[Gfarm-commits] SF.net SVN: gfarm:[6445] gfarm_v2/branches/2.5/lib/libgfarm/gfutil/limit.c

[<n-...@us...>]

Revision: 6445
          http://gfarm.svn.sourceforge.net/gfarm/?rev=6445&view=rev
Author:   n-soda
Date:     2012-07-20 11:53:34 +0000 (Fri, 20 Jul 2012)
Log Message:
-----------
merge r6444 from the main trunk
to fix same problem with it on the 2.5 release branch in r6434
(for #411 - gfmd.conf "metadb_server_max_descriptors" directive to specify descriptor limit):
On a Linux system with very large memory,
sysctl fs.file-max becomes very large too (7338458 in this case).
In that case, setrlimit() fails with EPERM.
Problem pointed out by Jun Ebihara-san.

Revision Links:
--------------
    http://gfarm.svn.sourceforge.net/gfarm/?rev=6444&view=rev
    http://gfarm.svn.sourceforge.net/gfarm/?rev=6434&view=rev

Modified Paths:
--------------
    gfarm_v2/branches/2.5/lib/libgfarm/gfutil/limit.c

Modified: gfarm_v2/branches/2.5/lib/libgfarm/gfutil/limit.c
===================================================================
--- gfarm_v2/branches/2.5/lib/libgfarm/gfutil/limit.c	2012-07-20 11:45:35 UTC (rev 6444)
+++ gfarm_v2/branches/2.5/lib/libgfarm/gfutil/limit.c	2012-07-20 11:53:34 UTC (rev 6445)
@@ -20,6 +20,9 @@
 /*
  * - Set file descriptor limit to min(*file_table_size_p, hard_limit).
  * - Return file descriptor limit to *file_table_size_p.
+ *
+ * NOTE: even if setrlimit() fails, this function returns SUCCESS (== 0),
+ *	because *file_table_sizep will be correctly updated in that case too.
  */
 int
 gfarm_limit_nofiles(int *file_table_size_p)
@@ -27,18 +30,20 @@
 #ifndef HAVE_SETRLIMIT
 	return (EOPNOTSUPP);
 #else
-	struct rlimit limit;
+	struct rlimit old, new;
 	int save_errno, want = *file_table_size_p;
 #ifdef __linux__
 	FILE *fp;
 	unsigned long file_max;
 #endif
 
-	if (getrlimit(RLIMIT_NOFILE, &limit) == -1) {
+	if (getrlimit(RLIMIT_NOFILE, &old) == -1) {
 		save_errno = errno;
 		gflog_warning_errno(GFARM_MSG_1000001, "getrlimit");
 		return (save_errno);
 	}
+	new = old;
+
 #ifdef __linux__
 	/*
 	 * On Linux,
@@ -53,22 +58,36 @@
 			gflog_warning(GFARM_MSG_UNFIXED, "%s: cannot parse",
 			    SYSTEM_FS_FILE_MAX);
 		} else {
-			limit.rlim_max = file_max * (1 - SYSTEM_RESERVE_RATE);
+			file_max *= (1 - SYSTEM_RESERVE_RATE);
+			/*
+			 * fs.file-max may be really large
+			 * (e.g. 7338458 on a machine with large memory),
+			 * and if such large value is set to new.rlim_max,
+			 * setrlimit(2) fails with EPERM.
+			 */
+			new.rlim_max = file_max < want ? file_max : want;
 		}
 		fclose(fp);
 	}
 #endif
-	if (limit.rlim_max != RLIM_INFINITY && want > limit.rlim_max)
-		want = limit.rlim_max;
-	if (limit.rlim_cur != want) {
-		limit.rlim_cur = want;
-		if (setrlimit(RLIMIT_NOFILE, &limit) == -1) {
-			save_errno = errno;
-			gflog_warning_errno(GFARM_MSG_1000002, "setrlimit");
-			return (save_errno);
+	/* `want' will be new.rlim_cur, thus it shouldn't exceed new.rlim_max */
+	if (new.rlim_max != RLIM_INFINITY && want > new.rlim_max)
+		want = new.rlim_max;
+	if (new.rlim_cur != want) {
+		new.rlim_cur = want;
+		if (setrlimit(RLIMIT_NOFILE, &new) == -1) {
+			gflog_warning_errno(GFARM_MSG_UNFIXED,
+			    "setrlimit(RLIMIT_NOFILE) "
+			    "from soft=%llu/hard=%llu "
+			    "to soft=%llu/hard=%llu",
+			    (long long)old.rlim_cur, (long long)old.rlim_max,
+			    (long long)new.rlim_cur, (long long)new.rlim_max);
+			/* log warning, but returns SUCCESS */
+			*file_table_size_p = old.rlim_cur;
+			return(0);
 		}
 	}
-	*file_table_size_p = want;
+	*file_table_size_p = new.rlim_cur;
 	return (0);
 #endif
 }

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