[Haifux] ipc
what is the difference between two processes communicating through a normal file discriptor and a fifo pipe discriptor ? p0: mkfifo(myfifo,) int fd=open(myfifo,O_RDONLY..) read(myfifo,buff...) p1: int fd=open(myfifo,O_WRONLY..) write(myfifo,buff) --- p0: int fd=open(file,O_CREAT|O_RDONLY..) read(file,buff...) p0: int fd=open(file,O_WRONLY..) write(file,buff...) is it only the blocking mechanizim ? -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
[Haifux] Xen and the art of giving talks
Dear Haifuxians, Would you care to hear a talk on virtualization, hypervisors and Xen[1][2]? Topics to be covered include a general introduction, design and implementation of Xen, the new Xen 2.0 IO model and future plans. [1] http://www.cl.cam.ac.uk/Research/SRG/netos/xen/index.html [2] A short overview of Xen, from http://www.mulix.org/lectures/OLS2004.html: Xen is a virtual machine monitor, developed by the University of Cambridge Computer Laboratory. Unlike VMWare, which provides complete virtualization, guest operating systems need to be ported to the Xen environment. So far, Linux 2.4 and 2.6 have been ported, as well as NetBSD, FreeBSD and Plan9, and Windows XP. The Windows XP port was done in collaboration with MS Research, and took much longer than the Linux port... Xen works by letting the monitor (hypervisor) run in ring 0, and the guest OS run in ring 1. Userspace runs in ring 3, as usual. From a Linux point of view, porting Linux to Xen (refereed to as XenoLinux) is just a matter of implementing the arch specific hooks in Linux - no core kernel files are modified! Xen provides secure protection between VMs (unlike e.g. coLinux), allows flexible partitioning of resources, and supports seamless low-latency migration of running VMs(!). They also claims impressive performance numbers, within 3% of the host performance. Cheers, Muli -- Muli Ben-Yehuda http://www.mulix.org | http://mulix.livejournal.com/ signature.asc Description: Digital signature
[Haifux] [HAIFUX LECTURE] C Without a Spoon- Programming in C in a free software environment - CPP gcc - Orna Agmon
Next Monday (10/1/2005), 18:30, the Haifa Linux Club will once again meet to hear Orna Agmon talk about: C Without a Spoon Programming in C in a free software environment On this unit we will learn about the CPP - C Pre Processor, and about gcc - the free C compiler, and about using its options cleverly. If time permits, we will start talking about variables in C. (Note that next week's lecture will be by Dorit Naishlos from IBM HRL, about vectorization in gcc.) This is the second of a series of lectures about good C programming in the environment of free software, to people who have already programmed in some language using procedural programming (In other words, we assume you know of some form of the contruct if-then-else, you know what variables and functions/subroutines are). Slides and course material are available at: http://haifux.org/~ladypine/115-sil/ We meet in the Technion, Taub 3. See http://www.haifux.org/where.html for arrival details. Attendance is free, and you are all invited! We are always looking for interesting lecture ideas, and we have already begun scheduling the 2005 season! Future lectures include: 117 gcc and vectorization Dorit Naishlos 17/1/2005 118 SNMP and OpenNMSZeev Halevi 31/01/2005 118-sil C without a spoon Orna Agmon 07/02/2005 119 The VFS of the Linux-2.4 kernel - a play in 5 acts Guy Keren 14/02/2005 Happy St. Valentine's Day! 120 Writing a STAM disk-based file-system for the Linux-2.4 kernel Guy Keren 28/02/2005 Prior understanding required . Have a subject you want to talk about? Or a subject you'd like to hear someone else talk about? email us. Orna. -- Orna Agmon http://haifux.org/~ladypine/ ICQ: 348759096 -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
[Haifux] Test,please ignore
-- Orr Dunkelman, [EMAIL PROTECTED] If it wasn't for C, we'd be writing programs in BASI, PASAL, and OBOL, anon Spammers: http://vipe.technion.ac.il/~orrd/spam.html GPG fingerprint: C2D5 C6D6 9A24 9A95 C5B3 2023 6CAB 4A7C B73F D0AA (This key will never sign Emails, only other PGP keys.) -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
[Haifux] man
when doing man read (for example ) i get in that last line , the usual see also comment where it says :close(2), ...,write(2)...,lseek(2) Q: what is the number following in the parentheses ? (-- 2 in write(2) ) if i do man write it doesn't show info about c language write command so i suppose the number in the parentheses is useful Q : how do i man write(2) ? , hwo do i use the 2 ? -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
[Haifux] man
when doing man read (for example ) i get in that last line , the usual see also comment where it says :close(2), ...,write(2)...,lseek(2) Q: what is the number following in the parentheses ? (-- 2 in write(2) ) if i do man write it doesn't show info about c language write function so i suppose the number in the parentheses is useful Q : how do i man write(2) ? , how do i use the 2 ? -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
Re: [Haifux] Xen and the art of giving talks
yes. On Wed, 12 Jan 2005, Muli Ben-Yehuda wrote: Dear Haifuxians, Would you care to hear a talk on virtualization, hypervisors and Xen[1][2]? Topics to be covered include a general introduction, design and implementation of Xen, the new Xen 2.0 IO model and future plans. [1] http://www.cl.cam.ac.uk/Research/SRG/netos/xen/index.html [2] A short overview of Xen, from http://www.mulix.org/lectures/OLS2004.html: Xen is a virtual machine monitor, developed by the University of Cambridge Computer Laboratory. Unlike VMWare, which provides complete virtualization, guest operating systems need to be ported to the Xen environment. So far, Linux 2.4 and 2.6 have been ported, as well as NetBSD, FreeBSD and Plan9, and Windows XP. The Windows XP port was done in collaboration with MS Research, and took much longer than the Linux port... Xen works by letting the monitor (hypervisor) run in ring 0, and the guest OS run in ring 1. Userspace runs in ring 3, as usual. From a Linux point of view, porting Linux to Xen (refereed to as XenoLinux) is just a matter of implementing the arch specific hooks in Linux - no core kernel files are modified! Xen provides secure protection between VMs (unlike e.g. coLinux), allows flexible partitioning of resources, and supports seamless low-latency migration of running VMs(!). They also claims impressive performance numbers, within 3% of the host performance. Cheers, Muli -- Muli Ben-Yehuda http://www.mulix.org | http://mulix.livejournal.com/ -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
[Haifux] Error in mailing list
Due to some server-side error (my fault for not finding out this earlier), mails sent to haifux in the last few days (since last Friday), miight arrive out-of-order and out-of-date. In case your mail doesn't arrive in the following few hours, please contact me personally, and I'll check to see what happened with your personal message. Sorry. -- Orr Dunkelman, [EMAIL PROTECTED] If it wasn't for C, we'd be writing programs in BASI, PASAL, and OBOL, anon Spammers: http://vipe.technion.ac.il/~orrd/spam.html GPG fingerprint: C2D5 C6D6 9A24 9A95 C5B3 2023 6CAB 4A7C B73F D0AA (This key will never sign Emails, only other PGP keys.) -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
[Haifux] Re: man
On Tuesday 11 January 2005 23:51, yakoub abaya wrote: when doing man read (for example ) i get in that last line , the usual see also comment where it says :close(2), ...,write(2)...,lseek(2) Q: what is the number following in the parentheses ? (-- 2 in write(2) ) This is the section of the man pages to which this man page belongs. The sections are: Section 1 User Commands Section 2 System Calls Section 3 Subroutines Section 4 Devices Section 5 File Formats Section 6 Games Section 7 Miscellaneous Section 8 System Administration Section 9 Kernel Section n New if i do man write it doesn't show info about c language write command so i suppose the number in the parentheses is useful Q : how do i man write(2) ? , hwo do i use the 2 ? man 2 write Regards, Shlomi Fish -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED] -- - Shlomi Fish [EMAIL PROTECTED] Homepage:http://www.shlomifish.org/ Knuth is not God! It took him two days to build the Roman Empire. -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
Re: [Haifux] man
yakoub abaya wrote: when doing man read (for example ) i get in that last line , the usual see also comment where it says :close(2), ...,write(2)...,lseek(2) Q: what is the number following in the parentheses ? (-- 2 in write(2) ) The number is the man section number Sections are: 1 Executable programs or shell commands 2 System calls (functions provided by the kernel) 3 Library calls (functions within program libraries) 4 Special files (usually found in /dev) 5 File formats and conventions eg /etc/passwd 6 Games 7 Miscellaneous (including macro packages and conventions), e.g. man(7), groff(7) 8 System administration commands (usually only for root) 9 Kernel routines [Non standard] if i do man write it doesn't show info about c language write function so i suppose the number in the parentheses is useful Q : how do i man write(2) ? , how do i use the 2 ? do man 2 write -- Ori Idan -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
Re: [Haifux] ipc
yakoub abaya wrote: what is the difference between two processes communicating through a normal file discriptor and a fifo pipe discriptor ? [Transfer by a fifo vs. a shared file] The difference is that the file is stored in the filesystem, and if the processes have a lot to talk about it is wasteful of filesystem space. The blocking part is convenience and simplicity as well, how will the shared file reader know when the other side has some new data in the file? It requires polling and is not efficient in OS resources. A fifo also has semantics that help you, such as atomicity of operations (up to some size of a message) and synchronization of work, the blocking gives you synchronization since the second process won't wake up (and won't waste OS time) until it has data to work on. Baruch -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
Re: [Haifux] Xen and the art of giving talks
yes very much On Wednesday 12 January 2005 11:52, Muli Ben-Yehuda wrote: Dear Haifuxians, Would you care to hear a talk on virtualization, hypervisors and Xen[1][2]? Topics to be covered include a general introduction, design and implementation of Xen, the new Xen 2.0 IO model and future plans. [1] http://www.cl.cam.ac.uk/Research/SRG/netos/xen/index.html [2] A short overview of Xen, from http://www.mulix.org/lectures/OLS2004.html: Xen is a virtual machine monitor, developed by the University of Cambridge Computer Laboratory. Unlike VMWare, which provides complete virtualization, guest operating systems need to be ported to the Xen environment. So far, Linux 2.4 and 2.6 have been ported, as well as NetBSD, FreeBSD and Plan9, and Windows XP. The Windows XP port was done in collaboration with MS Research, and took much longer than the Linux port... Xen works by letting the monitor (hypervisor) run in ring 0, and the guest OS run in ring 1. Userspace runs in ring 3, as usual. From a Linux point of view, porting Linux to Xen (refereed to as XenoLinux) is just a matter of implementing the arch specific hooks in Linux - no core kernel files are modified! Xen provides secure protection between VMs (unlike e.g. coLinux), allows flexible partitioning of resources, and supports seamless low-latency migration of running VMs(!). They also claims impressive performance numbers, within 3% of the host performance. Cheers, Muli -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
Re: [Haifux] man
On Wednesday 12 January 2005 18:04, Ori Idan wrote: yakoub abaya wrote: Q: what is the number following in the parentheses ? (-- 2 in write(2) ) The number is the man section number Sections are: ... Ori, you gave him fish (good ones I must admit), but he need also a fishing pole (AKA RTFM). Each section has an intro man page, so we can run: man 1 intro man 2 intro Q : how do i man write(2) ? , how do i use the 2 ? do man 2 write And even better: man man :-) -- Oron Peled Voice/Fax: +972-4-8228492 [EMAIL PROTECTED] http://www.actcom.co.il/~oron ICQ UIN: 16527398 If I have been able to see farther, it was only because I stood on the shoulders of giants. -- Sir Isaac Newton -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
Re: [Haifux] Xen and the art of giving talks
Yes, Comparisons to other free (Qemu, Bochs,...) and non-free (vmware) are of course welcome... -- Oron Peled Voice/Fax: +972-4-8228492 [EMAIL PROTECTED] http://www.actcom.co.il/~oron ICQ UIN: 16527398 If it's there and you can see it, it's REAL If it's there and you can't see it, it's TRANSPARENT If it's not there and you can see it, it's VIRTUAL If it's not there and you can't see it, it's GONE! -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
[Haifux] module directives ?
i've been reading about driver porting to kerne2.6 the section about block device . they write : static int __init sbd_init(void); __init static void __exit sbd_exit(void); __exit module_init(sbd_init); module_exit(sbd_exit); Q: what is __init and __exit ? are they preprocessor directives ? -- Haifa Linux Club Mailing List (http://www.haifux.org) To unsub send an empty message to [EMAIL PROTECTED]
[Haifux] signal
when doing man signal :
there is :
typdef void (*sighandler_t)(int);
Q:what is this typdef ?, i don't understand it
{ i know that i can provide interrupt handler function
with signal(...,...) }
--
Haifa Linux Club Mailing List (http://www.haifux.org)
To unsub send an empty message to [EMAIL PROTECTED]
Re: [Haifux] module directives ?
On Thu, Jan 13, 2005 at 08:31:30AM +0200, yakoub abaya wrote: i've been reading about driver porting to kerne2.6 the section about block device . they write : static int __init sbd_init(void); __init static void __exit sbd_exit(void); __exit module_init(sbd_init); module_exit(sbd_exit); Q: what is __init and __exit ? are they preprocessor directives ? Yes. They say that this code can be discarded in some cases, to make a slightly smaller kernel. __init says that this is initialization code. Once the kernel or module has finished initializing, it can be discarded. __exit says that this is finalization code. If module unloading is disabled, it can be discarded. Cheers, Muli -- Muli Ben-Yehuda http://www.mulix.org | http://mulix.livejournal.com/ signature.asc Description: Digital signature
Re: [Haifux] signal
On Thu, Jan 13, 2005 at 08:35:20AM +0200, yakoub abaya wrote: when doing man signal : there is : typdef void (*sighandler_t)(int); Q:what is this typdef ?, i don't understand it It says that sighandler_t has the type pointer to a function that accepts an int and returns void. Consult a good C book for more details. Cheers, Muli -- Muli Ben-Yehuda http://www.mulix.org | http://mulix.livejournal.com/ signature.asc Description: Digital signature
