From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Fri, 6 Sep 2019 22:30:00 -0700
Subject: net/tls: align non temporal copy to cache lines
Patch-mainline: v5.4-rc1
Git-commit: e681cc603a79b5907a7388e1d4587779b0fe8ff2
References: bsc#1154353
Unlike normal TCP code TLS has to touch the cache lines
it copies into to fill header info. On memory-heavy workloads
having non temporal stores and normal accesses targeting
the same cache line leads to significant overhead.
Measured 3% overhead running 3600 round robin connections
with additional memory heavy workload.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/tls/tls_device.c | 33 ++++++++++++++++++++++++++++-----
1 file changed, 28 insertions(+), 5 deletions(-)
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -372,6 +372,31 @@ static int tls_do_allocation(struct sock
return 0;
}
+static int tls_device_copy_data(void *addr, size_t bytes, struct iov_iter *i)
+{
+ size_t pre_copy, nocache;
+
+ pre_copy = ~((unsigned long)addr - 1) & (SMP_CACHE_BYTES - 1);
+ if (pre_copy) {
+ pre_copy = min(pre_copy, bytes);
+ if (copy_from_iter(addr, pre_copy, i) != pre_copy)
+ return -EFAULT;
+ bytes -= pre_copy;
+ addr += pre_copy;
+ }
+
+ nocache = round_down(bytes, SMP_CACHE_BYTES);
+ if (copy_from_iter_nocache(addr, nocache, i) != nocache)
+ return -EFAULT;
+ bytes -= nocache;
+ addr += nocache;
+
+ if (bytes && copy_from_iter(addr, bytes, i) != bytes)
+ return -EFAULT;
+
+ return 0;
+}
+
static int tls_push_data(struct sock *sk,
struct iov_iter *msg_iter,
size_t size, int flags,
@@ -445,12 +470,10 @@ handle_error:
copy = min_t(size_t, size, (pfrag->size - pfrag->offset));
copy = min_t(size_t, copy, (max_open_record_len - record->len));
- if (copy_from_iter_nocache(page_address(pfrag->page) +
- pfrag->offset,
- copy, msg_iter) != copy) {
- rc = -EFAULT;
+ rc = tls_device_copy_data(page_address(pfrag->page) +
+ pfrag->offset, copy, msg_iter);
+ if (rc)
goto handle_error;
- }
tls_append_frag(record, pfrag, copy);
size -= copy;