#LyX 1.6.5 created this file. For more info see http://www.lyx.org/\lyxformat 345\begin_document\begin_header\textclass beamer\begin_preamble\usetheme{Warsaw}% or ... \setbeamercovered{transparent}% or whatever (possibly just delete it)\end_preamble\use_default_options false\language english\inputencoding auto\font_roman times\font_sans default\font_typewriter default\font_default_family default\font_sc false\font_osf false\font_sf_scale 100\font_tt_scale 100 \graphics default\paperfontsize default\spacing single\use_hyperref false\papersize default\use_geometry false\use_amsmath 2\use_esint 0\cite_engine basic\use_bibtopic false\paperorientation portrait\secnumdepth 2\tocdepth 2\paragraph_separation indent\defskip medskip\quotes_language english\papercolumns 1\papersides 1\paperpagestyle default\tracking_changes false\output_changes false\author "" \author "" \end_header \begin_body \begin_layout TitleOS bypass performance without OS bypass\begin_inset OptArgstatus open \begin_layout Plain LayoutShort Paper Title\begin_inset Note Notestatus collapsed \begin_layout Plain Layoutoptional, use only with long paper titles\end_layout \end_inset  \end_layout \end_inset  \end_layout \begin_layout DateUsenix 2010\end_layout \begin_layout BeginFrameOutline\end_layout \begin_layout Standard\begin_inset CommandInset tocLatexCommand tableofcontents \end_inset  \end_layout \begin_layout SectionCurrying and process-private system calls\end_layout \begin_layout BeginFrameStandard path\end_layout \begin_layout Standard\begin_inset Graphics	filename ospath.eps	width 80text% \end_inset  \end_layout \begin_layout ItemizeOS overhead known to be primary limit even with very efficient devies\end_layout \begin_layout BeginFrameOS Bypass\end_layout \begin_layout Standard\begin_inset Graphics	filename osbypass.eps	width 80text% \end_inset  \end_layout \begin_layout ItemizeMove Os functionality into the library\end_layout \begin_layout ItemizeAs long as you can relink \emph onevery\emph default program that uses the network, it's fine\end_layout \begin_layout ItemizeAnd single-user\end_layout \begin_layout BeginFramePushing IO back into the kernel via currying and process-private system calls\end_layout \begin_layout Standard\begin_inset Graphics	filename curry.eps	width 80text% \end_inset  \end_layout \begin_layout BeginFrameHow it is used\end_layout \begin_layout Itemizefd = open( \begin_inset Quotes eld\end_inset /dev/torusctl\begin_inset Quotes erd\end_inset )\end_layout \begin_layout Itemizenewsyscall = write(fd, \begin_inset Quotes eld\end_inset fastpath pointer size\begin_inset Quotes erd\end_inset );\end_layout \begin_layout Itemizeparamters and operation \begin_inset Quotes eld\end_inset curried\begin_inset Quotes erd\end_inset  into new system all\end_layout \begin_layout Itemizenewsyscall attached to this process and its children only\end_layout \begin_layout Itemizenewsyscall(); -- no parameters, fast path\end_layout \begin_layout Itemizeno parameters and bypasses all system call checking \end_layout \begin_layout Itemize700 ns measured time on barrier\end_layout \begin_layout ItemizeNow any program, not just mpi programs, can use the network\end_layout \begin_layout ItemizeBeing integrated into new mpi library now\end_layout \begin_layout EndFrame \end_layout \end_body\end_document