From: Johannes Berg <johannes@sipsolutions.net>
To: Taehee Yoo <ap420073@gmail.com>
Cc: "David Miller" <davem@davemloft.net>,
Netdev <netdev@vger.kernel.org>,
linux-wireless@vger.kernel.org,
"Jakub Kicinski" <jakub.kicinski@netronome.com>,
j.vosburgh@gmail.com, vfalico@gmail.com,
"Andy Gospodarek" <andy@greyhouse.net>,
"Jiří Pírko" <jiri@resnulli.us>,
sd@queasysnail.net, "Roopa Prabhu" <roopa@cumulusnetworks.com>,
saeedm@mellanox.com, manishc@marvell.com, rahulv@marvell.com,
kys@microsoft.com, haiyangz@microsoft.com,
"Stephen Hemminger" <stephen@networkplumber.org>,
sashal@kernel.org, hare@suse.de, varun@chelsio.com,
ubraun@linux.ibm.com, kgraul@linux.ibm.com,
"Jay Vosburgh" <jay.vosburgh@canonical.com>,
"Cody Schuffelen" <schuffelen@google.com>,
bjorn@mork.no
Subject: Re: [PATCH net v4 01/12] net: core: limit nested device depth
Date: Tue, 01 Oct 2019 15:57:05 +0200 [thread overview]
Message-ID: <9bbf73e318df17d179014937cb6c1335fb303611.camel@sipsolutions.net> (raw)
In-Reply-To: <CAMArcTW6q=ga1juv_Qp-dKwRwxneAEsX4xQxN-n19oWM-VUQ+w@mail.gmail.com> (sfid-20191001_155348_267769_C0F821E2)
Hi,
(jumping out now, forgive me for being so brief)
> If I understand correctly, you said about the alignment of
> "lower_level" and "upper_level".
> I thought this place is a fine position for variables as regards the
> alignment and I didn't try to put each variable in different places.
>
> If I misunderstood your mention, please let me know.
Not sure what you mean, alignment doesn't matter for them (they're u8).
I was thinking of the packing for the overall struct, we have:
unsigned int max_mtu;
unsigned short type;
unsigned short hard_header_len;
unsigned char min_header_len;
+ unsigned char upper_level, lower_level;
unsigned short needed_headroom;
unsigned short needed_tailroom;
Previously, there was a one byte hole at that spot due to a single
"unsigned char" (after something aligned at least 4 bytes) followed by
"unsigned short" - now you push that out a bit.
If you place the variables a bit lower, below "name_assign_type", you
probably fill a hole instead.
Check out the 'pahole' tool.
johannes
next prev parent reply other threads:[~2019-10-01 13:57 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-28 16:48 [PATCH net v4 00/12] net: fix nested device bugs Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 01/12] net: core: limit nested device depth Taehee Yoo
2019-09-28 19:36 ` Johannes Berg
2019-09-29 11:05 ` Taehee Yoo
2019-10-01 7:11 ` Johannes Berg
2019-10-01 13:53 ` Taehee Yoo
2019-10-01 13:57 ` Johannes Berg [this message]
2019-10-01 18:23 ` Taehee Yoo
2019-10-10 10:19 ` Sabrina Dubroca
2019-10-12 11:42 ` Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 02/12] vlan: use dynamic lockdep key instead of subclass Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 03/12] bonding: fix unexpected IFF_BONDING bit unset Taehee Yoo
2019-09-30 20:48 ` Jay Vosburgh
2019-09-28 16:48 ` [PATCH net v4 04/12] bonding: use dynamic lockdep key instead of subclass Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 05/12] team: use dynamic lockdep key instead of static key Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 06/12] macsec: use dynamic lockdep key instead of subclass Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 07/12] macvlan: " Taehee Yoo
2019-09-28 19:14 ` Johannes Berg
2019-09-29 8:03 ` Taehee Yoo
2019-10-01 7:25 ` Johannes Berg
2019-10-05 9:13 ` Taehee Yoo
2019-10-07 11:41 ` Johannes Berg
2019-10-08 8:13 ` Taehee Yoo
2019-10-21 16:00 ` Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 08/12] macsec: fix refcnt leak in module exit routine Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 09/12] net: core: add ignore flag to netdev_adjacent structure Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 10/12] vxlan: add adjacent link to limit depth level Taehee Yoo
2019-09-28 16:48 ` [PATCH net v4 11/12] net: remove unnecessary variables and callback Taehee Yoo
2019-09-28 19:42 ` Johannes Berg
2019-09-28 16:48 ` [PATCH net v4 12/12] virt_wifi: fix refcnt leak in module exit routine Taehee Yoo
2019-09-28 18:57 ` Johannes Berg
2019-10-07 11:22 ` Sabrina Dubroca
2019-10-08 6:53 ` Taehee Yoo
2019-09-28 19:20 ` [PATCH net v4 00/12] net: fix nested device bugs Johannes Berg
2019-09-29 8:31 ` Taehee Yoo
2019-10-01 7:39 ` Johannes Berg
2019-10-05 9:40 ` Taehee Yoo
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