evan_tech -- flush/clear the linux buffer/page cache

11:24 am, 19 Sep 07

flush/clear the linux buffer/page cache

To reset your disk caches on recent Linuxes, see this page. Briefly, to drop everything, echo 3 > /proc/sys/vm/drop_caches . You can run "sync" first to flush dirty pages.

~~The page warns to run "sync" first, which seems a little scary; what I really want is for it to just drop non-dirty pages, so I can benchmark something with a "cold" disk.~~

(Posting this in part because it took me a while to find it, so hopefully that subject will help search engines in the future.)

PS: been playing with git. Holy hell is it fast.

djwatson	git is fast and sexy, except for like, detecting renames and file changelogs and shit. It's fast in the common case, but the uncommon case isn't fast ... which I guess is as it should be.
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Anonymous You're fine without sync, that's if you want to maximize your memory free-up and isn't necessary.

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- evan Thanks for the tip!
  
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  - evan Embarrassing. Only read the second half of the sentence which includes "non-destructive operation and dirty objects are not freeable". Heh.
    
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troworld	The suspend2 (now tux-on-ice) hibernate script has an option to drop caches before hibernating to avoid potentially writing out your entire RAM size to disk. ImageSizeLimit nocache
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Anonymous	You're fine without sync, that's if you want to maximize your memory free-up and isn't necessary.
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evan	Embarrassing. Only read the second half of the sentence which includes "non-destructive operation and dirty objects are not freeable". Heh.
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