[JOB] the lights are burning bright at LightBits Labs

2017-02-13 Thread Muli Ben-Yehuda
LightBits Labs is a stealth-mode startup pushing the software and hardware technology boundaries in cloud-scale storage. I could tell you what this means but then we wouldn't be very stealthy. What I can tell you is that we are looking for excellent people who enjoy a challenge for a variety of

Re: HW breakpoint on physical address w/ VM

2015-08-29 Thread Muli Ben-Yehuda
On Sat, Aug 29, 2015 at 10:44:17PM +0300, Elazar Leibovich wrote: Oh, and the idea of the KVM patch is, for each physical HW bp, add a relevant entry in the spt, and set the hardware breakpoint there. This is assuming KVM HW bp works like I think they do. I'm not sure I follow what you are

Fwd: compiler/tools/architecture conference

2015-08-04 Thread Muli Ben-Yehuda
Might interest some of you. Apologies if you receive multiple copies. CALL FOR PAPERS Compiler, Architecture and Tools Conference (CATC) Intel Development Center, Haifa, Israel November 23rd, 2015 http://software.intel.com/compilerconf2015 Endorsed by the HiPEAC Network of Excellence

looking for a consultant for storage performance analysis work

2015-05-03 Thread Muli Ben-Yehuda
A former client of mine is looking for a consultant experienced in Linux for storage performance analysis work. The work should be on site in Haifa and will probably last several months. Anyone? Cheers, Muli ___ Linux-il mailing list

Re: Copying kernel stack in a generic way

2014-12-20 Thread Muli Ben-Yehuda
On Fri, Dec 19, 2014 at 02:19:07PM +, Elazar Leibovich wrote: I know where the stack ends, but how can I know where it begins? What assumptions can you make? Can you run kernel code in the VM (e.g., by cloning and restarting it)? Can you assume it's running Linux and/or Windows? Can you

Re: How do I benchmark a spin lock?

2014-11-26 Thread Muli Ben-Yehuda
On Tue, Nov 25, 2014 at 08:56:01PM +, Elazar Leibovich wrote: The first question I have in mind, is, how do you define a lock benchmark? Is your goal to minimize overhead? Is your goal to minimize the latency of a successful uncontended acquire? Is your goal to minimize bus load for

Re: Memory swap when there's apparently plenty of free RAM

2012-06-18 Thread Muli Ben-Yehuda
On Mon, Jun 18, 2012 at 03:07:34PM +0300, Eli Billauer wrote: Any idea what happened? In particular, why triggered the swap for no apparent reason? Just a guess, but it might sub-optimal VM swapiness settings. See Documentation/sysctl/vm.txt: swappiness This control is used to define how

JOB AD: developer with kernel skills

2012-04-18 Thread Muli Ben-Yehuda
Hello everyone, IBM is looking for a developer with (mad) kernel skills for the TSM FastBack team. CVs should be sent to Eran Raichstein, `eranra' at il dot ibm dot com. Location: Haifa (flexible) Description: The employee will function as part of a team that develops Data Protection

Re: Postgraduate studies

2011-08-04 Thread Muli Ben-Yehuda
On Thu, Aug 04, 2011 at 11:44:22AM +0300, guy keren wrote: so a new person should assume 5 manot. and then again - i'm not sure if this is the case in all faculties. It isn't. Generally CS is full time or not time, whereas other faculties, including EE, are more tolerant of part time graduate

practical limit on the number of UIDs

2011-06-29 Thread Muli Ben-Yehuda
Is it feasible to build a contemporary Linux system with around 1 million distinct user UIDs? Anyone tried it? We can assume only a relatively small subset of users will actually be logged in at once. Cheers, Muli ___ Linux-il mailing list

Re: practical limit on the number of UIDs

2011-06-29 Thread Muli Ben-Yehuda
On Wed, Jun 29, 2011 at 11:43:00AM +0300, Tom Goren wrote: Sounds like a job better suited for a DB backed authentication system such as LDAP. This is just off the top of my head, but for some reason I wouldn't want /etc/passwd and its relatives 1 million lines long. I shared the same

Re: looking for a way to tell gcc not to remove some code he thinks is unreachable.

2011-03-07 Thread Muli Ben-Yehuda
On Mon, Mar 07, 2011 at 12:11:36PM +0200, Erez D wrote: I have a function which is not called in a regular way, so gcc thinks it is dead code. however it is not, and i am looking for a way to tell the linker not to remove it. extern ___ Linux-il

Re: looking for a way to tell gcc not to remove some code he thinks is unreachable.

2011-03-07 Thread Muli Ben-Yehuda
On Mon, Mar 07, 2011 at 12:27:08PM +0200, Erez D wrote: int x; void a() extern void a() { x=3; } int main() { x=0; return 1; } the linker will remove function a() as it is not called from enywhere. however, i need it to be there, including

looking to buy ARM servers

2010-11-02 Thread Muli Ben-Yehuda
Hello everyone, I am looking to purchase ARM servers, preferably with the new Cortex-A15 processors. This is to run general purpose server workloads, so I would like to buy full integrated servers rather than build them up myself from embedded boards. Any ideas who sells such beasties in Israel?

Re: looking to buy ARM servers

2010-11-02 Thread Muli Ben-Yehuda
On Tue, Nov 02, 2010 at 05:11:34PM +0200, Baruch Siach wrote: On Tue, Nov 02, 2010 at 10:14:43AM +0200, Muli Ben-Yehuda wrote: I am looking to purchase ARM servers, preferably with the new Cortex-A15 processors. The Cortex-A15 core has just been announced by ARM. Don't expect to see

Re: looking to buy ARM servers

2010-11-02 Thread Muli Ben-Yehuda
On Tue, Nov 02, 2010 at 05:03:39PM +0200, Hetz Ben Hamo wrote: Hi, Why don't you take Atom processors? Because I want to run experiments on the ARM architecture. Cheers, Muli ___ Linux-il mailing list Linux-il@cs.huji.ac.il

Re: You develop in Linux and are looking for work, and are requested to provide CV as a .doc file - what would you do?

2010-08-16 Thread Muli Ben-Yehuda
On Mon, Aug 16, 2010 at 08:06:54PM +1000, Amos Shapira wrote: On 16 August 2010 17:41, Oleg Goldshmidt p...@goldshmidt.org wrote: My CV is written in LaTeX as well. I convert it to HTML using latex2html and do some relatively minor manual tweaks to the result. I go through this effort

Re: You develop in Linux and are looking for work, and are requested to provide CV as a .doc file - what would you do?

2010-08-16 Thread Muli Ben-Yehuda
On Mon, Aug 16, 2010 at 03:10:08PM +0300, Etzion Bar-Noy wrote: And I presume you edit your CV at least once a week. According to the hg log, 31 times in the last 29 months, so let's call it once a month on average. Cheers, Muli ___ Linux-il mailing

Final Call for Participation: SYSTOR 2010---The 3rd Annual Haifa Experimental Systems Conference

2010-05-10 Thread Muli Ben-Yehuda
on the conference website: https://www.research.ibm.com/haifa/conferences/systor2010/program.shtml We look forward to seeing you at SYSTOR 2010! -- Muli Ben-Yehuda | m...@il.ibm.com | +972-4-8281080 Manager, Virtualization and Systems Architecture Master Inventor, IBM Research -- Haifa

Call for Participation: SYSTOR 2010---The 3rd Annual Haifa Experimental Systems Conference

2010-04-11 Thread Muli Ben-Yehuda
, and the Sea of Galilee. The conference will take place at IBM Research - Haifa and the University of Haifa. -- Muli Ben-Yehuda | m...@il.ibm.com | +972-4-8281080 Manager, Virtualization and Systems Architecture Master Inventor, IBM Research -- Haifa

Re: better platform for virtualization

2010-01-20 Thread Muli Ben-Yehuda
On Wed, Jan 20, 2010 at 12:04:31AM +0200, Etzion Bar-Noy wrote: PV drivers were released by Oracle, who run their own virtualization platform based on XenCommunity. KVM is wasteful and requires VT support even for Linux machines. Not only that, but its virtualized hardware is legacy old

Re: better platform for virtualization

2010-01-19 Thread Muli Ben-Yehuda
has included KVM even earlier. Novell either includes or will include it soon. In fact, a Linux distro would have to work hard to *not* include it, since it's part of the upstream kernel. Xen---isn't and will never be. Cheers, Muli -- Muli Ben-Yehuda | m...@il.ibm.com | +972-4-8281080 Manager

Re: firefox and Bank Leumi web site

2009-12-15 Thread Muli Ben-Yehuda
(multiple versions). Cheers, Muli -- Muli Ben-Yehuda | m...@il.ibm.com | +972-4-8281080 Manager, Virtualization and Systems Architecture Master Inventor, IBM Research -- Haifa Second Workshop on I/O Virtualization (WIOV '10): http://sysrun.haifa.il.ibm.com/hrl/wiov2010

[JOB OFFER] systems researchers at IBM Research - Haifa

2009-11-03 Thread Muli Ben-Yehuda
CV. [1] http://www.haifa.il.ibm.com/research.html [2] The systems department: http://www.haifa.il.ibm.com/dept/stt/index.html [3] My group: http://www.haifa.il.ibm.com/dept/stt/sas.html [4] If you have what it takes, lack of a PhD is not an issue. Cheers, Muli -- Muli Ben-Yehuda | m

[OFFTOPIC?] SYSTOR 2009 Call for Participation

2009-04-07 Thread Muli Ben-Yehuda
Auslander, IBM * Ken Birman, Cornell * Danny Dolev, HUJI * Julian Satran, IBM * Marc Snir, UIUC * Willy Zwaenepoel, EPFL Program Chairs * Michael Factor, IBM * Dror Feitelson, HUJI General Chair * Miriam Allalouf, IBM Publicity Chair * Muli Ben Yehuda, IBM

looking for a kernel developer

2009-02-22 Thread Muli Ben-Yehuda
Hi, I'm looking to hire a kernel developer for my team in the IBM Haifa Research Lab for an advanced development/research position. If interested, please get in touch. Cheers, Muli ___ Linux-il mailing list Linux-il@cs.huji.ac.il

Re: Webcam Recommendations?

2008-11-24 Thread Muli Ben-Yehuda
On Mon, Nov 24, 2008 at 07:52:34PM +0200, Chaim Keren-Tzion wrote: Any recommendations for a good webcam to use with linux? (Mainly for use with Skype) I recently bought the Logitech QuickCam Notebook Deluxe, which works fine on Ubuntu 7.10 with Skype. There is one known problem (split video

Re: Monitor activation of a process (by process name) - is it possible ?

2008-06-18 Thread Muli Ben-Yehuda
On Wed, Jun 18, 2008 at 02:14:49PM +0300, Dan Shimshoni wrote: Is there a way to write an application/a kernel module which will notice when a process named xyz starts ? Yes, except that process named xxx is not very well defined. Briefly, you would need to do is hook into exec() (via a kernel

Re: [OT] Fragmentation in the community

2008-06-01 Thread Muli Ben-Yehuda
On Sun, Jun 01, 2008 at 11:22:19PM +0300, Nadav Har'El wrote: No, a planet aggregates many columns (blogs) into one newspaper. There are still a multitude of information sources - other newspapers - that it doesn't aggregate. It doesn't aggregate mailing lists like this one Use a mail to rss

Re: real hardware access for a virtual/Paravirtual machine?

2008-05-05 Thread Muli Ben-Yehuda
On Mon, May 05, 2008 at 08:58:04AM +0300, Shachar Shemesh wrote: Muli Ben-Yehuda wrote: KVM, Xen and VMWare ESX are just different implementations of the same technology, Sure, just like Windows and Linux are just different implementations of the same technology. I'll clarify

Re: mknod

2008-05-05 Thread Muli Ben-Yehuda
On Mon, May 05, 2008 at 09:59:22PM +0800, Ohad Levy wrote: Hello All, Is there any risk to give a user sudo rights of mknod? as far as I understand it now, it can only create new devices, therefor the risk for a running system is minimal. Not sure what you mean by 'new devices', if you

Re: real hardware access for a virtual/Paravirtual machine?

2008-05-04 Thread Muli Ben-Yehuda
On Sun, May 04, 2008 at 11:11:46PM +0300, Shachar Shemesh wrote: Dan Armak wrote: It does work without an IOMMU, it just doesn't protect you from a buggy driver causing DMA access to the wrong address. For other kinds of driver bugs, this might still be better than no virtualization.

Re: real hardware access for a virtual/Paravirtual machine?

2008-05-04 Thread Muli Ben-Yehuda
On Sun, May 04, 2008 at 09:26:49PM +0300, Dan Armak wrote: Xen however is a bit of a chore. should/could I use KVM instead? will it support the hardware access I need? AFAIR, yes. KVM doesn't AFAIK support direct hardware access by guest VMs. This is related to the fact that KVM and

Re: real hardware access for a virtual/Paravirtual machine?

2008-05-04 Thread Muli Ben-Yehuda
On Sun, May 04, 2008 at 11:50:20PM +0300, Hetz Ben Hamo wrote: Ok, Would someone show me any VM solution that can lock a PCI/AGP/PCIe device (such as graphics card), so it can be used with any VM exclusivly? Unfortunately passing through a graphics adapter requires some extra support to

Re: real hardware access for a virtual/Paravirtual machine?

2008-05-04 Thread Muli Ben-Yehuda
On Sun, May 04, 2008 at 06:39:51PM +0300, Shachar Shemesh wrote: Ira Abramov wrote: Howdie folks, My client needs to develop tools that communicate directly with QLA2xxx cards. at the moment, working on regular kernels he gets the machine stuck at times. I read somewhere that with Xen,

JOB: senior Linux kernel engineer

2008-05-01 Thread Muli Ben-Yehuda
IBM is looking for a senior Linux kernel engineer to join the recently acquired FilesX team. To apply, please send your CV to Keren Benes-Yosef kerenb (at) il.ibm.com. Feel free to shoot me an email if you have any questions. Quoth: Location: Haifa Description: The employee will function as

Re: What is a proper way to make User mode device (pseudo device) ?

2008-04-16 Thread Muli Ben-Yehuda
On Wed, Apr 16, 2008 at 10:58:34AM +0300, Lev Olshvang wrote: User mode application (VLC) communicates with a kernel device (in /dev) in a regular way: open+ioctl(). I have user mode SDK which I would like to use in order to implement ioctl calls. ( This SDK issues ioctl to the real

Re: Replacing kernel 2.4 - 2.6

2008-04-05 Thread Muli Ben-Yehuda
On Fri, Apr 04, 2008 at 08:14:10AM +0300, Shachar Shemesh wrote: Replace the entire hardware with a new one (optional), install a fairly recent version of Linux, and Xen 2 on it. Copy your entire current RedHat 7.2 distro to the Xen image, and replace the kernel with a 2.4 kernel of your

Re: Replacing kernel 2.4 - 2.6

2008-04-03 Thread Muli Ben-Yehuda
On Thu, Apr 03, 2008 at 12:19:32PM +0300, Shachar Shemesh wrote: My point is that the kernel (or glibc, or any other major piece of system software) usually has subtle dependencies on other pieces of system software. My point is that user space backwards compatibility is meaningless if

Re: Replacing kernel 2.4 - 2.6

2008-04-02 Thread Muli Ben-Yehuda
On Wed, Apr 02, 2008 at 09:53:25PM +0300, Aviram Jenik wrote: I have a machine that I want to replace the kernel on. It's an old Redhat 7.3 and it works; but it's too old to use an rpm. Upgrading to a newer version (or different distribution) is not an option. I intend to compile a new

Re: Replacing kernel 2.4 - 2.6

2008-04-02 Thread Muli Ben-Yehuda
On Wed, Apr 02, 2008 at 11:27:33PM +0300, Shachar Shemesh wrote: What I would suggest is to compile (on another machine) a non-modular kernel with everything you need, and install that. No initrd, no modules, nothing. I do believe it is the only sane way that this endeavor has any chance of

Re: Replacing kernel 2.4 - 2.6

2008-04-02 Thread Muli Ben-Yehuda
On Wed, Apr 02, 2008 at 11:53:36PM +0300, Shachar Shemesh wrote: As a side note, I don't know why the user space interface does not include those programs (well, I can understand about ext2 tools, assuming ext changed format since 2.4, which I don't know whether it has). We don't break

Re: [Haifux] [Haifux Lecture] User space syscall tracing andmanipulation - fakeroot-ng by Shachar Shemesh

2008-01-17 Thread Muli Ben-Yehuda
On Thu, Jan 17, 2008 at 12:45:10PM +0200, Shachar Shemesh wrote: Fakeroot-ng is a (as far as I know) first attempt to do the things usually done with LD_PRELOAD using the ptrace mechanism. It was both the trigger and the root cause of this lecture. Not sure what you mean by things usually

Re: [Haifux] [Haifux Lecture] User space syscall tracing andmanipulation - fakeroot-ng by Shachar Shemesh

2008-01-17 Thread Muli Ben-Yehuda
On Thu, Jan 17, 2008 at 02:12:31PM +0200, Shachar Shemesh wrote: 1. Automatic manipulation. Unlike strace, fakeroot-ng actually changes the program while running. Unlike gdb, it does so automatically. When I did this in the past, it was always intimately tied to what the victim was

Re: Asterisk won't detect the line was hung up

2007-12-27 Thread Muli Ben-Yehuda
On Thu, Dec 27, 2007 at 05:43:33AM -0500, Tzafrir Cohen wrote: $ grep asrecieved /usr/lib/asterisk/modules/chan_zap.so $ strings /usr/lib/asterisk/modules/chan_zap.so | grep asre asreceived It's I before E Except After C http://alt-usage-english.org/excerpts/fxibefor.html HTH, Muli

Re: Linux memory monitoring compared to MS-Windows

2007-12-18 Thread Muli Ben-Yehuda
On Tue, Dec 18, 2007 at 05:54:56PM +0200, Oded Arbel wrote: The real question - as emphasized by all the comments I received - is: can I know how much memory the process is accessing (within some time period) specifically when its more then the total of pages actually held in physical memory.

Re: Invoking my own DLL from Emacs

2007-11-22 Thread Muli Ben-Yehuda
On Thu, Nov 22, 2007 at 01:36:40PM +0200, Omer Zak wrote: I googled and searched, but found no way to do it, short of recompiling the entire Emacs. Is there any way to do this, short of expensive RPC or pipe mechanisms? The standard way of interfacing emacs to an external program is by

Re: Terminal logger

2007-11-21 Thread Muli Ben-Yehuda
On Wed, Nov 21, 2007 at 03:46:40PM +0200, Shachar Shemesh wrote: Hi all, I'm looking for a program (I knew it once) that saves to a log file every command written on a terminal, as well as its results. I need it so that when I'm instructing a class, I can then give them a log of everything

Re: RDMA question

2007-11-18 Thread Muli Ben-Yehuda
Hi Dan, On Sun, Nov 18, 2007 at 03:57:46PM +0200, Dan Shimshoni wrote: - My question is: does anybody have any experience with these kind of nics ? Can he share his experience with us ? We do, in a research environment. What would you like to know? Did usage of such nics indeed improve

Re: getting the current stack size of a given thread on linux

2007-10-07 Thread Muli Ben-Yehuda
On Sun, Oct 07, 2007 at 09:46:37AM +0200, Mike Kemelmakher wrote: Hi I'm looking for an answer for this simple question - how can I get the current stack size of a given thread ? Using getrusage() does not seem to do it. Parsing /proc/PID/smaps is an option but i would prefer to get it

Re: getting the current stack size of a given thread on linux

2007-10-07 Thread Muli Ben-Yehuda
On Sun, Oct 07, 2007 at 10:46:46AM +0200, Nadav Har'El wrote: On Sun, Oct 07, 2007, Muli Ben-Yehuda wrote about Re: getting the current stack size of a given thread on linux: pthread_attr_getstacksize(). See also pthread.h for various other thread stack manipulation routines. Muli, how

Re: getting the current stack size of a given thread on linux

2007-10-07 Thread Muli Ben-Yehuda
On Sun, Oct 07, 2007 at 11:57:57AM +0200, Mike Kemelmakher wrote: The pthread_attr_getstacksize() and pthread_attr_setstacksize() functions, respectively, shall get and set the thread _*creation*_ stacksize attribute in the attr object. What i need is current stack size of a

OT: SYSTOR 2007 Call For Participation

2007-10-07 Thread Muli Ben-Yehuda
'07 Organizing Committee: * Miriam Allalouf, IBM Haifa Research Lab * Gitit Bar-El, IBM Haifa Development Lab * Muli Ben-Yehuda, IBM Haifa Research Lab * Yitzhak (Tsahi) Birk, Technion * Eliezer Dekel, IBM Haifa Research Lab * Erez Hadad, IBM Haifa Research Lab * Arik

Re: Career advice needed

2007-09-04 Thread Muli Ben-Yehuda
On Tue, Sep 04, 2007 at 09:59:02AM +0300, Jonathan Ben Avraham wrote: but in fact do not. You don't have that marketing problem with Linux kernel programming. I wouldn't be so sure, although there's probably a difference of scale. You'd be surprised how many people call themselves kernel

Re: Career advice needed

2007-08-31 Thread Muli Ben-Yehuda
On Fri, Aug 31, 2007 at 08:35:25PM +0300, guy keren wrote: by the wa - this is true for gush dan. in the north - there are close to zero open jobs for linux kernel programmers (i would say zero - but maybe someone had such job openings lately) I know of at least two companies in the north

Re: Xen to KVM issue

2007-08-28 Thread Muli Ben-Yehuda
On Tue, Aug 28, 2007 at 04:38:48PM +0300, Oded Arbel wrote: As KVM (using qemu for IO) supports the Xen image format, KVM and Xen can both run fully-virtualized OS's (a disk image), but KVM does not have support for running para-virtualized Xen images (i.e., images that have kernels that have

Re: Linux sockets binding issues

2007-08-26 Thread Muli Ben-Yehuda
On Sun, Aug 26, 2007 at 11:16:22AM +0300, Shachar Shemesh wrote: The SO_REUSEADDR seems to solve the problem. That's fairly clean, and I have to wonder why it's not the default. Under some theoretical conditions you may get unexpected data on your connection when using SO_REUSEADDE.

Re: Linux sockets binding issues

2007-08-26 Thread Muli Ben-Yehuda
On Sun, Aug 26, 2007 at 12:22:49PM +0300, Shachar Shemesh wrote: are contradicting. No sane TCP stack will open a new socket that has the same parameters as an already existing socket. Add 4, and you have a situation that can NEVER happen. You have an interesting definition of NEVER. Surely

Re: Linux sockets binding issues

2007-08-25 Thread Muli Ben-Yehuda
On Sat, Aug 25, 2007 at 06:24:32PM +0300, ik wrote: So I'm looking for pointers and tips on what should I be looking for in order to understand what is happening. http://www.unixguide.net/network/socketfaq/4.5.shtml Cheers, Muli

Re: Memory undectable on Intel server board S5000VCL

2007-08-09 Thread Muli Ben-Yehuda
On Thu, Aug 09, 2007 at 11:23:09AM +0300, Ira Abramov wrote: the problem I am having is the PCI memory mapping. It's set at 2.5GB by default in the BIOS, and Debian Etch comes up and indeed sees only 2.5GB. I have set it up to 3.5G to lose less RAM, but I would still like to use the rest of

Re: Memory undectable on Intel server board S5000VCL

2007-08-09 Thread Muli Ben-Yehuda
On Thu, Aug 09, 2007 at 02:59:02PM +0300, Ira Abramov wrote: Quoting Muli Ben-Yehuda, from the post of Thu, 09 Aug: Because some PCI devices cannot deal with addresses over 4G. To be able to map the RAM that has physical address over 4G in the CPU's page tables, you need a PAE kernel

Re: dynamically adding a system call?

2007-07-31 Thread Muli Ben-Yehuda
On Tue, Jul 31, 2007 at 01:32:29PM +1000, Amos Shapira wrote: Hello, Is it possible to dynamically add a system call (e.g. by a kernel module)? No. As far as I'm familiar with the kernel internals I'd say that the answer is no but just in case I missed something I would like to hear from

Re: dynamically adding a system call?

2007-07-31 Thread Muli Ben-Yehuda
On Tue, Jul 31, 2007 at 10:10:05AM +0300, Gilad Ben-Yossef wrote: Anyway, you're doing the right thing. Just supply a userspace library that wraps the /dev, /proc or your new file virtual system operation for the user amnd implement you system call as a library function in it. Later,

Re: dynamically adding a system call?

2007-07-31 Thread Muli Ben-Yehuda
On Tue, Jul 31, 2007 at 10:30:52AM +0300, Shachar Shemesh wrote: Currently my plan is to add a special file under /proc or /dev which any program will be able to open and then pass the arguments through ioctl(2). why not do it the way it's meant to be done, using a custom device? That's

Re: [Haifux] [HAIFUX Lecture] The Price of Safety: Evaluating IOMMU Performance by Muli Ben-Yehuda

2007-06-11 Thread Muli Ben-Yehuda
On Fri, Jun 08, 2007 at 09:48:23AM +0300, Orr Dunkelman wrote: Next Monday, 11th of June, at 18:30 the Haifa Linux Club, will gather to hear Muli Ben-Yehuda speak about The Price of Safety: Evaluating IOMMU Performance Slides are now available at http://www.mulix.org

Re: Is pthread_mutex_lock fair?

2007-06-10 Thread Muli Ben-Yehuda
On Sun, Jun 10, 2007 at 09:09:45AM +0300, Shachar Shemesh wrote: do you have a case where this breaks your code? Not my current code, no, but waving away standard requirements merely because you don't see it as important seems inappropriate. Which standard requires this? POSIX

Re: Is pthread_mutex_lock fair?

2007-06-10 Thread Muli Ben-Yehuda
On Sun, Jun 10, 2007 at 10:06:40AM +0300, Gilad Ben-Yossef wrote: AFAIK sched_yeild() precious meaning is and has always been: put me at the end of the run queue for my priority. If there is no one else with my priority, I'll run again. Quote akpm: Changed sched_yield() semantics.

Re: [HAIFUX Lecture] The Price of Safety: Evaluating IOMMU Performance by Muli Ben-Yehuda

2007-06-09 Thread Muli Ben-Yehuda
On Sat, Jun 09, 2007 at 02:57:29PM +0300, Chava Leviatan wrote: Any chance that this interesting lecture will get to Tel-Aviv as well ? I don't have any plans at the moment to give it in Tel-Aviv. Cheers, Muli = To unsubscribe,

Re: Is pthread_mutex_lock fair?

2007-06-09 Thread Muli Ben-Yehuda
On Sat, Jun 09, 2007 at 07:12:35PM +0300, Shachar Shemesh wrote: Hi all, In principle, a mutex needs to satisfy two conditions: 1. It should never ever ever allow two threads/processes in simultaneously (exclusion) 2. A blocked process/thread should know that, sooner or later, and assuming

Re: Is pthread_mutex_lock fair?

2007-06-09 Thread Muli Ben-Yehuda
On Sat, Jun 09, 2007 at 09:15:18PM +0300, Muli Ben-Yehuda wrote: On Sat, Jun 09, 2007 at 07:12:35PM +0300, Shachar Shemesh wrote: Hi all, In principle, a mutex needs to satisfy two conditions: 1. It should never ever ever allow two threads/processes in simultaneously (exclusion) 2

Re: Is pthread_mutex_lock fair?

2007-06-09 Thread Muli Ben-Yehuda
On Sat, Jun 09, 2007 at 09:31:41PM +0300, Shachar Shemesh wrote: Muli Ben-Yehuda wrote: What happens if you you set thread scheduling to SCHED_FIFO (using pthread_attr_setschedpolicy(SCHED_FIFO), assuming _POSIX_THREAD_PRIORITY_SCHEDULING is defined on your system)? When I manage

Re: Is pthread_mutex_lock fair?

2007-06-09 Thread Muli Ben-Yehuda
On Sat, Jun 09, 2007 at 09:36:22PM +0300, Muli Ben-Yehuda wrote: On Sat, Jun 09, 2007 at 09:31:41PM +0300, Shachar Shemesh wrote: Muli Ben-Yehuda wrote: What happens if you you set thread scheduling to SCHED_FIFO (using pthread_attr_setschedpolicy(SCHED_FIFO), assuming

Re: Is pthread_mutex_lock fair?

2007-06-09 Thread Muli Ben-Yehuda
On Sat, Jun 09, 2007 at 10:41:53PM +0300, Gilad Ben-Yossef wrote: The Futex mechanism in the kernel, which pthread_mutex_lock is using (assusming you use an NPTL based system, but I think you are) is known to have fairness issues with code that does tight loops that do lock/unlock sequences,

Re: GPL Issue

2007-05-20 Thread Muli Ben-Yehuda
On Sun, May 20, 2007 at 04:38:00PM +0300, Geoffrey S. Mendelson wrote: Then someone comes along and offers big bucks, so the same code is now released as version 2, with a dual commercial/GPL license. In one case the people who did contribute code were not offered any compensation for their

Re: Fwd: 4GB Memory question

2007-05-14 Thread Muli Ben-Yehuda
On Mon, May 14, 2007 at 09:51:15AM +0300, Noam Meltzer wrote: This is from the release notes of RHEL5 (Kernel Notes). I tend to believe that it applies on hugemem as well. o X86 SMP alternatives o optimizes a single kernel image at runtime according to

Re: Fwd: 4GB Memory question

2007-05-14 Thread Muli Ben-Yehuda
On Mon, May 14, 2007 at 01:47:35PM +0300, Shachar Shemesh wrote: PAE is but an extension to the virtual memory technique, but using unaddressable memory instead of the disk. The machine has 64GB of physical memory, but can only actually address 4GB at a time. Pages of physical memory are

Re: Fwd: 4GB Memory question

2007-05-14 Thread Muli Ben-Yehuda
On Mon, May 14, 2007 at 02:42:11PM +0300, Shachar Shemesh wrote: Muli Ben-Yehuda wrote: Hmm? that doesn't sound correct. All PAE does it make it possible to have 36-bits PFNs in the PTEs, so that your physical addressability is up to 64GB. You *can* address all 64GB of physical memory

Re: Fwd: 4GB Memory question

2007-05-14 Thread Muli Ben-Yehuda
On Mon, May 14, 2007 at 03:20:10PM +0300, Shachar Shemesh wrote: Muli Ben-Yehuda wrote: You are confusing *virtual* memory and *physical* memory. PAE has nothing to do with virtual memory and everything to do with physical memory. I don't think I am. The simple truth of the matter

Re: VNC and webcam question

2007-04-10 Thread Muli Ben-Yehuda
On Tue, Apr 10, 2007 at 05:52:17PM +0300, Hetz Ben Hamo wrote: Hi people, I was wondering if anyone knows about any program which can grab images continuously from webcam and stream them using the VNC Protocol. I know that there are smart cams out there that stream using HTTP/RTSP etc, but

Re: Blooming Filters (was: Re: [Job] MySQL consultation)

2007-03-22 Thread Muli Ben-Yehuda
On Thu, Mar 22, 2007 at 10:55:11AM +0200, Peter wrote: I am not an expert on this, but any algorithm that runs in O(1) or close to that for the data size you use is a candidate. The data size should be obviously less than 2^32 for x86 at least in any indexable dimension if you want a

Re: Blooming Filters (was: Re: [Job] MySQL consultation)

2007-03-22 Thread Muli Ben-Yehuda
On Thu, Mar 22, 2007 at 11:46:36AM +0200, Tzahi Fadida wrote: With PAE you can stick in a lot more RAM on x86-32, but then your bottleneck becomes the 3GB of virtual address space for a single process. Perhaps some kind of a hardware solution can be used. I.e. attaching a pci with

Re: Using the code of dead project - Political question

2007-03-17 Thread Muli Ben-Yehuda
On Sun, Mar 18, 2007 at 02:40:25AM +0200, Maxim Veksler wrote: How should I approach this? Should I contact the developer and ask his permission to do so? Should I simply inform him that I will be forking his code? If in doubt, I always err on the side of politeness. Email the maintainer,

Re: Big Off-Topic: Finding a linux related job.

2007-03-09 Thread Muli Ben-Yehuda
On Fri, Mar 09, 2007 at 10:58:21AM +0200, Shamir Udi wrote: try IBM labs, they got big offices in Haifa. .. and we're hiring - http://www.haifa.il.ibm.com/careers.html I'm looking for a very good student to work with me on IO virtualization in Linux, Xen, KVM, your favorite open source

Re: Big Off-Topic: Finding a linux related job.

2007-03-09 Thread Muli Ben-Yehuda
On Fri, Mar 09, 2007 at 12:09:12PM +0200, Tzahi Fadida wrote: On Friday 09 March 2007 10:58, Shamir Udi wrote: try IBM labs, they got big offices in Haifa. Since you brought it up, that was the position that did not say no, but rather that the position was filled a day before my second

Re: Visual diff tool for patches.

2007-03-06 Thread Muli Ben-Yehuda
On Tue, Mar 06, 2007 at 01:09:16AM +0200, guy keren wrote: look at the patch file - it has a very simple general format. i think you can grep for the file names in it, and with little parsing get the list of affected files. Use lsdiff(1) (from the patchutils package) Cheers, Muli

Re: Xen Unstable Seed Repository Tarball

2007-02-05 Thread Muli Ben-Yehuda
On Mon, Feb 05, 2007 at 11:35:05AM +0200, Shlomi Fish wrote: http://www.cl.cam.ac.uk/Research/SRG/netos/xen/downloads/xen-unstable.hg.tar.gz is broken. Where can I find the seed repository tarball instead? No idea. You can just clone the repo. Or - you could ask on the xen-devel mailing list

Re: Kernel question

2007-01-21 Thread Muli Ben-Yehuda
On Mon, Jan 22, 2007 at 01:31:15AM +0200, Hetz Ben Hamo wrote: So, my question is: Why doesn't the kernel automatically select which High memory support to use? After all, if I have 1GB RAM, then it should use the Off. If I have 1GB and =4GB, then it should use the 4GB option, and if I have

Re: IO stats per process

2006-12-27 Thread Muli Ben-Yehuda
On Wed, Dec 27, 2006 at 04:31:02PM +0200, Danny Lieberman wrote: Let's say (for the sake of argument, we do it the io-accounting way - i.e. count cache io) - the numbers will be skewed, but they will be skewed for everyone. I would settle for a io stats per process (similar to sar, perhaps)

Re: [OT][Almost OT] A Cost Analysis of Windows VISTA Content Protection

2006-12-21 Thread Muli Ben-Yehuda
On Thu, Dec 21, 2006 at 10:31:52PM +0200, Ilya Konstantinov wrote: If anything, I was expecting digits showing the performance degradation (if there's anything like that) from running in a hypervisor or with the newfangled IO-MMUs. Funny you should mention that, we're working on a paper on

Re: Ethical question..

2006-11-30 Thread Muli Ben-Yehuda
On Thu, Nov 30, 2006 at 06:29:36PM +0200, Ira Abramov wrote: say you had a client you worked for. One day over lunch, one of the guys of the RD of a different product at the company tells you how they circumvent the kernel checks to load a non-GPL module and get all the symbols a GPL module

Re: How to bind privileged ports in a non-root process?

2006-11-28 Thread Muli Ben-Yehuda
On Tue, Nov 28, 2006 at 10:13:02AM +0200, Shachar Shemesh wrote: Nadav Har'El wrote: So basically, I want to tell linux to allow this process (or any process, for that manner) to bind any port. I tried using capabilities, but didn't get it to work (does anyone know if this feature still

Re: How to bind privileged ports in a non-root process?

2006-11-28 Thread Muli Ben-Yehuda
On Tue, Nov 28, 2006 at 11:43:53AM +0200, Shachar Shemesh wrote: Muli Ben-Yehuda wrote: To answer the original question, I would write a wrapper that uses ptrace to do what's needed, but I'm crazy that way. Hey! I already suggested that! I hope you're not expecting royalties

Re: How to bind privileged ports in a non-root process?

2006-11-28 Thread Muli Ben-Yehuda
On Tue, Nov 28, 2006 at 11:09:07AM +0200, Ilya Konstantinov wrote: You might be able to leave some chosen capability with a non-root process by: 1. Starting as a root process. 2. Eliminating all but the needed capabilities with capset(2) (or whatever higher-level function there is --

Re: How to bind privileged ports in a non-root process?

2006-11-28 Thread Muli Ben-Yehuda
On Tue, Nov 28, 2006 at 12:59:40PM +0200, Muli Ben-Yehuda wrote: On Tue, Nov 28, 2006 at 11:09:07AM +0200, Ilya Konstantinov wrote: You might be able to leave some chosen capability with a non-root process by: 1. Starting as a root process. 2. Eliminating all but the needed

Re: KDE Spell Checking Strangeness

2006-11-22 Thread Muli Ben-Yehuda
On Wed, Nov 22, 2006 at 02:34:14PM +0200, Shlomi Fish wrote: It was indeed unchecked. Once I checked it, kspell recognised the word tipshim as a spelling error. Albeit it suggested tip shim instead of tips him. What's shim? ;-) [EMAIL PROTECTED]:~$ dict shim 4 definitions found From The

Re: Novell and Microsoft

2006-11-09 Thread Muli Ben-Yehuda
On Thu, Nov 09, 2006 at 09:53:41AM -, [EMAIL PROTECTED] wrote: I've read a little about this new deal between Novell and Microsoft. I saw Linux Journal has an article which essentially says everyone should remove SUSE and use some other distribution. Does anyone have a clear view of

Re: swap in Linux

2006-11-05 Thread Muli Ben-Yehuda
On Sun, Nov 05, 2006 at 12:28:41PM +0200, Yahav Biran wrote: My application does from time to time swap. I can see it by monitoring it with vmstat command (si and so parameters). I would like to know why this swap activity was made (lack of memory or memory algorithm). If swap is used it's

Re: swap in Linux

2006-11-05 Thread Muli Ben-Yehuda
On Sun, Nov 05, 2006 at 01:19:29PM +0200, Yahav Biran wrote: [Yahav Biran] I thought that a page can be flush to the disk if nobody is using it for certain amount of time. In Solaris a page fault can happen not only when you are lack of memory. Solaris allocate all its free memory to a

Re: swap in Linux

2006-11-05 Thread Muli Ben-Yehuda
On Sun, Nov 05, 2006 at 02:18:46PM +0200, Yahav Biran wrote: No question on this issue. Regards the spawned sub process, is there a way to view the tree of the process, like ptree in solaris? pstree(1) Cheers, Muli = To

Re: Synchronizing driver with user mode application

2006-10-29 Thread Muli Ben-Yehuda
On Sun, Oct 29, 2006 at 11:17:47AM +0200, Shachar Shemesh wrote: Oron Peled wrote: * aio_* API (in modern 2.6 kernels) A complete sidetracking here. Are you sure it's 2.6 kernels only? The man page lists aio_read under section 3 (library functions), while Advanced Programming in the

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