On 5/9/05, A.M. Fradley <u2amf@xxxxxxxxxxxxx> wrote: > I'd been trying to reduce the amount of page swapping in order to improve the > kernels behaviour during thrashing as a project for my course. I made this > after Arjan van de Ven and Rik van Riel suggested I looked into the swap > tokening mechanism as part of my research. I came up with a function to > measure the swap rate and then to activate/deactivate the token mechanism > depending on how much swapping was being done overall. I think the statistics > I added to the thrash.c file could help it decide how to behave but I'm unsure > how best to use them to do that. > > I've tried testing it a few different ways > but none of them seem to make any difference. I think this is because of my > tests though. I made one program that allocates a linked list, until it is > 128MB long, then once it's done that, it should swap in the oldest page in > order to free the memory and then swap the newest one back in to edit the > pointer to the next node then continue for 2 mins. Then to test how much > progress is made > during the thrashing, I've been running a simple counter program that stops > after minute and I've been comparing the max number reached for the different > attempts I've been making with the kernel. The program for causing thrashing > at least makes it swap pages because I can watch the memory and swap fill up in > system monitor. Running the program to cause thrashing seems to work because > the kernel begins reporting high swap rates when the list reaches the target > length. > > Does anyone know any programs that are designed to test this type of > thing or any comments on the code that I wrote? I'm still new at this, so I've > probably misunderstood/left out some things. The updateSwapRate() fuction is > called at the end of scheduler_tick(). That could probably go somewhere > better. Also, I wasn't sure if changing the value of > swap_token_default_timeout was all I needed to do to reactivate the tokening as > it was disabled in 2.6.11 that I'm working with. > Wouldn't it be better shown in patch form? -- Coywolf Qi Hunt http://sosdg.org/~coywolf/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
