VM working much better in 2.4.8 than before
I've said it before, I'll say it again - you guys deserve a
'this is a great thing' report once in a while. This is such a report :)
Quoted 1 line
From 2.4.7 to 2.4.8 the greatest effect I've seen so far is that my swap
use is quite minimal - This affects my 486 quite noticably, I don't have exact figures but I'm guessing it's startup time is 1/3 of normal. Shocked the heck out of me, and it's using only 10MB of swap when idle where it used to use at least 15-20MB. Also I've noticed much less swap activity during heavy use, which is really helping both my old 486 in a extremely noticable way (hard disk is a huge bottleneck on that poor demented trashcan :) and my K6-III which has a udma 66 disk... When it doesn't have to pay attention to writing to the swap partition, it obviously can be doing other things. Which helps. Really! :)
Thanks for the improvements, all of you,
Tim McGrath
(formerly at [email protected])
Quoted 3 lines · [email protected] wrote:
I've said it before, I'll say it again - you guys deserve a
'this is a great thing' report once in a while. This is such a report :)
2.4.8 is good indeed. My vmstat window tells me it ties up about 40M less in page cache than earlier kernels, possibly an effect of use-once. (This is a 128M desktop machine.)
updatedb run still manages to use some swap, but the machine is no longer sluggish in the morning. :-)
Helge Hafting
Quoted 11 lines · Helge Hafting
Quoted 3 lines · [email protected] wrote:
I've said it before, I'll say it again - you guys deserve a
'this is a great thing' report once in a while. This is such a report :)2.4.8 is good indeed. My vmstat window tells me it ties up about 40M less in page cache than earlier kernels, possibly an effect of use-once. (This is a 128M desktop machine.)
updatedb run still manages to use some swap, but the machine is no longer sluggish in the morning. :-)
Yes, those would be the expected effects of use-once, in fact it was "morning after updatedb" question that got me started on it.
BTW, keep that 486, it's a great reality check!
--
Daniel
Quoted 2 lines
Yes, those would be the expected effects of use-once, in fact it was "morning after updatedb" question that got me started on it.
updatedb is also absolutely fine if you just work with the existing VM and up the inode pressure a little. I'm still very unconvinced by use-once.
Alan
Quoted 6 lines · Alan Cox
Quoted 2 lines
Yes, those would be the expected effects of use-once, in fact it was "morning after updatedb" question that got me started on it.
updatedb is also absolutely fine if you just work with the existing VM and up the inode pressure a little. I'm still very unconvinced by use-once.
Use-once has a number of theoretical disadvantages too:
1) newly read in pages are evicted earlier, this means readahead pages will either evict each other or the amount of readahead done might need to be shrunk -- the current readahead code is not prepared for this, use-once could lead to more disk seeks being done
2) since we add new pages to the inactive list, VM balancing is faced with a really strange situation ;)
Yes, these things are solvable, but not without redesigning major parts of the VM balancing to do things which have never been done before. I'm not sure 2.4 is the time to do that.
regards,
Rik
--
IA64: a worthy successor to i860.
http://www.surriel.com/ http://distro.conectiva.com/
Send all your spam to [email protected] (spam digging piggy)
Quoted 8 lines · Rik van Riel
Quoted 6 lines · Alan Cox
Quoted 2 lines
Yes, those would be the expected effects of use-once, in fact it was "morning after updatedb" question that got me started on it.
updatedb is also absolutely fine if you just work with the existing VM and up the inode pressure a little. I'm still very unconvinced by use-once.
Quoted 7 lines
Use-once has a number of theoretical disadvantages too:
1) newly read in pages are evicted earlier, this means readahead pages will either evict each other or the amount of readahead done might need to be shrunk -- the current readahead code is not prepared for this, use-once could lead to more disk seeks being done
Have you actually seen this happening?
Quoted 6 lines
2) since we add new pages to the inactive list, VM balancing is faced with a really strange situation ;)
Yes, these things are solvable, but not without redesigning major parts of the VM balancing to do things which have never been done before. I'm not sure 2.4 is the time to do that.
--
Daniel