Description
Sub-command "swap" in crash command doesn't show any info about swap
partition in kernel versions 2.6.28 and above
crash> swap
FILENAME TYPE SIZE USED PCT PRIORITY
crash> q
feastlp4:~ #
Analysis
Swap specific information comes from the kernel data structure
swap_info_struct
.The problem starts when it access the fields of swap_info_struct.
In this case
----------------------
flags = INT(vt->swap_info_struct +
OFFSET(swap_info_struct_flags));
if (!(flags & SWP_USED))
continue; <== Hits this case
----------------------
flags gets value '0' and hence it returns with out calculating swap values
This is happening because post 2.6.28 (precisely commit:
ebebbbe904634b0ca1c674457b399f68db5e05b1) changes flag field in
swap_info_struct from 'int' to 'unsigned long'. flags always gets zero
and jumps further calculation.
Fix
Patch has been attached to this mail
Thanks
Sharyathi
Index: crash-5.0.1/memory.c
===================================================================
--- crash-5.0.1.orig/memory.c 2010-02-17 15:21:24.000000000 -0600
+++ crash-5.0.1/memory.c 2010-04-07 02:20:01.000000000 -0500
@@ -11542,14 +11542,14 @@
dump_swap_info(ulong swapflags, ulong *totalswap_pages, ulong *totalused_pages)
{
int i, j;
- int flags, swap_device, pages, prio, usedswap;
- ulong swap_file, max, swap_map, pct;
+ int swap_device, pages, prio, usedswap, pct;
+ ulong flags, swap_file, max, swap_map;
ulong vfsmnt;
ulong swap_info, swap_info_ptr;
ushort *smap;
ulong inuse_pages, totalswap, totalused;
char buf[BUFSIZE];
@@ -11579,8 +11579,12 @@
} else
fill_swap_info(swap_info);
- flags = INT(vt->swap_info_struct +
- OFFSET(swap_info_struct_flags));
+ if (THIS_KERNEL_VERSION >= LINUX(2,6,28))
+ flags = ULONG(vt->swap_info_struct +
+ OFFSET(swap_info_struct_flags));
+ else
+ flags = INT(vt->swap_info_struct +
+ OFFSET(swap_info_struct_flags));
if (!(flags & SWP_USED))
continue;
@@ -11681,7 +11685,7 @@
pct = (usedswap * 100)/pages;
if (swapflags & VERBOSE)
- fprintf(fp, "%-15s %s %7dk %7dk %2ld%% %d\n",
+ fprintf(fp, "%-15s %s %7dk %7dk %2d%% %d\n",
buf, swap_device ? "PARTITION" : " FILE ",
pages, usedswap, pct, prio);
}
--
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