On 05/26/2011 04:03 PM, Andi Kleen wrote: > On Thu, May 26, 2011 at 03:02:42PM -0400, Josef Bacik wrote: >> + /* >> + * If this dentry needs lookup, don't set the referenced flag so that it >> + * is more likely to be cleaned up by the dcache shrinker in case of >> + * memory pressure. >> + */ >> + if (!d_need_lookup(dentry)) >> + dentry->d_flags |= DCACHE_REFERENCED; > > No it doesn't at all. The allocation will just push everything else > out. > > Really you cannot view this by only looking at the dcache. > You have to look at the complete VM behaviour. All the caches > and the other memory interact. Agreed, but this makes it monumentally easier to push these entries out of the cache, which is the best I can do with what I have for now. >> >> >>> d_alloc uses a normal GFP_KERNEL, which is quite in appropiate for this. >>> >>> It should at least reclaim and probably more, but even then it's >>> risky. >>> >> >> Ah yeah I guess I should have probably used GFP_KERNEL. Sorry about that, > > GFP_KERNEL is already used, but it's wrong. I'm not sure any > of the existing GFP_* flags will give you the semantics you > need in fact. The new flag Minchan added for readahead may come > near, but even that is probably not enough. Yeah if there was a GFP_DONTTRYTOHARD I would use that but there isn't. Maybe I'll code that up. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
