GNU bug report logs - #23717
[PATCH 6/6] grep: do pagesize initialization and buffer allocation earlier

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Zev Weiss <zev <at> bewilderbeest.net>
To: bug-grep <at> gnu.org
Cc: Zev Weiss <zev <at> bewilderbeest.net>
Subject: [PATCH 6/6] grep: do pagesize initialization and buffer allocation
 earlier
Date: Tue,  7 Jun 2016 01:37:43 -0500

* src/grep.c (reset, main): We're going to need pagesize and buffer
initialized anyway, so we might as well do so unconditionally early on
rather than checking on every call to reset().
---
 src/grep.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/src/grep.c b/src/grep.c
index d01bc4f..302e4d7 100644
--- a/src/grep.c
+++ b/src/grep.c
@@ -769,16 +769,6 @@ all_zeros (char const *buf, size_t size)
 static bool
 reset (int fd, struct stat const *st)
 {
-  if (! pagesize)
-    {
-      pagesize = getpagesize ();
-      if (pagesize == 0 || 2 * pagesize + 1 <= pagesize)
-        abort ();
-      bufalloc = (ALIGN_TO (INITIAL_BUFSIZE, pagesize)
-                  + pagesize + sizeof (uword));
-      buffer = xmalloc (bufalloc);
-    }
-
   bufbeg = buflim = ALIGN_TO (buffer + 1, pagesize);
   bufbeg[-1] = eolbyte;
   bufdesc = fd;
@@ -2252,6 +2242,12 @@ main (int argc, char **argv)
   set_program_name (argv[0]);
   program_name = argv[0];
 
+  pagesize = getpagesize ();
+  if (pagesize == 0 || 2 * pagesize + 1 <= pagesize)
+    abort ();
+  bufalloc = (ALIGN_TO (INITIAL_BUFSIZE, pagesize) + pagesize + sizeof (uword));
+  buffer = xmalloc (bufalloc);
+
   keys = NULL;
   keycc = 0;
   with_filenames = false;
-- 
2.8.0.rc3

Message #10 received at 23717-done <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Zev Weiss <zev <at> bewilderbeest.net>
Cc: 23717-done <at> debbugs.gnu.org
Subject: Re: bug#23717: [PATCH 6/6] grep: do pagesize initialization and
 buffer allocation earlier
Date: Sun, 21 Aug 2016 23:28:08 -0700

[Message part 1 (text/plain, inline)]

Thanks, I see this one was also installed in June and so am closing the bug report.

I noticed that the old code and the new both have some glitches with respect to 
large page sizes, so I installed the attached further patch to fix them. I've 
never used grep on a machine with 2 GiB pages, but such beasts exist nowadays 
and we might as well make grep safe for them.

[0001-grep-minor-tweaks-of-initial-buffer-alloc.patch (text/x-diff, attachment)]

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