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List:       kde-commits
Subject:    KDE/kdebase/workspace/ksysguard/ksysguardd/Linux
From:       John Tapsell <john.tapsell () kdemail ! net>
Date:       2009-08-25 22:24:47
Message-ID: 1251239087.285901.15211.nullmailer () svn ! kde ! org
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SVN commit 1015584 by johnflux:

Forwardport r801043 from 3.5 branch, it somehow got lost.

"While the internal buffer /proc/cpuinfo is read into is 32k is size, reading
these 32k in a single chunk is not possible: Only up to a page wort of
information is being returned in a single read (reading stops as soon as the
full block for a subsequent CPU wouldn't fit into the buffer space remaining in
the page anymore). The effect is that only 5 or 6 CPUs (depending on the exact
size info for one CPU has) get their frequency displayed (and the respective
sensor offered for selection) on x86/x86-64 (where the page size is 4k).
Consequently, multiple reads (until zero bytes are read) must be issued to
obtain all information."

 M  +18 -7     cpuinfo.c  


--- trunk/KDE/kdebase/workspace/ksysguard/ksysguardd/Linux/cpuinfo.c #1015583:1015584
@@ -171,13 +171,24 @@
         return -1;
     }
 
-    n = read( fd, CpuInfoBuf, CPUINFOBUFSIZE - 1 );
-    if ( n == CPUINFOBUFSIZE - 1 || n <= 0 ) {
-        log_error( "Internal buffer too small to read \'/proc/cpuinfo\'" );
-        CpuInfoOK = 0;
-
-        close( fd );
-        return -1;
+    n = 0;
+    for(;;) {
+        ssize_t len = read( fd, CpuInfoBuf + n, CPUINFOBUFSIZE - 1 - n );
+        if( len < 0 ) {
+            print_error( "Failed to read file \'/proc/cpuinfo\'!\n" );
+            CpuInfoOK = -1;
+            close( fd );
+            return -1;
+        }
+        n += len;
+        if( len == 0 ) /* reading finished */
+            break;
+        if( n == CPUINFOBUFSIZE - 1 ) {
+            log_error( "Internal buffer too small to read \'/proc/cpuinfo\'" );
+            CpuInfoOK = 0;
+            close( fd );
+            return -1;
+        }
     }
 
     close( fd );
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