From: Jorgen C. <jor...@ce...> - 2001-09-20 12:09:13
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On Wed, Sep 19, 2001 at 14:28:18 -0500, Jeff Dike wrote: > jor...@ce... said: > > Sure. I really need to get the slowdown down to an acceptable level, > > like 2-3x.=20 >=20 > You can see the major problems by ^C-ing UML during this time and looki= ng > at the stack. I bet that 90% of the time, you see fix_range running, a= nd > it's busy remapping the kernel vm when there is no remapping needed. Actually, it's far above 90%. I tried pressing ^C 41 times. 15 times fix_range() was running, and the other 26 times UML was running __munmap(), called from fix_range(). > So, that's the first thing I'd fix. What I have planned is a sequence = number > on kernel vm changes. It'll be stored in a global, and also in each pr= ocess > thread structure. The processes store the last sequence number that th= ey saw. > If a process' sequence number is the same as the global, then fix_range= doesn't > need to look at kernel vm for that process. OK, I'll do my best. VM hacking is new to me, so expect some stupid questions. J=F6rgen |