kern/kmem: rework the info functions

Directly use existing caches instead of copying them to temporary
storage (the idea was to reduce contention but these functions are so
infrequently used that it's actually irrelevant). Also, wrap the dozen
printk calls into one.

1 files changed, 37 insertions, 75 deletions

diff --git a/kern/kmem.c b/kern/kmem.c
index af3eccac..2718c09e 100644
--- a/kern/kmem.c
+++ b/kern/kmem.c
@@ -1027,7 +1027,6 @@ slab_free:
 void
 kmem_cache_info(struct kmem_cache *cache)
 {
-    struct kmem_cache *cache_stats;
     char flags_str[64];
 
     if (cache == NULL) {
@@ -1041,55 +1040,36 @@ kmem_cache_info(struct kmem_cache *cache)
         return;
     }
 
-    cache_stats = kmem_alloc(sizeof(*cache_stats));
-
-    if (cache_stats == NULL) {
-        printk("kmem: unable to allocate memory for cache stats\n");
-        return;
-    }
+    snprintf(flags_str, sizeof(flags_str), "%s%s%s",
+        (cache->flags & KMEM_CF_DIRECT) ? " DIRECT" : "",
+        (cache->flags & KMEM_CF_SLAB_EXTERNAL) ? " SLAB_EXTERNAL" : "",
+        (cache->flags & KMEM_CF_VERIFY) ? " VERIFY" : "");
 
     /* mutex_lock(&cache->mutex); */
-    cache_stats->flags = cache->flags;
-    cache_stats->obj_size = cache->obj_size;
-    cache_stats->align = cache->align;
-    cache_stats->buf_size = cache->buf_size;
-    cache_stats->bufctl_dist = cache->bufctl_dist;
-    cache_stats->slab_size = cache->slab_size;
-    cache_stats->color_max = cache->color_max;
-    cache_stats->bufs_per_slab = cache->bufs_per_slab;
-    cache_stats->nr_objs = cache->nr_objs;
-    cache_stats->nr_bufs = cache->nr_bufs;
-    cache_stats->nr_slabs = cache->nr_slabs;
-    cache_stats->nr_free_slabs = cache->nr_free_slabs;
-    strcpy(cache_stats->name, cache->name);
-    cache_stats->buftag_dist = cache->buftag_dist;
-    cache_stats->redzone_pad = cache->redzone_pad;
-    cache_stats->cpu_pool_type = cache->cpu_pool_type;
-    /* mutex_unlock(&cache->mutex); */
 
-    snprintf(flags_str, sizeof(flags_str), "%s%s%s",
-        (cache_stats->flags & KMEM_CF_DIRECT) ? " DIRECT" : "",
-        (cache_stats->flags & KMEM_CF_SLAB_EXTERNAL) ? " SLAB_EXTERNAL" : "",
-        (cache_stats->flags & KMEM_CF_VERIFY) ? " VERIFY" : "");
-
-    printk("kmem: name: %s\n", cache_stats->name);
-    printk("kmem: flags: 0x%x%s\n", cache_stats->flags, flags_str);
-    printk("kmem: obj_size: %zu\n", cache_stats->obj_size);
-    printk("kmem: align: %zu\n", cache_stats->align);
-    printk("kmem: buf_size: %zu\n", cache_stats->buf_size);
-    printk("kmem: bufctl_dist: %zu\n", cache_stats->bufctl_dist);
-    printk("kmem: slab_size: %zu\n", cache_stats->slab_size);
-    printk("kmem: color_max: %zu\n", cache_stats->color_max);
-    printk("kmem: bufs_per_slab: %lu\n", cache_stats->bufs_per_slab);
-    printk("kmem: nr_objs: %lu\n", cache_stats->nr_objs);
-    printk("kmem: nr_bufs: %lu\n", cache_stats->nr_bufs);
-    printk("kmem: nr_slabs: %lu\n", cache_stats->nr_slabs);
-    printk("kmem: nr_free_slabs: %lu\n", cache_stats->nr_free_slabs);
-    printk("kmem: buftag_dist: %zu\n", cache_stats->buftag_dist);
-    printk("kmem: redzone_pad: %zu\n", cache_stats->redzone_pad);
-    printk("kmem: cpu_pool_size: %d\n", cache_stats->cpu_pool_type->array_size);
-
-    kmem_free(cache_stats, sizeof(*cache_stats));
+    printk("kmem: name: %s\n"
+           "kmem: flags: 0x%x%s\n"
+           "kmem: obj_size: %zu\n"
+           "kmem: align: %zu\n"
+           "kmem: buf_size: %zu\n"
+           "kmem: bufctl_dist: %zu\n"
+           "kmem: slab_size: %zu\n"
+           "kmem: color_max: %zu\n"
+           "kmem: bufs_per_slab: %lu\n"
+           "kmem: nr_objs: %lu\n"
+           "kmem: nr_bufs: %lu\n"
+           "kmem: nr_slabs: %lu\n"
+           "kmem: nr_free_slabs: %lu\n"
+           "kmem: buftag_dist: %zu\n"
+           "kmem: redzone_pad: %zu\n"
+           "kmem: cpu_pool_size: %d\n", cache->name, cache->flags, flags_str,
+           cache->obj_size, cache->align, cache->buf_size, cache->bufctl_dist,
+           cache->slab_size, cache->color_max, cache->bufs_per_slab,
+           cache->nr_objs, cache->nr_bufs, cache->nr_slabs,
+           cache->nr_free_slabs, cache->buftag_dist, cache->redzone_pad,
+           cache->cpu_pool_type->array_size);
+
+    /* mutex_unlock(&cache->mutex); */
 }
 
 void __init
@@ -1248,47 +1228,29 @@ kmem_free(void *ptr, size_t size)
 void
 kmem_info(void)
 {
-    struct kmem_cache *cache, *cache_stats;
+    struct kmem_cache *cache;
     size_t mem_usage, mem_reclaimable;
 
-    cache_stats = kmem_alloc(sizeof(*cache_stats));
-
-    if (cache_stats == NULL) {
-        printk("kmem: unable to allocate memory for cache stats\n");
-        return;
-    }
-
     printk("kmem: cache                  obj slab  bufs   objs   bufs "
-           "   total reclaimable\n");
-    printk("kmem: name                  size size /slab  usage  count "
+           "   total reclaimable\n"
+           "kmem: name                  size size /slab  usage  count "
            "  memory      memory\n");
 
     /* mutex_lock(&kmem_cache_list_mutex); */
 
     list_for_each_entry(&kmem_cache_list, cache, node) {
         /* mutex_lock(&cache->mutex); */
-        cache_stats->obj_size = cache->obj_size;
-        cache_stats->slab_size = cache->slab_size;
-        cache_stats->bufs_per_slab = cache->bufs_per_slab;
-        cache_stats->nr_objs = cache->nr_objs;
-        cache_stats->nr_bufs = cache->nr_bufs;
-        cache_stats->nr_slabs = cache->nr_slabs;
-        cache_stats->nr_free_slabs = cache->nr_free_slabs;
-        strcpy(cache_stats->name, cache->name);
-        /* mutex_unlock(&cache->mutex); */
 
-        mem_usage = (cache_stats->nr_slabs * cache_stats->slab_size) >> 10;
-        mem_reclaimable =
-            (cache_stats->nr_free_slabs * cache_stats->slab_size) >> 10;
+        mem_usage = (cache->nr_slabs * cache->slab_size) >> 10;
+        mem_reclaimable = (cache->nr_free_slabs * cache->slab_size) >> 10;
 
         printk("kmem: %-19s %6zu %3zuk  %4lu %6lu %6lu %7zuk %10zuk\n",
-               cache_stats->name, cache_stats->obj_size,
-               cache_stats->slab_size >> 10, cache_stats->bufs_per_slab,
-               cache_stats->nr_objs, cache_stats->nr_bufs, mem_usage,
-               mem_reclaimable);
+               cache->name, cache->obj_size, cache->slab_size >> 10,
+               cache->bufs_per_slab, cache->nr_objs, cache->nr_bufs,
+               mem_usage, mem_reclaimable);
+
+        /* mutex_unlock(&cache->mutex); */
     }
 
     /* mutex_unlock(&kmem_cache_list_mutex); */
-
-    kmem_free(cache_stats, sizeof(*cache_stats));
 }