Messages in this thread | | | Date | Tue, 26 Jun 2007 15:27:30 +0200 | From | Patrick McHardy <> | Subject | Re: [NETFILTER] early_drop() imrovement (v3) |
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Vasily Averin wrote: > Patrick McHardy wrote: >> I don't like the NF_CT_PER_BUCKET constant. First of all, each >> conntrack is hashed twice, so its really only 1/2 of the average >> conntracks per bucket. Secondly, its only a default and many >> people use nf_conntrack_max = nf_conntrack_htable_size / 2, so >> using this constant for early_drop seems wrong. >> >> Perhaps make it 2 * nf_conntrack_max / nf_conntrack_htable_size >> or even add a nf_conntrack_eviction_range sysctl. >> > > IMHO The number of conntracks checked in early_drop() have following restrictions: > - it should be not too low -- to decrease chances of transmission failures, > - it should be limited by some reasonable value -- to prevent long check delays.
Agreed.
> Also I believe it makes sense to have it constant (how about NF_CT_EVICTION > name?) -- to have the same behaviour on various nodes. However I doubt strongly > that anybody will want to change this value. Do you think it is really required? >
I don't know. The current behaviour will on average scan 16 entries. For people manually tuning their hash to saner settings it will scan a single entry. So we have a quite wide range of values already. The single entry with sane hash settings is too little IMO, maybe use some middle-ground, make it 8 by default as you did and rename the constant. NF_CT_EVICTION_RANGE sounds fine.
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