kernel.git/arch/x86, branch linux-3.11.y

sched, idle: Fix the idle polling state logic

2013-11-29T18:42:15Z

commit ea8117478918a4734586d35ff530721b682425be upstream. Mike reported that commit 7d1a9417 ("x86: Use generic idle loop") regressed several workloads and caused excessive reschedule interrupts. The patch in question failed to notice that the x86 code had an inverted sense of the polling state versus the new generic code (x86: default polling, generic: default !polling). Fix the two prominent x86 mwait based idle drivers and introduce a few new generic polling helpers (fixing the wrong smp_mb__after_clear_bit usage). Also switch the idle routines to using tif_need_resched() which is an immediate TIF_NEED_RESCHED test as opposed to need_resched which will end up being slightly different. Reported-by: Mike Galbraith Signed-off-by: Peter Zijlstra Cc: lenb@kernel.org Cc: tglx@linutronix.de Link: http://lkml.kernel.org/n/tip-nc03imb0etuefmzybzj7sprf@git.kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

x86: Update UV3 hub revision ID

2013-11-13T03:08:06Z

commit dd3c9c4b603c664fedc12facf180db0f1794aafe upstream. The UV3 hub revision ID is different than expected. The first revision was supposed to start at 1 but instead will start at 0. Signed-off-by: Russ Anderson Link: http://lkml.kernel.org/r/20131014161733.GA6274@sgi.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

x86: avoid remapping data in parse_setup_data()

2013-10-18T17:55:02Z

commit 30e46b574a1db7d14404e52dca8e1aa5f5155fd2 upstream. Type SETUP_PCI, added by setup_efi_pci(), may advertise a ROM size larger than early_memremap() is able to handle, which is currently limited to 256kB. If this occurs it leads to a NULL dereference in parse_setup_data(). To avoid this, remap the setup_data header and allow parsing functions for individual types to handle their own data remapping. Signed-off-by: Linn Crosetto Link: http://lkml.kernel.org/r/1376430401-67445-1-git-send-email-linn@hp.com Acked-by: Yinghai Lu Reviewed-by: Pekka Enberg Signed-off-by: H. Peter Anvin Cc: Paul Gortmaker Signed-off-by: Greg Kroah-Hartman

compiler/gcc4: Add quirk for 'asm goto' miscompilation bug

2013-10-18T17:54:57Z

commit 3f0116c3238a96bc18ad4b4acefe4e7be32fa861 upstream. Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto' constructs, as outlined here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 Implement a workaround suggested by Jakub Jelinek. Reported-and-tested-by: Fengguang Wu Reported-by: Oleg Nesterov Reported-by: Peter Zijlstra Suggested-by: Jakub Jelinek Reviewed-by: Richard Henderson Cc: Linus Torvalds Cc: Andrew Morton Link: http://lkml.kernel.org/r/20131015062351.GA4666@gmail.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

x86, efi: Don't map Boot Services on i386

2013-10-05T14:17:55Z

commit 700870119f49084da004ab588ea2b799689efaf7 upstream. Add patch to fix 32bit EFI service mapping (rhbz 726701) Multiple people are reporting hitting the following WARNING on i386, WARNING: at arch/x86/mm/ioremap.c:102 __ioremap_caller+0x3d3/0x440() Modules linked in: Pid: 0, comm: swapper Not tainted 3.9.0-rc7+ #95 Call Trace: [] warn_slowpath_common+0x5f/0x80 [] ? __ioremap_caller+0x3d3/0x440 [] ? __ioremap_caller+0x3d3/0x440 [] warn_slowpath_null+0x1d/0x20 [] __ioremap_caller+0x3d3/0x440 [] ? get_usage_chars+0xfb/0x110 [] ? vprintk_emit+0x147/0x480 [] ? efi_enter_virtual_mode+0x1e4/0x3de [] ioremap_cache+0x1a/0x20 [] ? efi_enter_virtual_mode+0x1e4/0x3de [] efi_enter_virtual_mode+0x1e4/0x3de [] start_kernel+0x286/0x2f4 [] ? repair_env_string+0x51/0x51 [] i386_start_kernel+0x12c/0x12f Due to the workaround described in commit 916f676f8 ("x86, efi: Retain boot service code until after switching to virtual mode") EFI Boot Service regions are mapped for a period during boot. Unfortunately, with the limited size of the i386 direct kernel map it's possible that some of the Boot Service regions will not be directly accessible, which causes them to be ioremap()'d, triggering the above warning as the regions are marked as E820_RAM in the e820 memmap. There are currently only two situations where we need to map EFI Boot Service regions, 1. To workaround the firmware bug described in 916f676f8 2. To access the ACPI BGRT image but since we haven't seen an i386 implementation that requires either, this simple fix should suffice for now. [ Added to changelog - Matt ] Reported-by: Bryan O'Donoghue Acked-by: Tom Zanussi Acked-by: Darren Hart Cc: Josh Triplett Cc: Matthew Garrett Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Greg Kroah-Hartman Signed-off-by: Josh Boyer Signed-off-by: Matt Fleming Signed-off-by: Greg Kroah-Hartman

x86/reboot: Add quirk to make Dell C6100 use reboot=pci automatically

2013-10-05T14:17:55Z

commit 4f0acd31c31f03ba42494c8baf6c0465150e2621 upstream. Dell PowerEdge C6100 machines fail to completely reboot about 20% of the time. Signed-off-by: Masoud Sharbiani Signed-off-by: Vinson Lee Cc: Robin Holt Cc: Russell King Cc: Guan Xuetao Link: http://lkml.kernel.org/r/1379717947-18042-1-git-send-email-vlee@freedesktop.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

sched/x86: Optimize switch_mm() for multi-threaded workloads

2013-09-27T00:21:43Z

commit 8f898fbbe5ee5e20a77c4074472a1fd088dc47d1 upstream. Dick Fowles, Don Zickus and Joe Mario have been working on improvements to perf, and noticed heavy cache line contention on the mm_cpumask, running linpack on a 60 core / 120 thread system. The cause turned out to be unnecessary atomic accesses to the mm_cpumask. When in lazy TLB mode, the CPU is only removed from the mm_cpumask if there is a TLB flush event. Most of the time, no such TLB flush happens, and the kernel skips the TLB reload. It can also skip the atomic memory set & test. Here is a summary of Joe's test results: * The __schedule function dropped from 24% of all program cycles down to 5.5%. * The cacheline contention/hotness for accesses to that bitmask went from being the 1st/2nd hottest - down to the 84th hottest (0.3% of all shared misses which is now quite cold) * The average load latency for the bit-test-n-set instruction in __schedule dropped from 10k-15k cycles down to an average of 600 cycles. * The linpack program results improved from 133 GFlops to 144 GFlops. Peak GFlops rose from 133 to 153. Reported-by: Don Zickus Reported-by: Joe Mario Tested-by: Joe Mario Signed-off-by: Rik van Riel Reviewed-by: Paul Turner Acked-by: Linus Torvalds Link: http://lkml.kernel.org/r/20130731221421.616d3d20@annuminas.surriel.com [ Made the comments consistent around the modified code. ] Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

x86/mce: Pay no attention to 'F' bit in MCACOD when parsing 'UC' errors

2013-09-27T00:21:43Z

commit 0ca06c0857aee11911f91621db14498496f2c2cd upstream. The 0x1000 bit of the MCACOD field of machine check MCi_STATUS registers is only defined for corrected errors (where it means that hardware may be filtering errors see SDM section 15.9.2.1). For uncorrected errors it may, or may not be set - so we should mask it out when checking for the architecturaly defined recoverable error signatures (see SDM 15.9.3.1 and 15.9.3.2) Acked-by: Naveen N. Rao Signed-off-by: Tony Luck Signed-off-by: Greg Kroah-Hartman

x86, amd_nb: Clarify F15h, model 30h GART and L3 support

2013-09-27T00:21:43Z

commit 7d64ac6422092adbbdaa279ab32f9d4c90a84558 upstream. F15h, models 0x30 and later don't have a GART. Note that. Also check CPUID leaf 0x80000006 for L3 prescence because there are models which don't sport an L3 cache. Signed-off-by: Aravind Gopalakrishnan [ Boris: rewrite commit message, cleanup comments. ] Signed-off-by: Borislav Petkov Signed-off-by: Greg Kroah-Hartman

Introduce [compat_]save_altstack_ex() to unbreak x86 SMAP

2013-09-27T00:21:43Z

commit bd1c149aa9915b9abb6d83d0f01dfd2ace0680b5 upstream. For performance reasons, when SMAP is in use, SMAP is left open for an entire put_user_try { ... } put_user_catch(); block, however, calling __put_user() in the middle of that block will close SMAP as the STAC..CLAC constructs intentionally do not nest. Furthermore, using __put_user() rather than put_user_ex() here is bad for performance. Thus, introduce new [compat_]save_altstack_ex() helpers that replace __[compat_]save_altstack() for x86, being currently the only architecture which supports put_user_try { ... } put_user_catch(). Reported-by: H. Peter Anvin Signed-off-by: Al Viro Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/n/tip-es5p6y64if71k8p5u08agv9n@git.kernel.org Signed-off-by: Greg Kroah-Hartman