From: Jakub Kicinski <kuba@kernel.org>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com,
Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH net-next 3/5] net: skbuff: move alloc_cpu into a potential hole
Date: Fri, 14 Apr 2023 09:01:03 -0700 [thread overview]
Message-ID: <20230414160105.172125-4-kuba@kernel.org> (raw)
In-Reply-To: <20230414160105.172125-1-kuba@kernel.org>
alloc_cpu is currently between 4 byte fields, so it's almost
guaranteed to create a 2B hole. It has a knock on effect of
creating a 4B hole after @end (and @end and @tail being in
different cachelines).
None of this matters hugely, but for kernel configs which
don't enable all the features there may well be a 2B hole
after the bitfield. Move alloc_cpu there.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
include/linux/skbuff.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 45c3044e8123..fd6344aca94a 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -991,6 +991,8 @@ struct sk_buff {
__u16 tc_index; /* traffic control index */
#endif
+ u16 alloc_cpu;
+
union {
__wsum csum;
struct {
@@ -1014,7 +1016,6 @@ struct sk_buff {
unsigned int sender_cpu;
};
#endif
- u16 alloc_cpu;
#ifdef CONFIG_NETWORK_SECMARK
__u32 secmark;
#endif
--
2.39.2
next prev parent reply other threads:[~2023-04-14 16:04 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-14 16:01 [PATCH net-next 0/5] net: skbuff: hide some bitfield members Jakub Kicinski
2023-04-14 16:01 ` [PATCH net-next 1/5] net: skbuff: hide wifi_acked when CONFIG_WIRELESS not set Jakub Kicinski
2023-04-14 17:46 ` Florian Fainelli
2023-04-14 16:01 ` [PATCH net-next 2/5] net: skbuff: hide csum_not_inet when CONFIG_IP_SCTP " Jakub Kicinski
2023-04-14 17:47 ` Florian Fainelli
2023-04-14 16:01 ` Jakub Kicinski [this message]
2023-04-14 17:51 ` [PATCH net-next 3/5] net: skbuff: move alloc_cpu into a potential hole Florian Fainelli
2023-04-14 16:01 ` [PATCH net-next 4/5] net: skbuff: push nf_trace down the bitfield Jakub Kicinski
2023-04-14 17:50 ` Florian Fainelli
2023-04-14 21:06 ` Florian Westphal
2023-04-15 8:31 ` Pablo Neira Ayuso
2023-04-17 4:12 ` Jakub Kicinski
2023-04-14 16:01 ` [PATCH net-next 5/5] net: skbuff: hide nf_trace and ipvs_property Jakub Kicinski
2023-04-14 17:50 ` Florian Fainelli
2023-04-14 21:09 ` Florian Westphal
2023-04-14 22:07 ` Jakub Kicinski
2023-04-14 23:11 ` Florian Westphal
2023-04-15 0:44 ` Jakub Kicinski
2023-04-15 0:32 ` kernel test robot
2023-04-15 0:43 ` kernel test robot
2023-04-17 12:09 ` Simon Horman
2023-04-15 11:53 ` [PATCH net-next 0/5] net: skbuff: hide some bitfield members Eric Dumazet
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