Slab: slots statistics.

For each slot, the number of total and used entries, as well as
the number of allocation requests and failures, are tracked.
This commit is contained in:
Ruslan Ermilov 2016-12-07 22:25:37 +03:00
parent 366f131c38
commit 9ccf719be6
2 changed files with 57 additions and 11 deletions

View File

@ -120,7 +120,13 @@ ngx_slab_init(ngx_slab_pool_t *pool)
}
p += n * sizeof(ngx_slab_page_t);
size -= n * sizeof(ngx_slab_page_t);
pool->stats = (ngx_slab_stat_t *) p;
ngx_memzero(pool->stats, n * sizeof(ngx_slab_stat_t));
p += n * sizeof(ngx_slab_stat_t);
size -= n * (sizeof(ngx_slab_page_t) + sizeof(ngx_slab_stat_t));
pages = (ngx_uint_t) (size / (ngx_pagesize + sizeof(ngx_slab_page_t)));
@ -205,6 +211,8 @@ ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
slot = 0;
}
pool->stats[slot].reqs++;
ngx_log_debug2(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0,
"slab alloc: %uz slot: %ui", size, slot);
@ -232,11 +240,13 @@ ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
i = (n * sizeof(uintptr_t) * 8 + i) << shift;
p = (uintptr_t) bitmap + i;
pool->stats[slot].used++;
if (bitmap[n] == NGX_SLAB_BUSY) {
for (n = n + 1; n < map; n++) {
if (bitmap[n] != NGX_SLAB_BUSY) {
p = (uintptr_t) bitmap + i;
goto done;
}
}
@ -249,8 +259,6 @@ ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
page->prev = NGX_SLAB_SMALL;
}
p = (uintptr_t) bitmap + i;
goto done;
}
}
@ -276,6 +284,8 @@ ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
p = ngx_slab_page_addr(pool, page) + (i << shift);
pool->stats[slot].used++;
goto done;
}
@ -305,6 +315,8 @@ ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
p = ngx_slab_page_addr(pool, page) + (i << shift);
pool->stats[slot].used++;
goto done;
}
}
@ -339,8 +351,12 @@ ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
slots[slot].next = page;
pool->stats[slot].total += (ngx_pagesize >> shift) - n;
p = ngx_slab_page_addr(pool, page) + (n << shift);
pool->stats[slot].used++;
goto done;
} else if (shift == ngx_slab_exact_shift) {
@ -351,8 +367,12 @@ ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
slots[slot].next = page;
pool->stats[slot].total += sizeof(uintptr_t) * 8;
p = ngx_slab_page_addr(pool, page);
pool->stats[slot].used++;
goto done;
} else { /* shift > ngx_slab_exact_shift */
@ -363,14 +383,20 @@ ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
slots[slot].next = page;
pool->stats[slot].total += ngx_pagesize >> shift;
p = ngx_slab_page_addr(pool, page);
pool->stats[slot].used++;
goto done;
}
}
p = 0;
pool->stats[slot].fails++;
done:
ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0,
@ -425,7 +451,7 @@ ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
{
size_t size;
uintptr_t slab, m, *bitmap;
ngx_uint_t n, type, slot, shift, map;
ngx_uint_t i, n, type, slot, shift, map;
ngx_slab_page_t *slots, *page;
ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0, "slab free: %p", p);
@ -458,10 +484,10 @@ ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
((uintptr_t) p & ~((uintptr_t) ngx_pagesize - 1));
if (bitmap[n] & m) {
slot = shift - pool->min_shift;
if (page->next == NULL) {
slots = ngx_slab_slots(pool);
slot = shift - pool->min_shift;
page->next = slots[slot].next;
slots[slot].next = page;
@ -484,14 +510,16 @@ ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
map = (ngx_pagesize >> shift) / (sizeof(uintptr_t) * 8);
for (n = 1; n < map; n++) {
if (bitmap[n]) {
for (i = 1; i < map; i++) {
if (bitmap[i]) {
goto done;
}
}
ngx_slab_free_pages(pool, page, 1);
pool->stats[slot].total -= (ngx_pagesize >> shift) - n;
goto done;
}
@ -508,9 +536,10 @@ ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
}
if (slab & m) {
slot = ngx_slab_exact_shift - pool->min_shift;
if (slab == NGX_SLAB_BUSY) {
slots = ngx_slab_slots(pool);
slot = ngx_slab_exact_shift - pool->min_shift;
page->next = slots[slot].next;
slots[slot].next = page;
@ -527,6 +556,8 @@ ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
ngx_slab_free_pages(pool, page, 1);
pool->stats[slot].total -= sizeof(uintptr_t) * 8;
goto done;
}
@ -545,10 +576,10 @@ ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
+ NGX_SLAB_MAP_SHIFT);
if (slab & m) {
slot = shift - pool->min_shift;
if (page->next == NULL) {
slots = ngx_slab_slots(pool);
slot = shift - pool->min_shift;
page->next = slots[slot].next;
slots[slot].next = page;
@ -565,6 +596,8 @@ ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
ngx_slab_free_pages(pool, page, 1);
pool->stats[slot].total -= ngx_pagesize >> shift;
goto done;
}
@ -604,6 +637,8 @@ ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
done:
pool->stats[slot].used--;
ngx_slab_junk(p, size);
return;

View File

@ -22,6 +22,15 @@ struct ngx_slab_page_s {
};
typedef struct {
ngx_uint_t total;
ngx_uint_t used;
ngx_uint_t reqs;
ngx_uint_t fails;
} ngx_slab_stat_t;
typedef struct {
ngx_shmtx_sh_t lock;
@ -32,6 +41,8 @@ typedef struct {
ngx_slab_page_t *last;
ngx_slab_page_t free;
ngx_slab_stat_t *stats;
u_char *start;
u_char *end;