Archiv der Kategorie unix

Linux kernel report

Jonathan Corbet presented a informative presentation about the recent linux kernel work. It was held at the 11′th realtime Linux workshop, and offers some insides and statements not always presented in the normal press, like from 2.6.27 -> 2.6.31++ rough timeframe (October 9, 2008 to September 18, 2009) 48,000 changesets was merged by 2,500 developers and 400 employers. This result is that the kernel grew by 2.5 million lines, or better 140 changesets merged per day and 7267 lines of code added every day. But he also depicts some major functionality added by each version and why it’s needed. paired with some funny pictures a nice walk through. The other papers from the conference are also a good read, take a look at them by yourself

Opensparc internals

Can be found here, (free) Registration is required, but i think this is fair. after briefly describing the history of MLP and CMT they cover the T1,T2 designs and the memory architecture. Following this verification, system evaluation and software tools are the topics. Thanks SUN

Usenix

announced that all online conference proceedings are now freely available to everyone. Awesome! take a look at the proceedings

Brocade to buy foundry :-(

and an impressive demo about what’s possible with javascript

proc/net/netstat monitor

I recently grabbed a little tcl script which you can use for process monitoring. Can’t remember the actual URL where I took it from, and it had no comments in it. Nevertheless, even it’s about a decade ago i worked with tcl, i changed it to print out which TCPext: fields of the netstat command changed. perhaps somebody can use it

#!/usr/bin/tclsh
#
# small utility to print the tcpext. flags that changed.
# Free to use, no warranty etc….
#
# ./mon_linux_netstat
# CTRL-C to stop
#
# Pit 03.07.07

cd /proc/net

set tcp_arr {
TCPEXTFAKE
SyncookiesSent
SyncookiesRecv
SyncookiesFailed
EmbryonicRsts
PruneCalled
RcvPruned
OfoPruned
OutOfWindowIcmps
LockDroppedIcmps
ArpFilter
TW
TWRecycled
TWKilled
PAWSPassive
PAWSActive
PAWSEstab
DelayedACKs
DelayedACKLocked
DelayedACKLost
ListenOverflows
ListenDrops
TCPPrequeued
TCPDirectCopyFromBacklog
TCPDirectCopyFromPrequeue
TCPPrequeueDropped
TCPHPHits
TCPHPHitsToUser
TCPPureAcks
TCPHPAcks
TCPRenoRecovery
TCPSackRecovery
TCPSACKReneging
TCPFACKReorder
TCPSACKReorder
TCPRenoReorder
TCPTSReorder
TCPFullUndo
TCPPartialUndo
TCPDSACKUndo
TCPLossUndo
TCPLoss
TCPLostRetransmit
TCPRenoFailures
TCPSackFailures
TCPLossFailures
TCPFastRetrans
TCPForwardRetrans
TCPSlowStartRetrans
TCPTimeouts
TCPRenoRecoveryFail
TCPSackRecoveryFail
TCPSchedulerFailed
TCPRcvCollapsed
TCPDSACKOldSent
TCPDSACKOfoSent
TCPDSACKRecv
TCPDSACKOfoRecv
TCPAbortOnSyn
TCPAbortOnData
TCPAbortOnClose
TCPAbortOnMemory
TCPAbortOnTimeout
TCPAbortOnLinger
TCPAbortFailed
TCPMemoryPressures
}

#
# read in the values from the netstat file
proc scan_net { _dat} {
upvar $_dat dat
global tcp_arr

set in [open “netstat” “r”]
set l [gets $in]
set l [gets $in]
close $in

set a [split $l ” “]

foreach x $a n $tcp_arr {
if {[string match “TcpExt:” $x]} {
continue
}
set dat($n) $x
#puts “dat von n($n) = $dat($n) ”
}
}

#
# set inital data array and fill it
array set dat {}
scan_net dat

# forever
# sleep 1 second, read in second array
# loop and compare values, if different print the sum
# reset the initial array and copy new to old
while {1} {
after 1000

array set new_dat {}
scan_net new_dat

set somechange 0
foreach a $tcp_arr {
if {[string match “TCPEXTFAKE” $a]} {
continue
}
if {$new_dat($a) != $dat($a)} {
set res [expr {$new_dat($a) - $dat($a)}]
#puts “attribute ‘$a’ from $dat($a) to $new_dat($a) $res”
puts “‘$a’ $res”
set somechange 1
}
}

if {$somechange} {
puts “”
}

array set dat {}
array set dat [array get new_dat]
}

Linux-powered iPhone killer available online in March

will ship at March 11 and cost about US 350. Take a look at the OpenMoko phone

Single core feature phone

Infineon, Comneon, and FSMLabs demonstrated a working prototype of a single-core mobile phone, features look promising, hoping that “be the first at its price point to run Linux” offer finally an affordable handset :-)

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