Provided by: libedac-dev_0.18+git12-gd98769e-1build1_amd64 
NAME
libedac - EDAC error reporting library
SYNOPSIS
#include <edac.h>
cc ... -ledac
edac_handle * edac_handle_create (void);
void edac_handle_destroy (edac_handle *edac);
int edac_handle_init (edac_handle *edac);
unsigned int edac_mc_count (edac_handle *edac);
int edac_handle_reset (edac_handle *edac);
int edac_error_totals (edac_handle *edac, struct edac_totals *totals);
edac_mc * edac_next_mc (edac_handle *edac);
int edac_mc_get_info (edac_mc *mc, struct edac_mc_info *info);
edac_mc *edac_next_mc_info (edac_handle *edac,
struct edac_mc_info *info);
int edac_mc_reset (struct edac_mc *mc);
edac_csrow * edac_next_csrow (struct edac_mc *mc);
int edac_csrow_get_info (edac_csrow *csrow,
struct edac_csrow_info *info);
edac_csrow * edac_next_csrow_info (edac_mc *mc,
struct edac_csrow_info *info);
const char * edac_strerror (edac_handle *edac);
edac_for_each_mc_info (edac_handle *edac, edac_mc *mc,
struct edac_csrow_info *info) { ... }
edac_for_each_csrow_info (edac_mc *mc, edac_csrow *csrow,
struct edac_csrow_info *info) { ... }
DESCRIPTION
The libedac library offers a very simple programming interface to the information exported from in-kernel
EDAC (Error Detection and Correction) drivers in sysfs. The edac-util(8) utility uses libedac to report
errors in a user-friendly manner from the command line.
EDAC errors for most systems are recorded in sysfs on a per memory controller (MC) basis. Memory
controllers are further subdivided by csrow and channel. The libedac library provides a method to loop
through multiple MCs, and their corresponding csrows, obtaining information about each component from
sysfs along the way. There is also a simple single call to retrieve the total error counts for a given
machine.
In order to use libedac an edac_handle must first be opened via the call edac_handle_create(). Once the
handle is created, sysfs data can be loaded into the handle with edac_handle_init(). A final call to
edac_handle_destroy() will free all memory and open files associated with the edac handle.
edac_handle_create() will return NULL on failure to allocate memory.
The edac_strerror function will return a descriptive string representation of the last error for the
libedac handle edac.
The edac_error_totals() function will return the total counts of memory and pci errors in the totals
structure passed to the function. The totals structure is of type edac_totals which has the form:
struct edac_totals {
unsigned int ce_total; /* Total corrected errors */
unsigned int ue_total; /* Total uncorrected errors */
unsigned int pci_parity_total; /* Total PCI Parity errors */
};
MEMORY CONTROLLER INFORMATION
Systems may have one or more memory controllers (MCs) with EDAC information. The number of MCs detected
by EDAC drivers may be queried with the edac_mc_count() function, while the edac_next_mc function will
return a handle to the next memory controller in the libedac handle´s internal list. This memory
controller is represented by the opaque edac_mc type.
edac_next_mc will return NULL when there are no further memory controllers to return. Thus the following
example code is another method to count all EDAC MCs (assuming the EDAC library handle edac has already
been initialized):
int i = 0;
edac_mc *mc;
while ((mc = edac_next_mc (edac)))
i++;
return (i);
To query information about an edac_mc, use the edac_mc_get_info function. This function fills in the
given info structure, which is of type edac_mc_info:
struct edac_mc_info {
char id[]; /* Id of memory controller */
char mc_name[]; /* Name of MC */
unsigned int size_mb; /* Amount of RAM in MB */
unsigned int ce_count; /* Corrected error count */
unsigned int ce_noinfo_count;/* noinfo Corrected errors */
unsigned int ue_count; /* Uncorrected error count */
unsigned int ue_noinfo_count;/* noinfo Uncorrected errors*/
};
The function edac_next_mc_info() can be used to loop through all EDAC memory controllers and obtain MC
information in a single call. It is a combined edac_next_mc() and edac_mc_get_info().
The function edac_handle_reset() will reset the internal memory controller iterator in the libedac
handle. A subsequent call to edac_next_mc() would thus return the first EDAC MC.
A convenience macro, edac_for_each_mc_info(), is provided which defines a for loop that iterates through
all memory controller
objects for a given EDAC handle, returning the MC information in the info structure on each iteration.
For example (assuming initialized libedac handle edac):
edac_mc *mc;
struct edac_mc_info info;
int count = 0;
edac_for_each_mc_info (edac, mc, info) {
count++;
printf ("MC info: id=%s name=%s\n", info.id, info.mc_name);
}
CSROW INFORMATION
Each EDAC memory controller may have one or more csrows associated with it. Similar to the MC iterator
functions described above, the edac_next_csrow() function allows libedac users to loop through all csrows
within a given MC. Once the last csrow is reached, the function will return NULL.
The edac_csrow_get_info() function returns information about edac_csrow in the edac_csrow_info structure,
which has the contents:
struct edac_csrow_info {
char id[]; /* CSROW Identity (e.g. csrow0) */
unsigned int size_mb; /* CSROW size in MB */
unsigned int ce_count; /* Total corrected errors */
unsigned int ue_count; /* Total uncorrected errors */
struct edac_channel channel[EDAC_MAX_CHANNELS];
};
struct edac_channel {
int valid; /* Is this channel valid */
unsigned int ce_count; /* Corrected error count */
int dimm_label_valid; /* Is DIMM label valid? */
char dimm_label[]; /* DIMM name */
};
The edac_next_csrow_info() function is a combined version of edac_next_csrow() and edac_csrow_get_info()
for convenience.
The edac_mc_reset() function is provided to reset the edac_mc internal csrow iterator.
A convenience macro, edac_for_each_csrow_info(), is provided which defines a for loop that iterates
through all csrow objects in an EDAC memory controller, returning the csrow information in the info
structure on each iteration.
EXAMPLES
Initialize libedac handle:
edac_handle *edac;
if (!(edac = edac_handle_create ())) {
fprintf (stderr, "edac_handle_create: Out of memory!\n");
exit (1);
}
if (edac_handle_init (edac) < 0) {
fprintf (stderr, "Unable to get EDAC data: %s\n",
edac_strerror (edac));
exit (1);
}
printf ("EDAC initialized with %d MCs\n", edac_mc_count (edac));
edac_handle_destroy (edac);
Report all DIMM labels for MC:csrow:channel combinations
edac_mc *mc;
edac_csrow *csrow;
struct edac_mc_info mci;
struct edac_csrow_info csi;
edac_for_each_mc_info (ctx->edac, mc, mci) {
edac_for_each_csrow_info (mc, csrow, csi) {
char *label[2] = { "unset", "unset" };
if (csi.channel[0].dimm_label_valid)
label[0] = csi.channel[0].dimm_label;
if (csi.channel[1].dimm_label_valid)
label[1] = csi.channel[1].dimm_label;
printf ("%s:%s:ch0 = %s\n", mci.id, csi.id, label[0]);
printf ("%s:%s:ch1 = %s\n", mci.id, csi.id, label[1]);
}
}
SEE ALSO
edac-util(8), edac-ctl(8)
@META_ALIAS 2011-11-09 EDAC(3)