Unw data slow: not by dft. -> must dump to disk

This commit is contained in:
Théophile Bastian 2019-10-19 08:09:22 +02:00
parent 24f53aa0de
commit 21ca3e2605
1 changed files with 9 additions and 7 deletions

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@ -36,9 +36,9 @@
\newcommand{\cmark}{\color{OliveGreen}\ding{52}} \newcommand{\cmark}{\color{OliveGreen}\ding{52}}
\newcommand{\xmark}{\color{BrickRed}\ding{56}} \newcommand{\xmark}{\color{BrickRed}\ding{56}}
\let\tempone\itemize %\let\tempone\itemize
\let\temptwo\enditemize %\let\temptwo\enditemize
\renewenvironment{itemize}{\tempone\addtolength{\itemsep}{0.5\baselineskip}}{\temptwo} %\renewenvironment{itemize}{\tempone\addtolength{\itemsep}{0.5\baselineskip}}{\temptwo}
@ -498,8 +498,8 @@ Segmentation fault.
\item Heuristic to decide whether we index with \reg{rbp} or \item Heuristic to decide whether we index with \reg{rbp} or
\reg{rsp} \reg{rsp}
\end{itemize} \end{itemize}
\item By performing \alert{symbolic execution} with an abstract \item With a \alert{symbolic execution} with an abstract semantics,\\
semantics, we can \alert{synthesize the we can \alert{synthesize the
unwinding table} line by line. unwinding table} line by line.
\item Control flow: forward data-flow analysis \item Control flow: forward data-flow analysis
\item The fixpoints are immediate, cf article \item The fixpoints are immediate, cf article
@ -535,8 +535,10 @@ Segmentation fault.
\pause{} \pause{}
So much that \prog{perf} doesn't use it by default! You must use So much that \prog{perf} cannot unwind online!
\lstbash{perf report --call-graph dwarf} explicitly!
It must \alert{copy to disk the whole call stack} every few instants and
\alert{analyze it later} at report time!
\end{frame} \end{frame}
\sectiontitleframe{} \sectiontitleframe{}