[PATCH] maint: cleanup size determination in sort [was: overly aggressive memory usage by sort.c]

[Bernhard Voelker]

On 06/11/2012 07:24 PM, Paul Eggert wrote:
> On 06/11/2012 01:47 PM, Voelker, Bernhard wrote:
>> Am I wrong?
> 
> I think so.  The newly inserted code
> "if (total * 0.75 < size) size = total * 0.75;"
> is independent of the limits affected by
> the ulimit and plimit commands.  In your example
> 'sort' will consume 4 * 15/16 GB if physmem_available
> reports 4 GB available.

Thanks for the clarification. I was confused.

Here's a patch to move the code regarding physical/available/total
memory down to where it's used (on top of your patch).

Have a nice day,
Berny


>From 1957c9a46e0427b2bbb346c2cb29710e7cbd6182 Mon Sep 17 00:00:00 2001
From: Bernhard Voelker <address@hidden>
Date: Thu, 14 Jun 2012 07:54:34 +0200
Subject: [PATCH] maint: cleanup size determination in sort

* src/sort.c (default_sort_size): Move physmem code "down" to first use.
---
 src/sort.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/sort.c b/src/sort.c
index f21e092..c0d0c84 100644
--- a/src/sort.c
+++ b/src/sort.c
@@ -1405,11 +1405,6 @@ specify_nthreads (int oi, char c, char const *s)
 static size_t
 default_sort_size (void)
 {
-  /* Let MEM be available memory or 1/8 of total memory, whichever
-     is greater.  */
-  double avail = physmem_available ();
-  double total = physmem_total ();
-  double mem = MAX (avail, total / 8);
   struct rlimit rlimit;

   /* Let SIZE be MEM, but no more than the maximum object size,
@@ -1435,6 +1430,12 @@ default_sort_size (void)
     size = rlimit.rlim_cur / 16 * 15;
 #endif

+  /* Let MEM be available memory or 1/8 of total memory, whichever
+     is greater.  */
+  double avail = physmem_available ();
+  double total = physmem_total ();
+  double mem = MAX (avail, total / 8);
+
   /* Similarly, leave a 1/4 margin for physical memory.  */
   if (total * 0.75 < size)
     size = total * 0.75;
-- 
1.7.7