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authorMauro Carvalho Chehab <mchehab@redhat.com>2013-02-21 13:36:45 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2013-02-21 13:48:45 -0300
commitc7ef7645544131b0750478d1cf94cdfa945c809d (patch)
tree4442e415b365cd43be1d8a73703f809f78177560
parent80cc7d87d5eb34375f916d282450a0906a8ead60 (diff)
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edac: reduce stack pressure by using a pre-allocated buffer
The number of variables at the stack is too big. Reduces the stack usage by using a pre-allocated error buffer. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
-rw-r--r--drivers/edac/edac_mc.c81
-rw-r--r--include/linux/edac.h56
2 files changed, 104 insertions, 33 deletions
diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 34eb9703ed33..4f18dd755939 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -1065,7 +1065,6 @@ static void edac_ue_error(struct mem_ctl_info *mci,
edac_inc_ue_error(mci, enable_per_layer_report, pos, error_count);
}
-#define OTHER_LABEL " or "
/**
* edac_mc_handle_error - reports a memory event to userspace
@@ -1097,19 +1096,28 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
const char *msg,
const char *other_detail)
{
- /* FIXME: too much for stack: move it to some pre-alocated area */
- char detail[80], location[80];
- char label[(EDAC_MC_LABEL_LEN + 1 + sizeof(OTHER_LABEL)) * mci->tot_dimms];
+ char detail[80];
char *p;
int row = -1, chan = -1;
int pos[EDAC_MAX_LAYERS] = { top_layer, mid_layer, low_layer };
- int i;
- long grain;
- bool enable_per_layer_report = false;
+ int i, n_labels = 0;
u8 grain_bits;
+ struct edac_raw_error_desc *e = &mci->error_desc;
edac_dbg(3, "MC%d\n", mci->mc_idx);
+ /* Fills the error report buffer */
+ memset(e, 0, sizeof (*e));
+ e->error_count = error_count;
+ e->top_layer = top_layer;
+ e->mid_layer = mid_layer;
+ e->low_layer = low_layer;
+ e->page_frame_number = page_frame_number;
+ e->offset_in_page = offset_in_page;
+ e->syndrome = syndrome;
+ e->msg = msg;
+ e->other_detail = other_detail;
+
/*
* Check if the event report is consistent and if the memory
* location is known. If it is known, enable_per_layer_report will be
@@ -1132,7 +1140,7 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
pos[i] = -1;
}
if (pos[i] >= 0)
- enable_per_layer_report = true;
+ e->enable_per_layer_report = true;
}
/*
@@ -1146,8 +1154,7 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
* where each memory belongs to a separate channel within the same
* branch.
*/
- grain = 0;
- p = label;
+ p = e->label;
*p = '\0';
for (i = 0; i < mci->tot_dimms; i++) {
@@ -1161,8 +1168,8 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
continue;
/* get the max grain, over the error match range */
- if (dimm->grain > grain)
- grain = dimm->grain;
+ if (dimm->grain > e->grain)
+ e->grain = dimm->grain;
/*
* If the error is memory-controller wide, there's no need to
@@ -1170,8 +1177,13 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
* channel/memory controller/... may be affected.
* Also, don't show errors for empty DIMM slots.
*/
- if (enable_per_layer_report && dimm->nr_pages) {
- if (p != label) {
+ if (e->enable_per_layer_report && dimm->nr_pages) {
+ if (n_labels >= EDAC_MAX_LABELS) {
+ e->enable_per_layer_report = false;
+ break;
+ }
+ n_labels++;
+ if (p != e->label) {
strcpy(p, OTHER_LABEL);
p += strlen(OTHER_LABEL);
}
@@ -1198,12 +1210,12 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
}
}
- if (!enable_per_layer_report) {
- strcpy(label, "any memory");
+ if (!e->enable_per_layer_report) {
+ strcpy(e->label, "any memory");
} else {
edac_dbg(4, "csrow/channel to increment: (%d,%d)\n", row, chan);
- if (p == label)
- strcpy(label, "unknown memory");
+ if (p == e->label)
+ strcpy(e->label, "unknown memory");
if (type == HW_EVENT_ERR_CORRECTED) {
if (row >= 0) {
mci->csrows[row]->ce_count += error_count;
@@ -1216,7 +1228,7 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
}
/* Fill the RAM location data */
- p = location;
+ p = e->location;
for (i = 0; i < mci->n_layers; i++) {
if (pos[i] < 0)
@@ -1226,32 +1238,35 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
edac_layer_name[mci->layers[i].type],
pos[i]);
}
- if (p > location)
+ if (p > e->location)
*(p - 1) = '\0';
/* Report the error via the trace interface */
- grain_bits = fls_long(grain) + 1;
- trace_mc_event(type, msg, label, error_count,
- mci->mc_idx, top_layer, mid_layer, low_layer,
- PAGES_TO_MiB(page_frame_number) | offset_in_page,
- grain_bits, syndrome, other_detail);
+ grain_bits = fls_long(e->grain) + 1;
+ trace_mc_event(type, e->msg, e->label, e->error_count,
+ mci->mc_idx, e->top_layer, e->mid_layer, e->low_layer,
+ PAGES_TO_MiB(e->page_frame_number) | e->offset_in_page,
+ grain_bits, e->syndrome, other_detail);
/* Memory type dependent details about the error */
if (type == HW_EVENT_ERR_CORRECTED) {
snprintf(detail, sizeof(detail),
"page:0x%lx offset:0x%lx grain:%ld syndrome:0x%lx",
- page_frame_number, offset_in_page,
- grain, syndrome);
- edac_ce_error(mci, error_count, pos, msg, location, label,
- detail, other_detail, enable_per_layer_report,
- page_frame_number, offset_in_page, grain);
+ e->page_frame_number, e->offset_in_page,
+ e->grain, e->syndrome);
+ edac_ce_error(mci, e->error_count, pos, e->msg, e->location,
+ e->label, detail, other_detail,
+ e->enable_per_layer_report,
+ e->page_frame_number, e->offset_in_page,
+ e->grain);
} else {
snprintf(detail, sizeof(detail),
"page:0x%lx offset:0x%lx grain:%ld",
- page_frame_number, offset_in_page, grain);
+ page_frame_number, offset_in_page, e->grain);
- edac_ue_error(mci, error_count, pos, msg, location, label,
- detail, other_detail, enable_per_layer_report);
+ edac_ue_error(mci, e->error_count, pos, e->msg, e->location,
+ e->label, detail, other_detail,
+ e->enable_per_layer_report);
}
}
EXPORT_SYMBOL_GPL(edac_mc_handle_error);
diff --git a/include/linux/edac.h b/include/linux/edac.h
index ff18efc754f3..096b7fcdf484 100644
--- a/include/linux/edac.h
+++ b/include/linux/edac.h
@@ -47,8 +47,18 @@ static inline void opstate_init(void)
return;
}
+/* Max length of a DIMM label*/
#define EDAC_MC_LABEL_LEN 31
+/* Maximum size of the location string */
+#define LOCATION_SIZE 80
+
+/* Defines the maximum number of labels that can be reported */
+#define EDAC_MAX_LABELS 8
+
+/* String used to join two or more labels */
+#define OTHER_LABEL " or "
+
/**
* enum dev_type - describe the type of memory DRAM chips used at the stick
* @DEV_UNKNOWN: Can't be determined, or MC doesn't support detect it
@@ -553,6 +563,46 @@ struct errcount_attribute_data {
int layer0, layer1, layer2;
};
+/**
+ * edac_raw_error_desc - Raw error report structure
+ * @grain: minimum granularity for an error report, in bytes
+ * @error_count: number of errors of the same type
+ * @top_layer: top layer of the error (layer[0])
+ * @mid_layer: middle layer of the error (layer[1])
+ * @low_layer: low layer of the error (layer[2])
+ * @page_frame_number: page where the error happened
+ * @offset_in_page: page offset
+ * @syndrome: syndrome of the error (or 0 if unknown or if
+ * the syndrome is not applicable)
+ * @msg: error message
+ * @location: location of the error
+ * @label: label of the affected DIMM(s)
+ * @other_detail: other driver-specific detail about the error
+ * @enable_per_layer_report: if false, the error affects all layers
+ * (typically, a memory controller error)
+ */
+struct edac_raw_error_desc {
+ /*
+ * NOTE: everything before grain won't be cleaned by
+ * edac_raw_error_desc_clean()
+ */
+ char location[LOCATION_SIZE];
+ char label[(EDAC_MC_LABEL_LEN + 1 + sizeof(OTHER_LABEL)) * EDAC_MAX_LABELS];
+ long grain;
+
+ /* the vars below and grain will be cleaned on every new error report */
+ u16 error_count;
+ int top_layer;
+ int mid_layer;
+ int low_layer;
+ unsigned long page_frame_number;
+ unsigned long offset_in_page;
+ unsigned long syndrome;
+ const char *msg;
+ const char *other_detail;
+ bool enable_per_layer_report;
+};
+
/* MEMORY controller information structure
*/
struct mem_ctl_info {
@@ -660,6 +710,12 @@ struct mem_ctl_info {
/* work struct for this MC */
struct delayed_work work;
+ /*
+ * Used to report an error - by being at the global struct
+ * makes the memory allocated by the EDAC core
+ */
+ struct edac_raw_error_desc error_desc;
+
/* the internal state of this controller instance */
int op_state;