Re: [Crash-utility] crash-7.3.2 very long list iteration progressively increasing memory usage

On Tue, 2018-06-26 at 15:34 +0100, Jeremy Harris wrote: > On 06/26/2018 03:29 PM, David Wysochanski wrote: > > On Tue, 2018-06-26 at 09:21 -0400, Dave Anderson wrote: > > > Yes, by default all list entries encountered are put in the built-in > > > hash queue, specifically for the purpose of determining whether there > > > are duplicate entries. So if it's still running, it hasn't found any. > > > > > > To avoid the use of the hashing feature, try entering "set hash off" > > > before kicking off the command. But of course if it finds any, it > > > will loop forever. > > > > > > > Ah ok yeah I forgot about the built-in list loop detection! > > For a storage-less method of list loop-detection: run two walkers > down the list, advancing two versus one elements. If you ever > match the same element location after starting, you have a loop. I agree some algorithm [1] without a hash table may be better especially for larger lists.

I also found that ctrl-c of the very long running crash list command did not release the hash table memory - I had to exit crash for that.

[1] https://en.wikipedia.org/wiki/Cycle_detection -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility