search for: preemptabl

As a follow up to https://reviews.llvm.org/D20217 I would like to use lto/thinlto to refine when a symbol is marked as local/preemptable. I'm not very familiar with lto though so would appreciate some guidance about how best to go about this. Regards Sean Fertile

...this. I neglected to notice that since the new call to = flush the MMU update queue is called from the page fault handler, it can = be pre-empted. Both VMI and Xen use per-cpu variables to track lazy = mode state, as all previous calls to set, disable, or flush lazy mode = happened from a non-preemptable state. I have no idea how to convincingly produce the problem, as generating a = kernel pre-emption at the required point is, um, difficult, but it is = most certainly a real possibility, and potentially more likely than the = bug I fixed originally. Rusty, you may have to modify lguest code...

...this. I neglected to notice that since the new call to = flush the MMU update queue is called from the page fault handler, it can = be pre-empted. Both VMI and Xen use per-cpu variables to track lazy = mode state, as all previous calls to set, disable, or flush lazy mode = happened from a non-preemptable state. I have no idea how to convincingly produce the problem, as generating a = kernel pre-emption at the required point is, um, difficult, but it is = most certainly a real possibility, and potentially more likely than the = bug I fixed originally. Rusty, you may have to modify lguest code...

Hi, when creating a bigger (> 50 GB) HVM guest with maxmem > memory we get softlockups from time to time. kernel: [ 802.084335] BUG: soft lockup - CPU#1 stuck for 22s! [xend:31351] I tracked this down to the call of xc_domain_set_pod_target() and further p2m_pod_set_mem_target(). Unfortunately I can this check only with xen-4.2.2 as I don''t have a machine with enough memory for

...ibutes. The question is what optimizations are allowed for an OS specific preemption model? The function attributes add additional need for clarification. It think at the heart of this difference are assumptions about the OS preemption model. Linux by default assumes that global data/functions are preemptable, so in your example based on that model foo could not be inlined. You should also see gp save and restores around global calls for similar reasons, extra levels of indirections when loading global data etc. An alternative model is to invert the default by requiring preemptable data/functions to b...

Someone recently posted on the x2go list that he had a problem with jerky videos playing remotely on Ubuntu, but solved it by installing a low latency kernel that was available as an alternative. That made me curious as to whether CentOS has an equivalent - or a way to build something similar. -- Les Mikesell lesmikesell at gmail.com

While we're talking about this, I'd just mention again that the same issue arises for *normal* functions too, when linked into a shared library: int foo() { return 1; } int bar() { return foo(); } Now, compare: clang -fPIC -O1 -S -o - test.c gcc -fPIC -O1 -S -o - test.c GCC will refuse to inline foo into bar, or use any information about foo in compiling bar, because foo is

Ok here is a real geek question, I building my own linux kernel for my asterisk system and came across the kernel setting for the timer frequency. I have one of 3 hardcode choices 100Hz, 250 Hz and 1000Hz. From what I understand the default Freq was changed from 100Hz in kernel 2.4 to 1000Hz (1KHz) in kernel 2.6. Timing is a BIG issue in asterisk with all the TDM and zap channel stuff.

Hi, This patch series is an update of my previous paravirt_ops patches. They are loosely based on Ingo's original paravirt_ops implementation for KVM. Some of the changes since the last series include: 1) Switch to using CPUID 0x40000000 instead of using MSR writes to discover shared memory area 2) Attempt to deal with SMP guests 3) Support for generic CR read caching 4) Support for

Hi, This patch series is an update of my previous paravirt_ops patches. They are loosely based on Ingo's original paravirt_ops implementation for KVM. Some of the changes since the last series include: 1) Switch to using CPUID 0x40000000 instead of using MSR writes to discover shared memory area 2) Attempt to deal with SMP guests 3) Support for generic CR read caching 4) Support for

On Wed, 16 Apr 2008 13:46:09 +0200 Ingo Molnar <mingo at elte.hu> wrote: > > * Pekka Paalanen <pq at iki.fi> wrote: > > > > we should fix this restriction ASAP. Forcibly dropping to UP will > > > cause mmiotrace to be much less useful for diagnostic purposes of > > > Linux > > > > Ok, how do you propose we solve this? > >

...GHz 800MHz FSB (tried Celeron 2.4GHz too) IDE HDD with UDMA2 (hdparm -u1c1d1X66 /dev/hda) Asterisk, libpri and zaptel versions 1.4.0 release, Linux 2.6.20 (tried 2.6.17 and 2.6.19) I disabled all not needed devices on motherboard BIOS (even video) and compiled only needed drivers in kernel, tried preemptable and not-preemptable kernel, 100, 250 and 1000Hz timer. Looks like I haven't IRQ problem: cat /proc/interrupts CPU0 0: 182503 IO-APIC-edge timer 1: 8 IO-APIC-edge i8042 2: 0 XT-PIC-XT cascade 8: 1 IO-APIC-edge rtc...

Hi all, This is something that came up in the "RFC: Add guard intrinsics to LLVM" thread; and while I'm not exactly blocked on this, figuring out a path forward here will be helpful in deciding if we can use the available_externally linkage type to expression certain semantic properties guard intrinsics will have. Let's start with an example that shows that we have a problem

...-2017-17566 - Fix broken x86 shadow mode refcount overflow check XSA-249 CVE-2017-17563 - Fix improper x86 shadow mode refcount error handling XSA-250 CVE-2017-17564 - Fix improper bug check in x86 log-dirty handling XSA-251 CVE-2017-17565 - Fix: DoS via non-preemptable L3/L4 pagetable freeing XSA-252 CVE-2018-7540 - Fix x86: memory leak with MSR emulation XSA-253 CVE-2018-5244 - Multiple parts of fixes for... Information leak via side effects of speculative execution XSA-254 CVE-2017-5753 CVE-2017-5715 CVE-2017-5754 -...

On Sun, Nov 07 2010 at 6:05pm -0500, Andi Kleen <andi@firstfloor.org> wrote: > On Sun, Nov 07, 2010 at 10:39:23PM +0100, Milan Broz wrote: > > On 11/07/2010 08:45 PM, Andi Kleen wrote: > > >> I read about barrier-problems and data getting to the partition when > > >> using dm-crypt and several layers so I don''t know if that could be > >

A character device for accessing (in user-space) pages that have been granted by other domains. Signed-off-by: Derek Murray <Derek.Murray@cl.cam.ac.uk> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel