f



Caching behavior on Linux 2.4.18 for block devices

Hi folks,

On Linux 2.4.18, when a process requests a block that is already in
the block cache, does the kernel map the block cache containing that
block to the requesting process's address space OR copy the content to
the requesting process's address space?

If the answer is the first one, what will happen if >1 processes are
sharing the block cache but 1 of them intends to modify the content?

Thank you!

--Yipkei
0
5/29/2004 5:02:27 AM
comp.os.linux 3406 articles. 0 followers. Post Follow

2 Replies
221 Views

Similar Articles

[PageSpeed] 53

Yipkei Kwok wrote:
> Hi folks,
> 
> On Linux 2.4.18, when a process requests a block that is already in

What did you meant by request? Processes use system calls to talk to the 
kernel.

> the block cache, does the kernel map the block cache containing that
> block to the requesting process's address space OR copy the content to
> the requesting process's address space?
> 
> If the answer is the first one, what will happen if >1 processes are
> sharing the block cache but 1 of them intends to modify the content?


As I know, when process use read system call, kernel always copy 
required contents of one or several blocks from cache to buffer in 
process' adress space. So process can do almost everything with it's buffer.

0
vviruss (55)
5/29/2004 4:30:59 PM
Victor Nazarov wrote:

> Yipkei Kwok wrote:
> 
>> Hi folks,
>>
>> On Linux 2.4.18, when a process requests a block that is already in
> 
> What did you meant by request? Processes use system calls to talk to the 
> kernel.
> 
>> the block cache, does the kernel map the block cache containing that
>> block to the requesting process's address space OR copy the content to
>> the requesting process's address space?
>>
>> If the answer is the first one, what will happen if >1 processes are
>> sharing the block cache but 1 of them intends to modify the content?
> 
> As I know, when process use read system call, kernel always copy 
> required contents of one or several blocks from cache to buffer in 
> process' adress space. So process can do almost everything with it's 
> buffer.

I dunno if the Linux kernel uses it, but there has been in the past (in 
another *nix) a "copy-on-write" flag associated with pages - useful during 
fork(): when a process forks, all pages are mapped into the parent and child 
address spaces and marked as "copy-on-write"; only when either the parent or 
child tries to write is the actual copy made.  [Particularly useful with 
fork() as that's more often than not shortly followed by an exec() which 
would throw away all the just copied pages.]

0
ReapNewsB (1408)
5/29/2004 8:28:15 PM
Reply:

Similar Artilces:

[LINUX] Info: Intel D845GEBV2 mainboard and Linux 2.4.21/2.4.22
I recently had to install Linux on a i845 based system (D845GEBV2 mainboard). In short: Using 2.4.21 and possibly some earlier 2.4 kernels will enrich your system with "DMA timeout" and "hda: lost interrupt" errors. Using 2.4.22 will fix this. -- Mvh. / Best regards, Steen Suder <http://www.suder.dk/> ICQ UIN 4133803 ...

Linux, Linux, Linux
Hi, Interested in trying Linux? Well you came to comp.os.linux.advocacy for some reason, and you probably won't stay long. Here's a list of Linux distributions to choose from. Ubuntu http://www.ubuntu.com Newbie friendly and good support forums. SuSE http://www.novell.com/linux Pay for some support if you're not opposed to spending a little money. Fedora Core http://fedoraproject.org If you're more comfortable with your computer, try this one out. If you get frustrated, don't give up so easy. There is a wealth of information online for whichever distro you choose....

[News] Sabayon GNU/Linux GNOME 4.2 Released, Puppy Linux 4.2 Reviewed
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Sabayon Linux Gnome 4.2 Released ,----[ Quote ] | Sabayon 4.2 will catch you: just the best of the Out-Of-The-Box, GNOME, | multimedia applications and nothing more than what you need for your daily | tasks, but what about your free time? We’ve got it. XBMC (formerly known as | Xbox Media Center) 9.04 is what you’ve ever wanted to build up a fantastic | HTPC or Internet Multimedia Box, so what’s better than having it ready to | use? Show off the new Sabayon Linux to your friends, they have no more | excuses to not try it! `---- http://wgo.wolf911.us/?p=188 Puppy Linux 4.2 – Super Fast Linux – Quick Review and Screenshots ,----[ Quote ] | We reviewed the June 2009 release v.4.2 of Puppy Linux, which comes in a 110 | MB file download from their website, or from accepted mirrors. The iso file | is then burnt to CD and runs as a Live CD. After installing the Live CD into | RAM, I experienced my HP Laptop (2GB RAM) run faster than I’ve ever seen with | any other OS or Linux Distro. `---- http://techexposures.com/2009/06/puppy-linux-4-2-super-fast-linux-quick-review-and-screenshots/ Recent: Sabayon 2009 Roadmap ,----[ Quote ] | Now that we released both 4.1 Gnome and KDE, we started working on next | releases of Sabayon. `---- http://planet.sabayonlinux.org/?p=537 Sabayon Core Sneak Peak ,----[ Quote ] | Lately I have been quite busy with many different (usually sabayon-related) | things. A main focus...

Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs]
Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] - new ! If you have Googled your butt off, and haven't come up with anything ...., and for 14,000 more reasons, please send e-mail, tel4@ath.forthnet.gr, tel2003@pathfinder.gr, astra35@pathfinder.gr, ...

Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs]
Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] - new ! If you have Googled your butt off, and haven't come up with anything ...., and for 14,000 more reasons, please send e-mail, tel4@ath.forthnet.gr, tel2003@pathfinder.gr, astra35@pathfinder.gr, TEL <tel4@ath.forthnet.gr> wrote: > Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat > Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] - > new ! > If you have Googled your butt off, and haven't come up ...

Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] -new !
Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] -new ! If you have Googled your butt off, and haven't come up with anything ...., and for 14,000 more reasons, please send e-mail, tel4@ath.forthnet.gr, tel2003@pathfinder.gr, astra35@pathfinder.gr, ...

Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] -new !
Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] -new ! If you have Googled your butt off, and haven't come up with anything ...., and for 14,000 more reasons, please send e-mail, tel4@ath.forthnet.gr, tel2003@pathfinder.gr, astra35@pathfinder.gr, ...

Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] -new !
Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] -new ! If you have Googled your butt off, and haven't come up with anything ...., and for 14,000 more reasons, please send e-mail, tel4@ath.forthnet.gr, tel2003@pathfinder.gr, astra35@pathfinder.gr, ...

Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs]
Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] - new ! If you have Googled your butt off, and haven't come up with anything ...., and for 14,000 more reasons, please send e-mail, tel4@ath.forthnet.gr, tel2003@pathfinder.gr, astra35@pathfinder.gr, On 29 Nov 2003 04:26:12 -0800, tel4@ath.forthnet.gr (TEL) wrote: > Red Hot Linux v9.0 [2 DVDs]. Red Hot .... what??? is 'Red Hot' [sic] a new distro? .. -- /// Michael J. Tobler: motorcyclist, surfer, skydiver, \\\ \\\ and author: "...

Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs]
Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] - new ! If you have Googled your butt off, and haven't come up with anything ...., and for 14,000 more reasons, please send e-mail, tel4@ath.forthnet.gr, tel2003@pathfinder.gr, astra35@pathfinder.gr, ...

Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] -new !
Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] -new ! If you have Googled your butt off, and haven't come up with anything ...., and for 14,000 more reasons, please send e-mail, tel4@ath.forthnet.gr, tel2003@pathfinder.gr, astra35@pathfinder.gr, ...

Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs]
Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] - new ! If you have Googled your butt off, and haven't come up with anything ...., and for 14,000 more reasons, please send e-mail, tel4@ath.forthnet.gr, tel2003@pathfinder.gr, astra35@pathfinder.gr, ########################################################################## # Send submissions for comp.os.linux.announce to: cola@stump.algebra.com # # PLEASE remember a short description of the software and the LOCATION. # # This group is archived at http://stump.algebra.com/~cola/ # ########################################################################## ...

Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] -new !
Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] -new ! If you have Googled your butt off, and haven't come up with anything ...., and for 14,000 more reasons, please send e-mail, tel4@ath.forthnet.gr, tel2003@pathfinder.gr, astra35@pathfinder.gr, ...

Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs]
Red Hot Linux v9.0 [2 DVDs]. Red Hot Linux v9.0 [3 CDs]. Redhat Enterprise Linux ES v3.0 REPACK [4 CDs]. Mandrake Linux 9.2 [3 CDs] - new ! If you have Googled your butt off, and haven't come up with anything ...., and for 14,000 more reasons, please send e-mail, tel4@ath.forthnet.gr, tel2003@pathfinder.gr, astra35@pathfinder.gr, ...

[News] [Linux] Grafpup 2.00 (Linux) Released, GNOME 2.18.2 Released
Grafpup 2.00 final released ,----[ Quote ] | This release comes with some really bleeding edge features when | compared with previous versions of Grafpup, such as a 2.6.20.2 | kernel, revamped package management with dependency resolution, | Gimp-2.3.14, Cinepaint-0.22 with the cvs Ufraw plug-in, a brand | new control panel, cdrkit replacing cdrtools, Openbox replacing | IceWM, and a host of other changes. `---- http://grafpup.org/news/?p=182 Screenshots: http://grafpup.org/news/?page_id=192 GNOME 2.18.2 released ,----[ Quote ] | The latest release of GNOME is here: GNOME 2.18.2! Thi...

[News] 4 Linux Releases: Foresight Linux 1.1, Ubuntu CE 2.2, Kwort 2.2, Mandriva 2007.1 RC1
Foresight Linux 1.1 is out ! http://foresightlinux.com/downloads/ Kwort [Slackware derivative] 2.2 final released! ,----[ Quote ] | I'm proud to announce that Kwort 2.2 final version has been released | after a very long time (more than a year). The system is very stable | and very usable. `---- http://kwort.org/?page=NewsViewer&ID=45&PHPSESSID=1d286ac69fabebf18b4db27ded0b277d Mandriva Linux 2007 Spring RC1 (aka "Xianyang") ,----[ Quote ] | New since Mandriva Linux 2007: | | * Major desktop components | o KDE 3.5.6 | o GNOME 2.18 (RC: final release will include GNOME 2.18) | o OpenOffice.org 2.1 | o Mozilla Firefox 2.0 `---- http://wiki.mandriva.com/en/Releases/Mandriva/2007.1/Development/RC1 ...

Will new "G5" 1.6 GHz run Linux SuSE Linux 7.3 (2.4.18)?
Will 64-bit IBM Power PC 970 "G5" 1.6 GHz Processor[NL] run Linux SuSE 7.3 (2.4.18)? If anyone has any information on this issue, please do let me know.. Thank you, Leo it comes with os x which is way better IMHO In article <62b2b43f.0310011035.54e683b1@posting.google.com>, Leo <lberdi@hotmail.com> wrote: > Will 64-bit IBM Power PC 970 "G5" 1.6 GHz Processor[NL] run Linux > SuSE 7.3 (2.4.18)? If anyone has any information on this issue, please > do let me know.. > > Thank you, > Leo ...

sleep() API behaves differently in Linux 2.4 and Linux 2.6
Hi, I have a simple program utilizing "sleep()" api to sleep 3 msec periodically. I measured the time difference before calling the api and after it returns back. The same application behaves differently running on Linux 2.4 and 2.6 In Linux 2.6.11, it takes about 3 msec, and running on Linux 2.4.20 it takes about 10 msec. I have attached the program below, many thanks in advance. #include <stdlib.h> #include <stdio.h> #include <sys/types.h> #include <sys/time.h> #include <time.h> #define TO_64(a) (a##LLU) #define kUsecTimeScale TO_6...

Different types of caches used in Linux 2.4 and 2.6!
Hi, I am newbie to Linux Kernel. I am trying to find out the different types of caches used in Linux Kernel. I found out that there are slab cache, page cache, buffer cache, dentry cache, inode cache, SYSV shared memory cache and process mapped virtual memory cache in Linux 2.2. Can u help me in finding out if these are the same caches used in Linux 2.4 and 2.6 or if things have changed in Linux 2.4 and Linux 2.6 ? I am not able to find something concrete on the net on caches in Linux 2.4 and 2.6. Thanks in Advance. "bantu" <naveen.highlander@gmail.com> wrote in message ...

LiS 2.18.2 Released
LiS 2.18.2 was released January 4, 2006. LiS (Linux STREAMS) is a STREAMS framework that is compatible with UNIX SVR 4 STREAMS as described in the "UNIX System V Release 4 Programmer's Guide - STREAMS". The LiS 2.18.2 release is the OpenSS7 Project's http://www.openss7.org/ most recent release of the Linux 2.4 and 2.6 kernel compatible package. It includes libraries, documentation and all the things that needed to run STREAMS for OpenSS7 SS7 packages and other LiS based products. The release is available as a tarball, SRPM and a set of RPMs. See the OpenSS7 Project download page http://www.openss7.org/download.html for the autoconf tarballs. See the OpenSS7 Project STREAMS package page http://www.openss7.org/streams_pkg.html for the tarballs, SRPMs and RPMs. This release suppresses versioning of LiS exported symbols and restores to a large degree binary compatibility of interface functions with LiS 2.18.0; it corrects a few minor errors in the build process, corrects the install-strip target, adds memory versions of io wrappers, lis_printk pataches placed on linux-streams list, HP patches, modifications to putq, putbq, insq, appq; and dejagnu patches. Also, this release includes the pipe performance programs and POSIX conformance test suite used with Linux Fast-STREAMS used for comparison testing between LiS and Linux Fast-STREAMS. These programs were used to generate the comparison performance test results http://www.open...

LiS 2.18.4 Released
Package LiS-2.18.4 was released under GPLv2 2007-01-08. The OpenSS7 Linux STREAMS (LiS) package is an OpenSS7 modified version of the LiS-2.18 package formerly from GCOM, and formerly maintained by David Grothe <dave@gcom.com>. _Note_: The original LiS package from GCOM is no longer actively maintained by either GCOM or the OpenSS7 Project: use the OpenSS7 Linux Fast-STREAMS package <http://www.openss7.org/STREAMS.html> instead. The following are claims made by its authors and original maintainer: The OpenSS7 Modified Linux STREAMS (LiS) package is as STREAMS framework that is compatible with SVR 4 STREAMS. It has lots of debugging features not found in other STREAMS packages. Good to do networking and other things. It allows for installation of binary drivers. Linux STREAMS (LiS) aims to provide SVR 4 compatible STREAMS implementation for Linux and claims to have special debugging facilities; however, the package suffers from the major failings that it is: - no longer maintained; - full of bugs; - incompatible with POSIX; - implements SVR 4 STREAMS rather than the more popular SVR 4.2 MP/ES STREAMS; - portions dubiously licensed under the LGPL; - unsuitable for mainline adoption; - adapts poorly to production kernels; - many SMP races and lockups; - broken 32-bit over 64-bit compatibility; - no strlog(9) STREAMS logger; This is the final release of LiS. There...

[News] Review of SAM Linux 2009, Kongoni Linux, PCLinuxOS 2009.2, and Sabayon 4.2
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 SAM Linux 2009 ,----[ Quote ] | SAM is a pleasant, small LiveCD distribution that doesn't use Gnome or KDE | (although in all fairness XFce does use Gnome libraries). The software | selection is small but covers most of the common themes users will want. `---- http://www.techiemoe.com/tech/sam2009.htm Kongoni Linux ,----[ Quote ] | It's pretty, but I'm not sure how much of that is the work of the maintainers | and how much of it is owed to KDE 4. Their differentiating features, PIG and | KISS, are less than impressive to a ca...

need to migrate from Linux 2.4 to Linux 2.6 kernel, direct replacement of kernel image is Ok?
Currently using one of the leading Embedded Distribution on MIPS core based processor, this Linux is 2.4.20 Kernel, some customers also doing trails with this platform, but some new customers are interested with 2.6 kernel version, can we download 2.6 kernel version from kernel.org and make necessary changes whatever did for 2.4 and replace old kernel file "vmliux.gz.img" with new image, will it be Ok?, not sure how IP address conversion and all migrate, current 2.4 load, we are using dnsmasq package as DHCP/DNS server, which assignes 4 byte IP address on LAN side, any chang...

Peculiar behavior of linux(Linux 2.6.9-42.0.2.EL) tar when moved to xp
I have a cvs repository on linux that I'm moving to xp. When I tar up the files with tar -cvf they seem to be fine. If I do a -tvf on the tar it likewise appears as I would expect it to. When I view the tar file using Winzip or larc a few of the files in the tar seem to have been renamed. These files are mostly java files or xml but the file type doesn't seem to matter. The names change from "filename.java,v" to "filename.java,v0000444". This is consistent though the selection of the files that seem to be renamed is apparently random. Has anyone seen anything...

Web resources about - Caching behavior on Linux 2.4.18 for block devices - comp.os.linux

Behavior - Wikipedia, the free encyclopedia
Behavior or behaviour (see spelling differences ) is the range of actions and mannerisms made by individuals, organisms , systems , or artificial ...

Behavior Design - behaviordesign.com
Behavior designs interactive systems.

Behavior Gap - Exploring the relationship between people and their money. Behavior Gap
Watch it now. Watch the latest videos by Carl Richards on money, emotion, and meaningful conversations.

Dog Behavior Tips -Dog Owners One Stop Shop and Tips
Come and get some free dog behavior tips. Training your new or older dog can sometimes be somewhat of a task if you are new to doing it. Let ...

Modeled Behavior
A quick announcement: we’ve moved the blog to Forbes. You’ll be able to find us there at blogs.forbes.com/modeledbehavior , and soon modeledbehavior.com ...

Online Behavior - Marketing Measurement & Optimization
This website is a source of knowledge for website owners and analysts looking to understand how their online customers behave . But that's not ...

BJ Fogg's Behavior Model
... In addition, he devotes at least half his time to industry projects and innovations, all of which focus on using technology to change behaviors ...

Plant Behavior
The Society of Plant Signaling and Behavior serves the community of scientists interested in sensory plant biology, signaling, information processing ...

Ritualized behavior? Chimps all throw rocks at the same tree
... rocks. “It was unlike anything I had ever observed among wild chimpanzees,” said primatologist Ammie Kalan. Her team has discovered the behavior ...

'The Bachelor' just became the most hated man in ABC history and told 2 women he loves them — and there's ...
"Are you allowed to say that?" "I'm not." That question was the reaction one of the final two women on ABC's hit reality show, "The Bachelor," ...

Resources last updated: 3/8/2016 1:29:21 AM