Re: [PATCH] fix sys cpumap for > 352 NR_CPUS

[Paul Jackson <pj@sgi.com>]

This patch (fix-sys-cpumap-for-352-nr_cpus) doesn't work.  Passing -1UL
to cpumask_scnprintf() suppresses all of the requested output, because
of the following code in lib/vsprintf.c vsnprintf():

        /* Reject out-of-range values early */
        if (unlikely((int) size < 0)) {
                /* There can be only one.. */
                static int warn = 1;
                WARN_ON(warn);
                warn = 0;
                return 0;
        }

Using PAGE_SIZE works ok.  Well, lets throw in a -1 to leave a slot for
the newline, while we're here.

Signed-off-by: Paul Jackson <pj@sgi.com>

Index: 2.6.7-rc2-mm2/drivers/base/node.c
===================================================================
--- 2.6.7-rc2-mm2.orig/drivers/base/node.c	2004-06-03 08:24:19.000000000 -0700
+++ 2.6.7-rc2-mm2/drivers/base/node.c	2004-06-03 08:26:12.000000000 -0700
@@ -24,7 +24,7 @@ static ssize_t node_read_cpumap(struct s
 	/* 2004/06/03: buf currently PAGE_SIZE, need > 1 char per 4 bits. */
 	BUILD_BUG_ON(NR_CPUS/4 > PAGE_SIZE/2);
 
-	len = cpumask_scnprintf(buf, -1UL, mask);
+	len = cpumask_scnprintf(buf, PAGE_SIZE-1, mask);
 	len += sprintf(buf + len, "\n");
 	return len;
 }


-- 
                          I won't rest till it's the best ...
                          Programmer, Linux Scalability
                          Paul Jackson <pj@sgi.com> 1.650.933.1373