On Mon, 23 Jul 2012 20:45:17 +0400 Alexander Polakov <p...@sdf.org> wrote:
> This diff reduces IPI traffic for a case when process A is sending > a lot of signals to process B running on a different CPU. userret() > delivers all process signals at once, so there is no need to send > an interrupt for every signal. > > The problem was noticed by rtorrent 0.9.2 users, which does exactly > this, which led to process/system hangs and slowness. > > Tested and known to help on amd64 by me and dcoppa@. Hi Alexander and tech, I've tried this on i386-current built July 25, building ports of rtorrent 0.9.2 and libtorrent 13.2 (instead of the reverted versions). With upload and download rates between 40-50k in each direction, systat reports ipi between 13 and 5696 prior to this patch being applied (on a June 25th -current). The ipi sits between 10 and 82 with this patch. The keyboard navigation in the rtorrent ncurses interface seems a bit more responsive, too. Brett.
