On Monday 26 November 2001 09:28 am, Brian Pane wrote: > The current logic for concatenating small buckets in core_output_filter() > will have performance problems in two cases that I can think of: > > * If you have a brigade consisting of several dozen small buckets, > each one can get copied several times (because we only concatenate > MAX_IOVEC_TO_WRITE of them at at time). > > * If the brigade consists of, say, MAX_IOVEC_TO_WRITE+1 buckets of > size 1MB each, the code will do a huge memory copy to (needlessly) > concatenate the first MAX_IOVEC_TO_WRITE of them. > > My proposed solution is to change the logic as follows: > > * Skip the concatenation if there's >= 8KB of data already > referenced in the iovec.
Do we really concatenate in that case? Whoops, yeah we do. That is a mistake, and should be fixed. > > * Rather than creating a temporary brigade for concatenation, > create a heap bucket. Make it big enough to hold 8KB. Pop > the small buckets from the brigade, concatenate their contents > into the heap bucket, and push the heap bucket onto the brigade. This is exactly what the apr_brigade_write function does. If you stop using that function, you are just duplicating logic. > * If we end up in the concatenation again during the foreach loop > through the brigade, add the small buckets to the end of the > previously allocated heap bucket. If the heap bucket size is > about to exceed 8KB, stop. This should be done by moving the first bucket into a separate brigade and using the brigade_write functions again. Please don't create separate logic to create a buffering bucket, we already have it. Ryan ______________________________________________________________ Ryan Bloom [EMAIL PROTECTED] Covalent Technologies [EMAIL PROTECTED] --------------------------------------------------------------
