Messages in this thread |  | | Date | Tue, 30 Apr 1996 23:18:59 +0200 | From | "Dr. Werner Fink" <> | Subject | Re: Solved: 1.3.94: open () still slower than 1.2.13 |
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> Date: Fri, 26 Apr 1996 15:47:43 +0300 (EET DST) > From: Linus Torvalds <torvalds@cs.helsinki.fi> > > On Thu, 25 Apr 1996, Pete Harlan wrote: > > > > > How much memory to you have ? > > > Are you sure that everything is cached ? > > > > > > With 1.2.x, your 5517 files will use 5517*2k=11034k > > > With the latest 1.3.x, they will use 5517*4k=22068k... > > > > That was it! Many, many thanks. I reran my tests with 2,800 files > > and 1.3.94 was a weency bit faster than 1.2.13. > > Yes, this is a pretty real problem with the new page cache: the > "allocation block" for the cache is larger than before, and as such the > page cache can be slower than it used to be under 1.2.x. > > I'm afraid that is inevitable - there is a tradeoff here, and overall the > page cache is so much cleaner than the old buffer cache that I'm not > looking back (especially as most of my machines have indecent amounts of > RAM in them considering how much I actually would need). > > This is a real problem for development, actually - most of the people > who test out the development kernels have reasonably high-end hardware, > if only because on low-end hardware it can take longer to compile a > kernel than it takes for me to release a new one ;-). Anyway, that kind > of leads to the kernels getting much more testing on high-end machines. I > hope we're still usable on a 4MB machine ;-/ > > Linus
Is there an easy way to make the amount of the "allocation block" depend on the amount of the pysical memory and/or swap space?
Werner
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