Messages in this thread | | | From | Eric Dumazet <> | Subject | Re: [patch] epoll reduced (to 1) number of passes over the ready set ... | Date | Wed, 28 Feb 2007 12:13:59 +0100 |
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On Tuesday 27 February 2007 17:03, Davide Libenzi wrote: > On Tue, 27 Feb 2007, Eric Dumazet wrote: > > On Tuesday 27 February 2007 03:32, Davide Libenzi wrote: > > > Epoll is doing multiple passes over the ready set at the moment, > > > because of the constraints over the f_op->poll() call. Looking at the > > > code again, I noticed that we already hold the epoll semaphore in read, > > > and this (together with other locking conditions that hold while doing > > > an epoll_wait()) can lead to a smarter way to "ship" events to > > > userspace (in a single pass). I added more (even) more comments to the > > > code to explain the conditions why certain operations are safe. > > > This is a stress application that can be used to test the new code. It > > > spwans multiple thread and call epoll_wait() and epoll_ctl() from many > > > threads. Stress tested on my dual Opteron 254 w/out any problems. > > > > Davide, > > > > This is really cool, because the size of epitem would fit now in 128 > > bytes instead of 192 (on x86_64 platforms). So we also reduce memory > > usage. > > Yeah, I forgot to mention that I removed the txlink member.
I am pretty sure you can also remove revents member from epitem.
It would greatly benefit to 32bits platforms, because resulting size would be 64 bytes instead of 68 (so a 50 % reduction because of 64 bytes alignment)
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