[newlib-cygwin/main] Cygwin: faq: add test of fork/exec slowdown by anti-virus
Christian Franke via Cygwin-cvs <[email protected]>
| Newsgroups | gmane.os.cygwin.cvs |
|---|---|
| Message-ID | <[email protected]> |
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=ac28fce85cc4d8f85c2cf10bb52d39f33ec38ed6 commit ac28fce85cc4d8f85c2cf10bb52d39f33ec38ed6 Author: Christian Franke <[email protected]> Date: Sat Mar 29 16:34:33 2025 +0100 Cygwin: faq: add test of fork/exec slowdown by anti-virus Signed-off-by: Christian Franke <[email protected]> Diff: --- winsup/doc/faq-using.xml | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/winsup/doc/faq-using.xml b/winsup/doc/faq-using.xml index 4dc462a0a..e5e4479f5 100644 --- a/winsup/doc/faq-using.xml +++ b/winsup/doc/faq-using.xml @@ -956,6 +956,26 @@ contents are exempt from scanning. In a default installation, this would be <literal>C:\cygwin\bin</literal>. Obviously, this could be exploited by a hostile non-Cygwin program, so do this at your own risk. </para> +<para>Anti-virus software typically reduce the speed of Windows +<literal>CreateProcess</literal> calls which are used by Cygwin to provide +<literal>fork()</literal> and <literal>exec()</literal>. This in particular +slows down shell scripts. In the simple speed test shown below, the first +column shows the number of <literal>date</literal> commands run per second. +Anti-virus was turned off at the line marked with <literal>***</literal>. +</para> +<screen> + bash$ while :; do date +%s; done | uniq -c + ... + 122 1741712430 + 118 1741712431 + 118 1741712432 + 121 1741712433 + 142 1741712434 *** + 140 1741712435 + 141 1741712436 + 144 1741712437 + ... +</screen> <para>See also <xref linkend="faq.using.bloda"></xref> for a list of applications that have been known, at one time or another, to interfere with the normal functioning of Cygwin.