From: Alexander Duyck <alexander.duyck@gmail.com>
To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: sridhar.samudrala@intel.com, edumazet@google.com,
davem@davemloft.net, linux-api@vger.kernel.org
Subject: [net-next PATCH v3 1/8] net: Busy polling should ignore sender CPUs
Date: Fri, 24 Mar 2017 10:07:53 -0700 [thread overview]
Message-ID: <20170324170753.15226.91099.stgit@localhost.localdomain> (raw)
In-Reply-To: <20170324164902.15226.48358.stgit@localhost.localdomain>
From: Alexander Duyck <alexander.h.duyck@intel.com>
This patch is a cleanup/fix for NAPI IDs following the changes that made it
so that sender_cpu and napi_id were doing a better job of sharing the same
location in the sk_buff.
One issue I found is that we weren't validating the napi_id as being valid
before we started trying to setup the busy polling. This change corrects
that by using the MIN_NAPI_ID value that is now used in both allocating the
NAPI IDs, as well as validating them.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
---
include/net/busy_poll.h | 9 +++++++--
net/core/dev.c | 13 +++++++++----
2 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index c0452de83086..3fcda9e70c3f 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -35,6 +35,12 @@
extern unsigned int sysctl_net_busy_read __read_mostly;
extern unsigned int sysctl_net_busy_poll __read_mostly;
+/* 0 - Reserved to indicate value not set
+ * 1..NR_CPUS - Reserved for sender_cpu
+ * NR_CPUS+1..~0 - Region available for NAPI IDs
+ */
+#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1))
+
static inline bool net_busy_loop_on(void)
{
return sysctl_net_busy_poll;
@@ -58,10 +64,9 @@ static inline unsigned long busy_loop_end_time(void)
static inline bool sk_can_busy_loop(const struct sock *sk)
{
- return sk->sk_ll_usec && sk->sk_napi_id && !signal_pending(current);
+ return sk->sk_ll_usec && !signal_pending(current);
}
-
static inline bool busy_loop_timeout(unsigned long end_time)
{
unsigned long now = busy_loop_us_clock();
diff --git a/net/core/dev.c b/net/core/dev.c
index 7869ae3837ca..ab337bf5bbf4 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5066,15 +5066,20 @@ bool sk_busy_loop(struct sock *sk, int nonblock)
int (*napi_poll)(struct napi_struct *napi, int budget);
void *have_poll_lock = NULL;
struct napi_struct *napi;
+ unsigned int napi_id;
int rc;
restart:
+ napi_id = READ_ONCE(sk->sk_napi_id);
+ if (napi_id < MIN_NAPI_ID)
+ return 0;
+
rc = false;
napi_poll = NULL;
rcu_read_lock();
- napi = napi_by_id(sk->sk_napi_id);
+ napi = napi_by_id(napi_id);
if (!napi)
goto out;
@@ -5143,10 +5148,10 @@ static void napi_hash_add(struct napi_struct *napi)
spin_lock(&napi_hash_lock);
- /* 0..NR_CPUS+1 range is reserved for sender_cpu use */
+ /* 0..NR_CPUS range is reserved for sender_cpu use */
do {
- if (unlikely(++napi_gen_id < NR_CPUS + 1))
- napi_gen_id = NR_CPUS + 1;
+ if (unlikely(++napi_gen_id < MIN_NAPI_ID))
+ napi_gen_id = MIN_NAPI_ID;
} while (napi_by_id(napi_gen_id));
napi->napi_id = napi_gen_id;
next prev parent reply other threads:[~2017-03-24 17:08 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-24 17:07 [net-next PATCH v3 0/8] Add busy poll support for epoll Alexander Duyck
2017-03-24 17:07 ` Alexander Duyck [this message]
2017-03-24 17:08 ` [net-next PATCH v3 2/8] tcp: Record Rx hash and NAPI ID in tcp_child_process Alexander Duyck
2017-03-24 17:08 ` [net-next PATCH v3 3/8] net: Only define skb_mark_napi_id in one spot instead of two Alexander Duyck
2017-03-24 17:08 ` [net-next PATCH v3 4/8] net: Change return type of sk_busy_loop from bool to void Alexander Duyck
2019-03-20 18:35 ` Christoph Paasch
2019-03-20 19:40 ` David Miller
2019-03-21 9:45 ` Paolo Abeni
2019-03-21 14:28 ` Willem de Bruijn
2019-03-21 16:43 ` Alexander Duyck
2019-03-22 3:05 ` Christoph Paasch
2019-03-22 10:33 ` Paolo Abeni
2019-03-22 12:59 ` Eric Dumazet
2019-03-22 13:35 ` Paolo Abeni
2019-03-22 19:25 ` Christoph Paasch
2017-03-24 17:08 ` [net-next PATCH v3 5/8] net: Track start of busy loop instead of when it should end Alexander Duyck
2017-03-25 3:34 ` Eric Dumazet
2017-03-24 17:08 ` [net-next PATCH v3 6/8] net: Commonize busy polling code to focus on napi_id instead of socket Alexander Duyck
2017-03-24 17:08 ` [net-next PATCH v3 7/8] epoll: Add busy poll support to epoll with socket fds Alexander Duyck
2017-03-25 3:33 ` Eric Dumazet
2017-03-24 17:08 ` [net-next PATCH v3 8/8] net: Introduce SO_INCOMING_NAPI_ID Alexander Duyck
2017-03-25 2:23 ` [net-next PATCH v3 0/8] Add busy poll support for epoll David Miller
2017-03-25 3:49 ` David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170324170753.15226.91099.stgit@localhost.localdomain \
--to=alexander.duyck@gmail.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=sridhar.samudrala@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).