Hello Catalin, Tuesday, June 10, 2014, 4:19:21 PM, you wrote: At first as I said I already forked it: vblade's child: https://sourceforge.net/projects/aoede/ WinAoE: https://sourceforge.net/projects/winaoe/ Brief changes description (including extension negotiation you asked in another message) can be found on Wiki links of both projects. A bit more about AIO and its performance impact. Documentation tells that AIO actually works only with O_DIRECT enabled. This means that if you use AIO for a file descriptor opened without O_DIRECT - operations will be performed synchrnonously and there will be no difference at all with 'usual' read/write. But using O_DIRECT means that file IO will not be cached by Linux kernel that normally makes them much slower. So AIO is reasonable only if you implemented some own caching functionality that is somewhy better than Linux'es (or you dont want caching at all). That approach was good in my usecase - on the system with limited CPU and RAM: at first buffering in userspace seems improved write performance even without using AIO/direct mode. Not sure why, but difference was about twice. Futher using of O_DIRECT and AIO improved write performance even more (obviously due to avoided memory copying between my and OS' caches). Also I implemented read-ahead buffering to keep read performance same good as without O_DIRECT/AIO. Good thing in all this is that such way of using file doesn't bother system-wide cache, and my caching uses very small amount of RAM - 3 megs by default config (may be in more 'thicker' system its reasonable to add buffers - its possible by editing tuneup.h). And even that 3 megs of RAM are freed after 10 seconds of inactivity. About FreeBSD - FreeBSD doesnt support Linux AIO, but there is another AIO, Posix AIO, that a bit different. Linux however supports posix AIO but via 'simulation' - GLib runs userspace threads to perform everything using usual read/write, and performance is discouraging. Also FreeBSD has different implmeentation of socket mapped ring buffer, so in my fork I decided to do not care about FreeBSD, lucky if it still compiles for it :) About WinAoE: I was able to contact its author, and he told me that he dropped project support due to SSD technology that by his opinion eliminated need for AoE: cuz now systems not should be diskless to work noiseless. Anyway, my changes almost doesn't affect networking part, only scheduler was changed and added support for AoEde's features. About your deadlock - I could fixed it.. occasionally :) Its hard to say definately without looking at dump/stack/ CS> Sorry for the delay. I missed this thread. I'd like to chip-in here. CS> @Ed Cashin CS> I slightly disagree with the need to fork this. I believe it should go CS> into the contrib folder, should it be kept up to date. CS> The previous AIO patch is documented to have offered negligible CS> improvements on Linux at that time. CS> I contacted the patch writer some time ago and enquired about the CS> results. As I recall, it also offered similarly disappointing results on CS> FreeBSD (but then again the old code did not use jumbo-frames) CS> Dropping the new code in the contrib folder as a patch sounds better to CS> me (and maybe if it is sufficiently stable, maintainers might wish to CS> include it in distributions) -- Best regards, Killer{R} mailto:support@xxxxxxxxxxxx ------------------------------------------------------------------------------ HPCC Systems Open Source Big Data Platform from LexisNexis Risk Solutions Find What Matters Most in Your Big Data with HPCC Systems Open Source. Fast. Scalable. Simple. Ideal for Dirty Data. Leverages Graph Analysis for Fast Processing & Easy Data Exploration http://p.sf.net/sfu/hpccsystems _______________________________________________ Aoetools-discuss mailing list Aoetools-discuss@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/aoetools-discuss
