[9fans] Problem with outputing from kernel
I added some logs in /sys/src/9/port/proc.c for some tests of the scheduler, I want to see at what moments do real time processes take the cpu. I did that with simple prints with the intention of doing cat /dev/kmesg > someFile because all the prints are stored there. The problem is that the flow of output just randomly stops at times and continues(only once by test) and i lose some of the output which is really important. Any ideas why? Also I was doing with tail -f /dev/kmesg in the background and without that /dev/kmesg loses the start of output up to some random moment where it shows it. Could the problem be that i have too many outputs? -- 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/T31db04ef89737d25-Ma028dd0e821a763795e71625 Delivery options: https://9fans.topicbox.com/groups/9fans/subscription
Re: [9fans] Problem with outputing from kernel
Quoth dusan3...@gmail.com: > I added some logs in /sys/src/9/port/proc.c for some tests of the scheduler, > I want to see at what moments do real time processes take the cpu. I did that > with simple prints with the intention of doing cat /dev/kmesg > someFile > because all the prints are stored there. > > The problem is that the flow of output just randomly stops at times and > continues(only once by test) and i lose some of the output which is really > important. Any ideas why? are you printing from an interrupt context? use iprint for that. also, are you looking for trace(1)? we ship with a tool for showing scheduler decisions. > > Also I was doing with tail -f /dev/kmesg in the background and without that > /dev/kmesg loses the start of output up to some random moment where it shows > it. Could the problem be that i have too many outputs? that's what tail *does*. It shows the tail (by default, last 10 lines) of the file. -- 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/T31db04ef89737d25-M5f99acee5813b799ce86afe6 Delivery options: https://9fans.topicbox.com/groups/9fans/subscription
Re: [9fans] Problem with outputing from kernel
On Wed, Oct 04, 2023 at 07:18:23AM -0400, dusan3...@gmail.com wrote: > Also I was doing with tail -f /dev/kmesg in the background and without that > /dev/kmesg loses the start of output up to some random moment where it shows > it. Could the problem be that i have too many outputs? try tail +0f /dev/kmesg -- 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/T31db04ef89737d25-M0e9be2ef226b9b14bee99193 Delivery options: https://9fans.topicbox.com/groups/9fans/subscription
Re: [9fans] Problem with outputing from kernel
https://9p.io/wiki/plan9/avoiding_screen_pollution_from_kernel_messages/index.html this helped -- 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/T31db04ef89737d25-M6bbf54d0c44e0b1751ec3632 Delivery options: https://9fans.topicbox.com/groups/9fans/subscription