Michael Schnell wrote: > I understand the Andrei sees the problem in any case, not only with high > rate traffic.
Andrei wrote: >> In my particular case kernel uses all available RAM (~10MB) for disk >> cache and releases it only in ~15 seconds. Other applications cannot Andrei's filling page cache at the rate of ~10MB in 15 seconds. That's what I mean by streaming at a relatively high rate for these sort of devices. No doubt VM tunables can be adjusted in 2.6 to release that page cache faster, but the defaults aren't fast enough. On 2.4.26, I've had similar problems where you have to adjust the "how fast to evict clean page cache" tunable according to which application is running. Too fast eviction and you can't stream video at 1MB/second without stalling. Too slow eviction and it fills up and fragments, which page reclamation isn't good enough to solve. On 2.6 I'd hoped the new VM would adjust the tunable automatically but it sounds, from Andrei's words, that this isn't true in 2.6.24. Some interesting defragmentation heuristics went in since 2.6.24, which is why I suggested he try 2.6.28, but the problem of no-MMU ARM not working in 2.6.28 stopped that. That last thing is why I wonder if there's really anyone using no-MMU ARMs with 2.6 kernels much. Maybe they're all using 2.4, and 2.6 users prefer to target more capable chips? -- Jamie _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
