#7690: maxima stats too many files on startup, which is a performance issue
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Reporter: was | Owner: tbd
Type: defect | Status: new
Priority: blocker | Milestone: sage-4.3.1
Component: packages | Keywords:
Work_issues: | Author:
Upstream: N/A | Reviewer:
Merged: |
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{{{
Hi,
This email is a followup about "1. maxima opens the root directory /
and stats each file found there. Then it does the same thing for the
/u (home) directory..."
Thanks to everybody that responded to my query below. The
"MAXIMA-SHAREDIR" variable looks fine according to the output of
"maxima --directories".
Off list, Andrej Vodopivec remarked "It could be share-subdirs-list in
init-cl.lisp. If that is true, then it should be easy to remove the
call to share-subdirs-list.". I tried doing what Andrej suggested,
and it worked perfectly. Before doing that, Maxima would state about
4000 files (including all users' home directories) on startup, and
afterwards it stat'd only about 70 files. The difference in
performance on some NSF filesystems is huge -- a second versus
potentially *minutes*. Even the difference on
sage.math.washington.edu is quite noticeable (a very fast machine with
a fast network). Looking at the output of makes this very clear:
strace maxima --directories > out 2>&1; grep stat out|wc -l
For now we'll be patching the Maxima in Sage so that
share-subdirs-list (in init-cl.lisp) falls back to the old "default
behavior" instead of the new behavior that was introduced in the
recent rewrite of init-cl.lisp. I really hope whoever rewrote
init-cl.lisp can think about the significant performance regression
that was caused, and find a better solution.
Thanks again for all the incredibly helpful feedback!
-- William
}}}
By the way, what I did to init-cl.lisp was stupid. I changed
{{{
#+ecl
(defun share-subdirs-list ()
;; This doesn't work yet on windows. Give up in that case and use
;; the default list.
(if (string= *autoconf-win32* "true")
}}}
to
{{{
#+ecl
(defun share-subdirs-list ()
;; This doesn't work yet on windows. Give up in that case and use
;; the default list.
(if (string= *autoconf-win32* "false")
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/7690>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
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