle_add_dev, so we can remove smp_processor_id call in thermal_throttle_add_dev by supplying the cpu number as argument. This should resolve kernel bugzilla 16615/16629. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> LKML-Reference: <20100820073634.GB5209@swordfish.minsk.epam.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Joerg Roedel <Joerg.Roedel@amd.com> Cc: Maciej Rutecki <maciej.rutecki@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | | Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-09-08
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf, x86: Try to handle unknown nmis with an enabled PMU perf, x86: Fix handle_irq return values perf, x86: Fix accidentally ack'ing a second event on intel perf counter oprofile, x86: fix init_sysfs() function stub lockup_detector: Sync touch_*_watchdog back to old semantics tracing: Fix a race in function profile oprofile, x86: fix init_sysfs error handling perf_events: Fix time tracking for events with pid != -1 and cpu != -1 perf: Initialize callchains roots's childen hits oprofile: fix crash when accessing freed task structs
| * | perf, x86: Try to handle unknown nmis with an enabled PMURobert Richter2010-09-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the PMU is enabled it is valid to have unhandled nmis, two events could trigger 'simultaneously' raising two back-to-back NMIs. If the first NMI handles both, the latter will be empty and daze the CPU. The solution to avoid an 'unknown nmi' massage in this case was simply to stop the nmi handler chain when the PMU is enabled by stating the nmi was handled. This has the drawback that a) we can not detect unknown nmis anymore, and b) subsequent nmi handlers are not called. This patch addresses this. Now, we check this unknown NMI if it could be a PMU back-to-back NMI. Otherwise we pass it and let the kernel handle the unknown nmi. This is a debug log: cpu #6, nmi #32333, skip_nmi #32330, handled = 1, time = 1934364430 cpu #6, nmi #32334, skip_nmi #32330, handled = 1, time = 1934704616 cpu #6, nmi #32335, skip_nmi #32336, handled = 2, time = 1936032320 cpu #6, nmi #32336, skip_nmi #32336, handled = 0, time = 1936034139 cpu #6, nmi #32337, skip_nmi #32336, handled = 1, time = 1936120100 cpu #6, nmi #32338, skip_nmi #32336, handled = 1, time = 1936404607 cpu #6, nmi #32339, skip_nmi #32336, handled = 1, time = 1937983416 cpu #6, nmi #32340, skip_nmi #32341, handled = 2, time = 1938201032 cpu #6, nmi #32341, skip_nmi #32341, handled = 0, time = 1938202830 cpu #6, nmi #32342, skip_nmi #32341, handled = 1, time = 1938443743 cpu #6, nmi #32343, skip_nmi #32341, handled = 1, time = 1939956552 cpu #6, nmi #32344, skip_nmi #32341, handled = 1, time = 1940073224 cpu #6, nmi #32345, skip_nmi #32341, handled = 1, time = 1940485677 cpu #6, nmi #32346, skip_nmi #32347, handled = 2, time = 1941947772 cpu #6, nmi #32347, skip_nmi #32347, handled = 1, time = 1941949818 cpu #6, nmi #32348, skip_nmi #32347, handled = 0, time = 1941951591 Uhhuh. NMI received for unknown reason 00 on CPU 6. Do you have a strange power saving mode enabled? Dazed and confused, but trying to continue Deltas: nmi #32334 340186 nmi #32335 1327704 nmi #32336 1819 <<<< back-to-back nmi [1] nmi #32337 85961 nmi #32338 284507 nmi #32339 1578809 nmi #32340 217616 nmi #32341 1798 <<<< back-to-back nmi [2] nmi #32342 240913 nmi #32343 1512809 nmi #32344 116672 nmi #32345 412453 nmi #32346 1462095 <<<< 1st nmi (standard) handling 2 counters nmi #32347 2046 <<<< 2nd nmi (back-to-back) handling one counter nmi #32348 1773 <<<< 3rd nmi (back-to-back) handling no counter! [3] For back-to-back nmi detection there are the following rules: The PMU nmi handler was handling more than one counter and no counter was handled in the subsequent nmi (see [1] and [2] above). There is another case if there are two subsequent back-to-back nmis [3]. The 2nd is detected as back-to-back because the first handled more than one counter. If the second handles one counter and the 3rd handles nothing, we drop the 3rd nmi because it could be a back-to-back nmi. Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> [ renamed nmi variable to pmu_nmi to avoid clash with .nmi in entry.S ] Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: peterz@infradead.org Cc: gorcunov@gmail.com Cc: fweisbec@gmail.com Cc: ying.huang@intel.com Cc: ming.m.lin@intel.com Cc: eranian@google.com LKML-Reference: <1283454469-1909-3-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | perf, x86: Fix handle_irq return valuesPeter Zijlstra2010-09-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we rely on the number of handled overflows, ensure all handle_irq implementations actually return the right number. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: peterz@infradead.org Cc: robert.richter@amd.com Cc: gorcunov@gmail.com Cc: fweisbec@gmail.com Cc: ying.huang@intel.com Cc: ming.m.lin@intel.com Cc: eranian@google.com LKML-Reference: <1283454469-1909-4-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | perf, x86: Fix accidentally ack'ing a second event on intel perf counterDon Zickus2010-09-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During testing of a patch to stop having the perf subsytem swallow nmis, it was uncovered that Nehalem boxes were randomly getting unknown nmis when using the perf tool. Moving the ack'ing of the PMI closer to when we get the status allows the hardware to properly re-set the PMU bit signaling another PMI was triggered during the processing of the first PMI. This allows the new logic for dealing with the shortcomings of multiple PMIs to handle the extra NMI by 'eat'ing it later. Now one can wonder why are we getting a second PMI when we disable all the PMUs in the begining of the NMI handler to prevent such a case, for that I do not know. But I know the fix below helps deal with this quirk. Tested on multiple Nehalems where the problem was occuring. With the patch, the code now loops a second time to handle the second PMI (whereas before it was not). Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: peterz@infradead.org Cc: robert.richter@amd.com Cc: gorcunov@gmail.com Cc: fweisbec@gmail.com Cc: ying.huang@intel.com Cc: ming.m.lin@intel.com Cc: eranian@google.com LKML-Reference: <1283454469-1909-2-git-send-email-dzickus@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | Merge branch 'urgent' of ↵Ingo Molnar2010-09-01
| |\ \ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/urgent
| | * | oprofile, x86: fix init_sysfs() function stubRobert Richter2010-09-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The use of the return value of init_sysfs() with commit 10f0412 oprofile, x86: fix init_sysfs error handling discovered the following build error for !CONFIG_PM: .../linux/arch/x86/oprofile/nmi_int.c: In function ‘op_nmi_init’: .../linux/arch/x86/oprofile/nmi_int.c:784: error: expected expression before ‘do’ make[2]: *** [arch/x86/oprofile/nmi_int.o] Error 1 make[1]: *** [arch/x86/oprofile] Error 2 This patch fixes this. Reported-by: Ingo Molnar <mingo@elte.hu> Cc: stable@kernel.org Signed-off-by: Robert Richter <robert.richter@amd.com>
| | * | oprofile, x86: fix init_sysfs error handlingRobert Richter2010-08-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On failure init_sysfs() might not properly free resources. The error code of the function is not checked. And, when reinitializing the exit function might be called twice. This patch fixes all this. Cc: stable@kernel.org Signed-off-by: Robert Richter <robert.richter@amd.com>
* | | | Merge branch 'for-linus' of ↵Linus Torvalds2010-09-07
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: PCI: bus speed strings should be const PCI hotplug: Fix build with CONFIG_ACPI unset PCI: PCIe: Remove the port driver module exit routine PCI: PCIe: Move PCIe PME code to the pcie directory PCI: PCIe: Disable PCIe port services during port initialization PCI: PCIe: Ask BIOS for control of all native services at once ACPI/PCI: Negotiate _OSC control bits before requesting them ACPI/PCI: Do not preserve _OSC control bits returned by a query ACPI/PCI: Make acpi_pci_query_osc() return control bits ACPI/PCI: Reorder checks in acpi_pci_osc_control_set() PCI: PCIe: Introduce commad line switch for disabling port services PCI: PCIe AER: Introduce pci_aer_available() x86/PCI: only define pci_domain_nr if PCI and PCI_DOMAINS are set PCI: provide stub pci_domain_nr function for !CONFIG_PCI configs
| * | | | x86/PCI: only define pci_domain_nr if PCI and PCI_DOMAINS are setJesse Barnes2010-08-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Otherwise we'll duplicate definitions with the pci.h stubs. Reported-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* | | | | Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-08-25
|\ \ \ \ \ | | |/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf, x86, Pentium4: Clear the P4_CCCR_FORCE_OVF flag tracing/trace_stack: Fix stack trace on ppc64
| * | | | perf, x86, Pentium4: Clear the P4_CCCR_FORCE_OVF flagLin Ming2010-08-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If on Pentium4 CPUs the FORCE_OVF flag is set then an NMI happens on every event, which can generate a flood of NMIs. Clear it. Reported-by: Vince Weaver <vweaver1@eecs.utk.edu> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2010-08-25
|\ \ \ \ \ | |/ / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, tsc, sched: Recompute cyc2ns_offset's during resume from sleep states sched: Fix rq->clock synchronization when migrating tasks
| * | | | x86, tsc, sched: Recompute cyc2ns_offset's during resume from sleep statesSuresh Siddha2010-08-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TSC's get reset after suspend/resume (even on cpu's with invariant TSC which runs at a constant rate across ACPI P-, C- and T-states). And in some systems BIOS seem to reinit TSC to arbitrary large value (still sync'd across cpu's) during resume. This leads to a scenario of scheduler rq->clock (sched_clock_cpu()) less than rq->age_stamp (introduced in 2.6.32). This leads to a big value returned by scale_rt_power() and the resulting big group power set by the update_group_power() is causing improper load balancing between busy and idle cpu's after suspend/resume. This resulted in multi-threaded workloads (like kernel-compilation) go slower after suspend/resume cycle on core i5 laptops. Fix this by recomputing cyc2ns_offset's during resume, so that sched_clock() continues from the point where it was left off during suspend. Reported-by: Florian Pritz <flo@xssn.at> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: <stable@kernel.org> # [v2.6.32+] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1282262618.2675.24.camel@sbsiddha-MOBL3.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | Merge branch 'for-upstream/pvhvm' of ↵Linus Torvalds2010-08-23
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://xenbits.xensource.com/people/ianc/linux-2.6 * 'for-upstream/pvhvm' of git://xenbits.xensource.com/people/ianc/linux-2.6: xen: pvhvm: make it clearer that XEN_UNPLUG_* define bits in a bitfield xen: pvhvm: rename xen_emul_unplug=ignore to =unnnecessary xen: pvhvm: allow user to request no emulated device unplug
| * | | | | xen: pvhvm: rename xen_emul_unplug=ignore to =unnnecessaryIan Campbell2010-08-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is not immediately clear what this option causes to become ignored. The actual meaning is that it is not necessary to unplug the emulated devices to safely use the PV ones, even if the platform does not support the unplug protocol. (pressumably the user will only add this option if they have ensured that their domain configuration is safe). I think xen_emul_unplug=unnecessary better captures this. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
| * | | | | xen: pvhvm: allow user to request no emulated device unplugIan Campbell2010-08-23
| | |_|/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | this allows the user to disable pvhvm and revert to emulated devices in case of a system misconfiguration (e.g. initramfs with only emulated drivers in it). Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
* | | | | Merge branch 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2010-08-22
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: PIT: free irq source id in handling error path KVM: destroy workqueue on kvm_create_pit() failures KVM: fix poison overwritten caused by using wrong xstate size
| * | | | | KVM: PIT: free irq source id in handling error pathXiao Guangrong2010-08-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Free irq source id if create pit workqueue fail Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | | | KVM: destroy workqueue on kvm_create_pit() failuresXiaotian Feng2010-08-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernel needs to destroy workqueue if kvm_create_pit() fails, otherwise after pit is freed, the workqueue is leaked. Signed-off-by: Xiaotian Feng <dfeng@redhat.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Avi Kivity <avi@redhat.com>
| * | | | | KVM: fix poison overwritten caused by using wrong xstate sizeXiaotian Feng2010-08-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fpu.state is allocated from task_xstate_cachep, the size of task_xstate_cachep is xstate_size. xstate_size is set from cpuid instruction, which is often smaller than sizeof(struct xsave_struct). kvm is using sizeof(struct xsave_struct) to fill in/out fpu.state.xsave, as what we allocated for fpu.state is xstate_size, kernel will write out of memory and caused poison/redzone/padding overwritten warnings. Signed-off-by: Xiaotian Feng <dfeng@redhat.com> Reviewed-by: Sheng Yang <sheng@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Avi Kivity <avi@redhat.com> Cc: Robert Richter <robert.richter@amd.com> Cc: Sheng Yang <sheng@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | | | | | Replace Configure with Enable in description of MAXSMPSamuel Thibault2010-08-21
| |_|_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "Configure" word tends to make user believe they have to say 'yes' to be able to choose the number of procs/nodes. "Enable" should be unambiguous enough. Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2010-08-20
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, apic: Fix apic=debug boot crash x86, hotplug: Serialize CPU hotplug to avoid bringup concurrency issues x86-32: Fix dummy trampoline-related inline stubs x86-32: Separate 1:1 pagetables from swapper_pg_dir x86, cpu: Fix regression in AMD errata checking code
| * | | | | x86, apic: Fix apic=debug boot crashDaniel Kiper2010-08-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a boot crash when apic=debug is used and the APIC is not properly initialized. This issue appears during Xen Dom0 kernel boot but the fix is generic and the crash could occur on real hardware as well. Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Cc: xen-devel@lists.xensource.com Cc: konrad.wilk@oracle.com Cc: jeremy@goop.org Cc: <stable@kernel.org> # .35.x, .34.x, .33.x, .32.x LKML-Reference: <20100819224616.GB9967@router-fw-old.local.net-space.pl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | x86, hotplug: Serialize CPU hotplug to avoid bringup concurrency issuesBorislav Petkov2010-08-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When testing cpu hotplug code on 32-bit we kept hitting the "CPU%d: Stuck ??" message due to multiple cores concurrently accessing the cpu_callin_mask, among others. Since these codepaths are not protected from concurrent access due to the fact that there's no sane reason for making an already complex code unnecessarily more complex - we hit the issue only when insanely switching cores off- and online - serialize hotplugging cores on the sysfs level and be done with it. [ v2.1: fix !HOTPLUG_CPU build ] Cc: <stable@kernel.org> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> LKML-Reference: <20100819181029.GC17171@aftab> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| * | | | | x86-32: Fix dummy trampoline-related inline stubsH. Peter Anvin2010-08-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix dummy inline stubs for trampoline-related functions when no trampolines exist (until we get rid of the no-trampoline case entirely.) Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Joerg Roedel <joerg.roedel@amd.com> Cc: Borislav Petkov <borislav.petkov@amd.com> LKML-Reference: <4C6C294D.3030404@zytor.com>
| * | | | | x86-32: Separate 1:1 pagetables from swapper_pg_dirJoerg Roedel2010-08-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes machine crashes which occur when heavily exercising the CPU hotplug codepaths on a 32-bit kernel. These crashes are caused by AMD Erratum 383 and result in a fatal machine check exception. Here's the scenario: 1. On 32-bit, the swapper_pg_dir page table is used as the initial page table for booting a secondary CPU. 2. To make this work, swapper_pg_dir needs a direct mapping of physical memory in it (the low mappings). By adding those low, large page (2M) mappings (PAE kernel), we create the necessary conditions for Erratum 383 to occur. 3. Other CPUs which do not participate in the off- and onlining game may use swapper_pg_dir while the low mappings are present (when leave_mm is called). For all steps below, the CPU referred to is a CPU that is using swapper_pg_dir, and not the CPU which is being onlined. 4. The presence of the low mappings in swapper_pg_dir can result in TLB entries for addresses below __PAGE_OFFSET to be established speculatively. These TLB entries are marked global and large. 5. When the CPU with such TLB entry switches to another page table, this TLB entry remains because it is global. 6. The process then generates an access to an address covered by the above TLB entry but there is a permission mismatch - the TLB entry covers a large global page not accessible to userspace. 7. Due to this permission mismatch a new 4kb, user TLB entry gets established. Further, Erratum 383 provides for a small window of time where both TLB entries are present. This results in an uncorrectable machine check exception signalling a TLB multimatch which panics the machine. There are two ways to fix this issue: 1. Always do a global TLB flush when a new cr3 is loaded and the old page table was swapper_pg_dir. I consider this a hack hard to understand and with performance implications 2. Do not use swapper_pg_dir to boot secondary CPUs like 64-bit does. This patch implements solution 2. It introduces a trampoline_pg_dir which has the same layout as swapper_pg_dir with low_mappings. This page table is used as the initial page table of the booting CPU. Later in the bringup process, it switches to swapper_pg_dir and does a global TLB flush. This fixes the crashes in our test cases. -v2: switch to swapper_pg_dir right after entering start_secondary() so that we are able to access percpu data which might not be mapped in the trampoline page table. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> LKML-Reference: <20100816123833.GB28147@aftab> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | | | | x86, cpu: Fix regression in AMD errata checking codeHans Rosenfeld2010-08-18
| | |/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A bug in the family-model-stepping matching code caused the presence of errata to go undetected when OSVW was not used. This causes hangs on some K8 systems because the E400 workaround is not enabled. Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com> LKML-Reference: <1282141190-930137-1-git-send-email-hans.rosenfeld@amd.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | | | | Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-08-19
|\ \ \ \ \ | |_|_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: kprobes/x86: Fix the return address of multiple kretprobes perf tools: Fix build error on read only source. perf, x86: Fix Intel-nhm PMU programming errata workaround