Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
Merge branch 'net-adjust-conservative-values-around-napi'
Jason Xing says:
====================
net: adjust conservative values around napi
This series keeps at least 96 skbs per cpu and frees 32 skbs at one
time in conclusion. More initial discussions with Eric can be seen at
the link [1].
[1]: https://lore.kernel.org/all/CAL+tcoBEEjO=-yvE7ZJ4sB2smVBzUht1gJN85CenJhOKV====================
Link: https://patch.msgid.link/20251118070646.61344-1-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+12
-8
+12
-8
net/core/skbuff.c
+12
-8
net/core/skbuff.c
···
223
223
skb_panic(skb, sz, addr, __func__);
224
224
}
225
225
226
-
#define NAPI_SKB_CACHE_SIZE 64
227
-
#define NAPI_SKB_CACHE_BULK 16
228
-
#define NAPI_SKB_CACHE_HALF (NAPI_SKB_CACHE_SIZE / 2)
226
+
#define NAPI_SKB_CACHE_SIZE 128
227
+
#define NAPI_SKB_CACHE_BULK 32
228
+
#define NAPI_SKB_CACHE_FREE 32
229
229
230
230
struct napi_alloc_cache {
231
231
local_lock_t bh_lock;
···
299
299
}
300
300
301
301
skb = nc->skb_cache[--nc->skb_count];
302
+
if (nc->skb_count)
303
+
prefetch(nc->skb_cache[nc->skb_count - 1]);
302
304
local_unlock_nested_bh(&napi_alloc_cache.bh_lock);
303
305
kasan_mempool_unpoison_object(skb, skbuff_cache_size);
304
306
···
1447
1445
static void napi_skb_cache_put(struct sk_buff *skb)
1448
1446
{
1449
1447
struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache);
1450
-
u32 i;
1451
1448
1452
1449
if (!kasan_mempool_poison_object(skb))
1453
1450
return;
···
1455
1454
nc->skb_cache[nc->skb_count++] = skb;
1456
1455
1457
1456
if (unlikely(nc->skb_count == NAPI_SKB_CACHE_SIZE)) {
1458
-
for (i = NAPI_SKB_CACHE_HALF; i < NAPI_SKB_CACHE_SIZE; i++)
1457
+
u32 i, remaining = NAPI_SKB_CACHE_SIZE - NAPI_SKB_CACHE_FREE;
1458
+
1459
+
for (i = remaining; i < NAPI_SKB_CACHE_SIZE; i++)
1459
1460
kasan_mempool_unpoison_object(nc->skb_cache[i],
1460
1461
skbuff_cache_size);
1461
1462
1462
-
kmem_cache_free_bulk(net_hotdata.skbuff_cache, NAPI_SKB_CACHE_HALF,
1463
-
nc->skb_cache + NAPI_SKB_CACHE_HALF);
1464
-
nc->skb_count = NAPI_SKB_CACHE_HALF;
1463
+
kmem_cache_free_bulk(net_hotdata.skbuff_cache,
1464
+
NAPI_SKB_CACHE_FREE,
1465
+
nc->skb_cache + remaining);
1466
+
nc->skb_count = remaining;
1465
1467
}
1466
1468
local_unlock_nested_bh(&napi_alloc_cache.bh_lock);
1467
1469
}