Messages in this thread | | | From | "Dolkow, Snild" <> | Date | Mon, 15 Apr 2013 20:28:07 +0200 | Subject | RE: [PATCH] lowmemorykiller: prevent multiple instances of low memory killer |
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>> > >From the comments in shrinker.h: >> > "It should return the number of objects which remain in the cache. >> > If it returns -1, it means it cannot do any scanning at this time >> > (eg. there is a risk of deadlock). The callback must not return -1 >> > if nr_to_scan is zero." >> > >IMO one should use the errno.h values - e.g. EBUSY might be a good value >in this case. Does anyone know why the shrinker wants -1? Is there a >reason?
The positive numbers are used to return information on the remaining cache size (again, see the comment I pasted above). We could use -EBUSY, but we'd have to change vmscan.c, which checks specifically for -1. I can't see a technical reason why -EBUSY couldn't have been chosen instead, but there's also no real reason to change it now.
//Snild
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