int cfs_cpt_table_print(struct cfs_cpt_table *cptab, char *buf, int len)
{
- char *tmp = buf;
- int rc = -EFBIG;
- int i;
- int j;
+ char *tmp = buf;
+ int rc;
+ int i;
+ int j;
for (i = 0; i < cptab->ctb_nparts; i++) {
if (len <= 0)
- goto out;
+ goto err;
rc = snprintf(tmp, len, "%d\t:", i);
len -= rc;
if (len <= 0)
- goto out;
+ goto err;
tmp += rc;
for_each_cpu(j, cptab->ctb_parts[i].cpt_cpumask) {
rc = snprintf(tmp, len, " %d", j);
len -= rc;
if (len <= 0)
- goto out;
+ goto err;
tmp += rc;
}
tmp++;
len--;
}
- rc = 0;
- out:
- if (rc < 0)
- return rc;
return tmp - buf;
+
+err:
+ return -E2BIG;
}
EXPORT_SYMBOL(cfs_cpt_table_print);
int cfs_cpt_distance_print(struct cfs_cpt_table *cptab, char *buf, int len)
{
- char *tmp = buf;
- int rc = -EFBIG;
- int i;
- int j;
+ char *tmp = buf;
+ int rc;
+ int i;
+ int j;
for (i = 0; i < cptab->ctb_nparts; i++) {
if (len <= 0)
- goto out;
+ goto err;
rc = snprintf(tmp, len, "%d\t:", i);
len -= rc;
if (len <= 0)
- goto out;
+ goto err;
tmp += rc;
for (j = 0; j < cptab->ctb_nparts; j++) {
j, cptab->ctb_parts[i].cpt_distance[j]);
len -= rc;
if (len <= 0)
- goto out;
+ goto err;
tmp += rc;
}
tmp++;
len--;
}
- rc = 0;
- out:
- if (rc < 0)
- return rc;
return tmp - buf;
+
+err:
+ return -E2BIG;
}
EXPORT_SYMBOL(cfs_cpt_distance_print);
return 0;
}
- LASSERT(!cpumask_test_cpu(cpu, cptab->ctb_cpumask));
- LASSERT(!cpumask_test_cpu(cpu, cptab->ctb_parts[cpt].cpt_cpumask));
+ if (cpumask_test_cpu(cpu, cptab->ctb_cpumask)) {
+ CDEBUG(D_INFO, "CPU %d is already in cpumask\n", cpu);
+ return 0;
+ }
+ if (cpumask_test_cpu(cpu, cptab->ctb_parts[cpt].cpt_cpumask)) {
+ CDEBUG(D_INFO, "CPU %d is already in partition %d cpumask\n",
+ cpu, cptab->ctb_cpu2cpt[cpu]);
+ return 0;
+ }
cfs_cpt_add_cpu(cptab, cpt, cpu);
cfs_cpt_add_node(cptab, cpt, cpu_to_node(cpu));
}
} else if (cpt != cptab->ctb_cpu2cpt[cpu]) {
- CDEBUG(D_INFO,
- "CPU %d is not in cpu-partition %d\n", cpu, cpt);
+ CDEBUG(D_INFO, "CPU %d is not in CPU partition %d\n", cpu, cpt);
return;
}
{
int cpu;
- for_each_cpu(cpu, mask)
- cfs_cpt_unset_cpu(cptab, cpt, cpu);
+ for_each_cpu(cpu, mask) {
+ cfs_cpt_del_cpu(cptab, cpt, cpu);
+ cfs_cpt_del_node(cptab, cpt, cpu_to_node(cpu));
+ }
}
EXPORT_SYMBOL(cfs_cpt_unset_cpumask);
int cfs_cpt_set_node(struct cfs_cpt_table *cptab, int cpt, int node)
{
const cpumask_t *mask;
- int cpu;
+ int cpu;
if (node < 0 || node >= nr_node_ids) {
CDEBUG(D_INFO,
int cfs_cpt_set_nodemask(struct cfs_cpt_table *cptab, int cpt,
const nodemask_t *mask)
{
- int i;
+ int node;
- for_each_node_mask(i, *mask) {
- if (!cfs_cpt_set_node(cptab, cpt, i))
- return 0;
- }
+ for_each_node_mask(node, *mask)
+ cfs_cpt_set_node(cptab, cpt, node);
return 1;
}
void cfs_cpt_unset_nodemask(struct cfs_cpt_table *cptab, int cpt,
const nodemask_t *mask)
{
- int i;
+ int node;
- for_each_node_mask(i, *mask)
- cfs_cpt_unset_node(cptab, cpt, i);
+ for_each_node_mask(node, *mask)
+ cfs_cpt_unset_node(cptab, cpt, node);
}
EXPORT_SYMBOL(cfs_cpt_unset_nodemask);
int cfs_cpt_spread_node(struct cfs_cpt_table *cptab, int cpt)
{
- nodemask_t *mask;
- int weight;
- int rotor;
- int node;
+ nodemask_t *mask;
+ int weight;
+ int rotor;
+ int node = 0;
/* convert CPU partition ID to HW node id */
if (cpt < 0 || cpt >= cptab->ctb_nparts) {
- mask = cptab->ctb_nodemask;
+ mask = cptab->ctb_nodemask;
rotor = cptab->ctb_spread_rotor++;
} else {
- mask = cptab->ctb_parts[cpt].cpt_nodemask;
+ mask = cptab->ctb_parts[cpt].cpt_nodemask;
rotor = cptab->ctb_parts[cpt].cpt_spread_rotor++;
+ node = cptab->ctb_parts[cpt].cpt_node;
}
weight = nodes_weight(*mask);
- LASSERT(weight > 0);
+ if (weight > 0) {
+ rotor %= weight;
- rotor %= weight;
-
- for_each_node_mask(node, *mask) {
- if (rotor-- == 0)
- return node;
+ for_each_node_mask(node, *mask) {
+ if (rotor-- == 0)
+ return node;
+ }
}
- LBUG();
- return 0;
+ return node;
}
EXPORT_SYMBOL(cfs_cpt_spread_node);
int cfs_cpt_bind(struct cfs_cpt_table *cptab, int cpt)
{
- cpumask_t *cpumask;
- nodemask_t *nodemask;
- int rc;
- int i;
+ nodemask_t *nodemask;
+ cpumask_t *cpumask;
+ int cpu;
+ int rc;
LASSERT(cpt == CFS_CPT_ANY || (cpt >= 0 && cpt < cptab->ctb_nparts));
nodemask = cptab->ctb_parts[cpt].cpt_nodemask;
}
- if (cpumask_any_and(cpumask, cpu_online_mask) >= nr_cpu_ids) {
- CERROR("No online CPU found in CPU partition %d, did someone "
- "do CPU hotplug on system? You might need to reload "
- "Lustre modules to keep system working well.\n", cpt);
- return -EINVAL;
+ if (!cpumask_intersects(cpumask, cpu_online_mask)) {
+ CDEBUG(D_INFO, "No online CPU found in CPU partition %d, did "
+ "someone do CPU hotplug on system? You might need to "
+ "reload Lustre modules to keep system working well.\n",
+ cpt);
+ return -ENODEV;
}
- for_each_online_cpu(i) {
- if (cpumask_test_cpu(i, cpumask))
+ for_each_online_cpu(cpu) {
+ if (cpumask_test_cpu(cpu, cpumask))
continue;
rc = set_cpus_allowed_ptr(current, cpumask);
* We always prefer to choose CPU in the same core/socket.
*/
static int cfs_cpt_choose_ncpus(struct cfs_cpt_table *cptab, int cpt,
- cpumask_t *node, int number)
+ cpumask_t *node_mask, int number)
{
- cpumask_t *socket = NULL;
- cpumask_t *core = NULL;
+ cpumask_t *socket_mask = NULL;
+ cpumask_t *core_mask = NULL;
int rc = 0;
int cpu;
int i;
LASSERT(number > 0);
- if (number >= cpumask_weight(node)) {
- while (!cpumask_empty(node)) {
- cpu = cpumask_first(node);
+ if (number >= cpumask_weight(node_mask)) {
+ while (!cpumask_empty(node_mask)) {
+ cpu = cpumask_first(node_mask);
+ cpumask_clear_cpu(cpu, node_mask);
+
+ if (!cpu_online(cpu))
+ continue;
rc = cfs_cpt_set_cpu(cptab, cpt, cpu);
if (!rc)
return -EINVAL;
- cpumask_clear_cpu(cpu, node);
}
return 0;
}
/* allocate scratch buffer */
- LIBCFS_ALLOC(socket, cpumask_size());
- LIBCFS_ALLOC(core, cpumask_size());
- if (socket == NULL || core == NULL) {
+ LIBCFS_ALLOC(socket_mask, cpumask_size());
+ LIBCFS_ALLOC(core_mask, cpumask_size());
+ if (socket_mask == NULL || core_mask == NULL) {
rc = -ENOMEM;
goto out;
}
- while (!cpumask_empty(node)) {
- cpu = cpumask_first(node);
+ while (!cpumask_empty(node_mask)) {
+ cpu = cpumask_first(node_mask);
/* get cpumask for cores in the same socket */
- cpumask_copy(socket, topology_core_cpumask(cpu));
- cpumask_and(socket, socket, node);
-
- LASSERT(!cpumask_empty(socket));
-
- while (!cpumask_empty(socket)) {
+ cpumask_and(socket_mask, topology_core_cpumask(cpu), node_mask);
+ while (!cpumask_empty(socket_mask)) {
/* get cpumask for hts in the same core */
- cpumask_copy(core, topology_sibling_cpumask(cpu));
- cpumask_and(core, core, node);
+ cpumask_and(core_mask,
+ topology_sibling_cpumask(cpu), node_mask);
- LASSERT(!cpumask_empty(core));
+ for_each_cpu(i, core_mask) {
+ cpumask_clear_cpu(i, socket_mask);
+ cpumask_clear_cpu(i, node_mask);
- for_each_cpu(i, core) {
- cpumask_clear_cpu(i, socket);
- cpumask_clear_cpu(i, node);
+ if (!cpu_online(i))
+ continue;
rc = cfs_cpt_set_cpu(cptab, cpt, i);
if (!rc) {
if (--number == 0)
goto out;
}
- cpu = cpumask_first(socket);
+ cpu = cpumask_first(socket_mask);
}
}
out:
- if (socket != NULL)
- LIBCFS_FREE(socket, cpumask_size());
- if (core != NULL)
- LIBCFS_FREE(core, cpumask_size());
+ if (core_mask != NULL)
+ LIBCFS_FREE(core_mask, cpumask_size());
+ if (socket_mask != NULL)
+ LIBCFS_FREE(socket_mask, cpumask_size());
return rc;
}
/* generate reasonable number of CPU partitions based on total number
* of CPUs, Preferred N should be power2 and match this condition:
* 2 * (N - 1)^2 < NCPUS <= 2 * N^2 */
- for (ncpt = 2; ncpu > 2 * ncpt * ncpt; ncpt <<= 1) {}
+ for (ncpt = 2; ncpu > 2 * ncpt * ncpt; ncpt <<= 1)
+ ;
if (ncpt <= nnode) { /* fat numa system */
while (nnode > ncpt)
static struct cfs_cpt_table *cfs_cpt_table_create(int ncpt)
{
struct cfs_cpt_table *cptab = NULL;
- cpumask_t *mask = NULL;
+ cpumask_t *node_mask = NULL;
int cpt = 0;
+ int node;
int num;
- int rc;
- int i;
+ int rem;
+ int rc = 0;
- rc = cfs_cpt_num_estimate();
+ num = cfs_cpt_num_estimate();
if (ncpt <= 0)
- ncpt = rc;
+ ncpt = num;
- if (ncpt > num_online_cpus() || ncpt > 4 * rc) {
+ if (ncpt > num_online_cpus() || ncpt > 4 * num) {
CWARN("CPU partition number %d is larger than suggested "
- "value (%d), your system may have performance"
+ "value (%d), your system may have performance "
"issue or run out of memory while under pressure\n",
- ncpt, rc);
- }
-
- if (num_online_cpus() % ncpt != 0) {
- CERROR("CPU number %d is not multiple of cpu_npartition %d, "
- "please try different cpu_npartitions value or"
- "set pattern string by cpu_pattern=STRING\n",
- (int)num_online_cpus(), ncpt);
- goto failed;
+ ncpt, num);
}
cptab = cfs_cpt_table_alloc(ncpt);
if (cptab == NULL) {
CERROR("Failed to allocate CPU map(%d)\n", ncpt);
+ rc = -ENOMEM;
goto failed;
}
- num = num_online_cpus() / ncpt;
- if (num == 0) {
- CERROR("CPU changed while setting CPU partition\n");
- goto failed;
- }
-
- LIBCFS_ALLOC(mask, cpumask_size());
- if (mask == NULL) {
+ LIBCFS_ALLOC(node_mask, cpumask_size());
+ if (node_mask == NULL) {
CERROR("Failed to allocate scratch cpumask\n");
+ rc = -ENOMEM;
goto failed;
}
- for_each_online_node(i) {
- cpumask_copy(mask, cpumask_of_node(i));
-
- while (!cpumask_empty(mask)) {
- struct cfs_cpu_partition *part;
- int n;
-
- /* Each emulated NUMA node has all allowed CPUs in
- * the mask.
- * End loop when all partitions have assigned CPUs.
- */
- if (cpt == ncpt)
- break;
-
- part = &cptab->ctb_parts[cpt];
-
- n = num - cpumask_weight(part->cpt_cpumask);
- LASSERT(n > 0);
-
- rc = cfs_cpt_choose_ncpus(cptab, cpt, mask, n);
- if (rc < 0)
+ num = num_online_cpus() / ncpt;
+ rem = num_online_cpus() % ncpt;
+ for_each_online_node(node) {
+ cpumask_copy(node_mask, cpumask_of_node(node));
+
+ while (cpt < ncpt && !cpumask_empty(node_mask)) {
+ struct cfs_cpu_partition *part = &cptab->ctb_parts[cpt];
+ int ncpu = cpumask_weight(part->cpt_cpumask);
+
+ rc = cfs_cpt_choose_ncpus(cptab, cpt, node_mask,
+ num - ncpu);
+ if (rc < 0) {
+ rc = -EINVAL;
goto failed;
+ }
- LASSERT(num >= cpumask_weight(part->cpt_cpumask));
- if (num == cpumask_weight(part->cpt_cpumask))
+ ncpu = cpumask_weight(part->cpt_cpumask);
+ if (ncpu == num + !!(rem > 0)) {
cpt++;
+ rem--;
+ }
}
}
- if (cpt != ncpt ||
- num != cpumask_weight(cptab->ctb_parts[ncpt - 1].cpt_cpumask)) {
- CERROR("Expect %d(%d) CPU partitions but got %d(%d), "
- "CPU hotplug/unplug while setting?\n",
- cptab->ctb_nparts, num, cpt,
- cpumask_weight(cptab->ctb_parts[ncpt - 1].cpt_cpumask));
- goto failed;
- }
-
- LIBCFS_FREE(mask, cpumask_size());
-
+ LIBCFS_FREE(node_mask, cpumask_size());
return cptab;
- failed:
- CERROR("Failed to setup CPU-partition-table with %d "
- "CPU-partitions, online HW nodes: %d, HW cpus: %d.\n",
- ncpt, num_online_nodes(), num_online_cpus());
+failed:
+ CERROR("Failed (rc=%d) to setup CPU partition table with %d "
+ "partitions, online HW NUMA nodes: %d, HW CPU cores: %d.\n",
+ rc, ncpt, num_online_nodes(), num_online_cpus());
- if (mask != NULL)
- LIBCFS_FREE(mask, cpumask_size());
+ if (node_mask != NULL)
+ LIBCFS_FREE(node_mask, cpumask_size());
if (cptab != NULL)
cfs_cpt_table_free(cptab);
- return NULL;
+ return ERR_PTR(rc);
}
-static struct cfs_cpt_table *
-cfs_cpt_table_create_pattern(char *pattern)
+static struct cfs_cpt_table *cfs_cpt_table_create_pattern(const char *pattern)
{
- struct cfs_cpt_table *cptab;
- char *str;
- int node = 0;
- int ncpt = 0;
- int high;
- int cpt;
- int rc;
- int c;
- int i;
-
- str = cfs_trimwhite(pattern);
- if (*str == 'n' || *str == 'N') {
- pattern = str + 1;
- if (*pattern != '\0') {
- node = 1; /* numa pattern */
+ struct cfs_cpt_table *cptab;
+ char *pattern_dup;
+ char *bracket;
+ char *str;
+ int node = 0;
+ int ncpt = 0;
+ int cpt = 0;
+ int high;
+ int rc;
+ int c;
+ int i;
- } else { /* shortcut to create CPT from NUMA & CPU topology */
+ pattern_dup = kstrdup(pattern, GFP_KERNEL);
+ if (pattern_dup == NULL) {
+ CERROR("Failed to duplicate pattern '%s'\n", pattern);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ str = cfs_trimwhite(pattern_dup);
+ if (*str == 'n' || *str == 'N') {
+ str++; /* skip 'N' char */
+ node = 1; /* NUMA pattern */
+ if (*str == '\0') {
node = -1;
- ncpt = num_online_nodes();
+ for_each_online_node(i) {
+ if (!cpumask_empty(cpumask_of_node(i)))
+ ncpt++;
+ }
}
}
if (ncpt == 0) { /* scanning bracket which is mark of partition */
- for (str = pattern;; str++, ncpt++) {
- str = strchr(str, '[');
- if (str == NULL)
- break;
+ bracket = str;
+ while ((bracket = strchr(bracket, '['))) {
+ bracket++;
+ ncpt++;
}
}
if (ncpt == 0 ||
(node && ncpt > num_online_nodes()) ||
(!node && ncpt > num_online_cpus())) {
- CERROR("Invalid pattern %s, or too many partitions %d\n",
- pattern, ncpt);
- return NULL;
+ CERROR("Invalid pattern '%s', or too many partitions %d\n",
+ pattern_dup, ncpt);
+ rc = -EINVAL;
+ goto err_free_str;
}
cptab = cfs_cpt_table_alloc(ncpt);
if (cptab == NULL) {
- CERROR("Failed to allocate cpu partition table\n");
- return NULL;
+ CERROR("Failed to allocate CPU partition table\n");
+ rc = -ENOMEM;
+ goto err_free_str;
}
if (node < 0) { /* shortcut to create CPT from NUMA & CPU topology */
- cpt = 0;
for_each_online_node(i) {
- if (cpt >= ncpt) {
- CERROR("CPU changed while setting CPU "
- "partition table, %d/%d\n", cpt, ncpt);
- goto failed;
- }
+ if (cpumask_empty(cpumask_of_node(i)))
+ continue;
rc = cfs_cpt_set_node(cptab, cpt++, i);
- if (!rc)
- goto failed;
+ if (!rc) {
+ rc = -EINVAL;
+ goto err_free_table;
+ }
}
+ kfree(pattern_dup);
return cptab;
}
high = node ? nr_node_ids - 1 : nr_cpu_ids - 1;
- for (str = cfs_trimwhite(pattern), c = 0;; c++) {
- struct cfs_range_expr *range;
- struct cfs_expr_list *el;
- char *bracket = strchr(str, '[');
- int n;
+ for (str = cfs_trimwhite(str), c = 0; /* until break */; c++) {
+ struct cfs_range_expr *range;
+ struct cfs_expr_list *el;
+ int n;
+ bracket = strchr(str, '[');
if (bracket == NULL) {
if (*str != 0) {
- CERROR("Invalid pattern %s\n", str);
- goto failed;
+ CERROR("Invalid pattern '%s'\n", str);
+ rc = -EINVAL;
+ goto err_free_table;
} else if (c != ncpt) {
- CERROR("expect %d partitions but found %d\n",
- ncpt, c);
- goto failed;
+ CERROR("Expect %d partitions but found %d\n",
+ ncpt, c);
+ rc = -EINVAL;
+ goto err_free_table;
}
break;
}
if (sscanf(str, "%d%n", &cpt, &n) < 1) {
- CERROR("Invalid cpu pattern %s\n", str);
- goto failed;
+ CERROR("Invalid CPU pattern '%s'\n", str);
+ rc = -EINVAL;
+ goto err_free_table;
}
if (cpt < 0 || cpt >= ncpt) {
CERROR("Invalid partition id %d, total partitions %d\n",
cpt, ncpt);
- goto failed;
+ rc = -EINVAL;
+ goto err_free_table;
}
if (cfs_cpt_weight(cptab, cpt) != 0) {
CERROR("Partition %d has already been set.\n", cpt);
- goto failed;
+ rc = -EPERM;
+ goto err_free_table;
}
str = cfs_trimwhite(str + n);
if (str != bracket) {
- CERROR("Invalid pattern %s\n", str);
- goto failed;
+ CERROR("Invalid pattern '%s'\n", str);
+ rc = -EINVAL;
+ goto err_free_table;
}
bracket = strchr(str, ']');
if (bracket == NULL) {
- CERROR("missing right bracket for cpt %d, %s\n",
- cpt, str);
- goto failed;
+ CERROR("Missing right bracket for partition "
+ "%d in '%s'\n", cpt, str);
+ rc = -EINVAL;
+ goto err_free_table;
}
- if (cfs_expr_list_parse(str, (bracket - str) + 1,
- 0, high, &el) != 0) {
- CERROR("Can't parse number range: %s\n", str);
- goto failed;
+ rc = cfs_expr_list_parse(str, (bracket - str) + 1, 0, high,
+ &el);
+ if (rc) {
+ CERROR("Can't parse number range in '%s'\n", str);
+ rc = -ERANGE;
+ goto err_free_table;
}
list_for_each_entry(range, &el->el_exprs, re_link) {
if ((i - range->re_lo) % range->re_stride != 0)
continue;
- rc = node ? cfs_cpt_set_node(cptab, cpt, i) :
- cfs_cpt_set_cpu(cptab, cpt, i);
+ rc = node ? cfs_cpt_set_node(cptab, cpt, i)
+ : cfs_cpt_set_cpu(cptab, cpt, i);
if (!rc) {
cfs_expr_list_free(el);
- goto failed;
+ rc = -EINVAL;
+ goto err_free_table;
}
}
}
if (!cfs_cpt_online(cptab, cpt)) {
CERROR("No online CPU is found on partition %d\n", cpt);
- goto failed;
+ rc = -ENODEV;
+ goto err_free_table;
}
str = cfs_trimwhite(bracket + 1);
}
+ kfree(pattern_dup);
return cptab;
- failed:
+err_free_table:
cfs_cpt_table_free(cptab);
- return NULL;
+err_free_str:
+ kfree(pattern_dup);
+ return ERR_PTR(rc);
}
#ifdef CONFIG_HOTPLUG_CPU
void cfs_cpu_fini(void)
{
- if (cfs_cpt_table != NULL)
+ if (!IS_ERR_OR_NULL(cfs_cpt_table))
cfs_cpt_table_free(cfs_cpt_table);
#ifdef CONFIG_HOTPLUG_CPU
get_online_cpus();
if (*cpu_pattern != 0) {
- char *cpu_pattern_dup = kstrdup(cpu_pattern, GFP_KERNEL);
-
- if (cpu_pattern_dup == NULL) {
- CERROR("Failed to duplicate cpu_pattern\n");
- goto failed;
- }
-
- cfs_cpt_table = cfs_cpt_table_create_pattern(cpu_pattern_dup);
- kfree(cpu_pattern_dup);
- if (cfs_cpt_table == NULL) {
- CERROR("Failed to create cptab from pattern %s\n",
- cpu_pattern);
+ cfs_cpt_table = cfs_cpt_table_create_pattern(cpu_pattern);
+ if (IS_ERR(cfs_cpt_table)) {
+ CERROR("Failed to create cptab from pattern '%s'\n",
+ cpu_pattern);
+ ret = PTR_ERR(cfs_cpt_table);
goto failed;
}
} else {
cfs_cpt_table = cfs_cpt_table_create(cpu_npartitions);
- if (cfs_cpt_table == NULL) {
- CERROR("Failed to create ptable with npartitions %d\n",
- cpu_npartitions);
+ if (IS_ERR(cfs_cpt_table)) {
+ CERROR("Failed to create cptab with npartitions %d\n",
+ cpu_npartitions);
+ ret = PTR_ERR(cfs_cpt_table);
goto failed;
}
}
put_online_cpus();
- LCONSOLE(0, "HW nodes: %d, HW CPU cores: %d, npartitions: %d\n",
- num_online_nodes(), num_online_cpus(),
- cfs_cpt_number(cfs_cpt_table));
+ LCONSOLE(0, "HW NUMA nodes: %d, HW CPU cores: %d, npartitions: %d\n",
+ num_online_nodes(), num_online_cpus(),
+ cfs_cpt_number(cfs_cpt_table));
return 0;
failed:
git://git.whamcloud.com / fs / lustre-release.git / blobdiff