From: "Toke Høiland-Jørgensen" <toke@redhat•com>
To: "John Fastabend" <john.fastabend@gmail•com>,
"Björn Töpel" <bjorn.topel@gmail•com>,
netdev@vger•kernel.org, ast@kernel•org, daniel@iogearbox•net
Cc: "Björn Töpel" <bjorn.topel@intel•com>,
bpf@vger•kernel.org, davem@davemloft•net,
jakub.kicinski@netronome•com, hawk@kernel•org,
john.fastabend@gmail•com, magnus.karlsson@intel•com,
jonathan.lemon@gmail•com
Subject: RE: [PATCH bpf-next v2 7/8] xdp: remove map_to_flush and map swap detection
Date: Tue, 07 Jan 2020 22:07:15 +0100 [thread overview]
Message-ID: <87imlnht6k.fsf@toke.dk> (raw)
In-Reply-To: <5e14caaaab6f7_67962afd051fc5c06f@john-XPS-13-9370.notmuch>
John Fastabend <john.fastabend@gmail•com> writes:
> Björn Töpel wrote:
>> From: Björn Töpel <bjorn.topel@intel•com>
>>
>> Now that all XDP maps that can be used with bpf_redirect_map() tracks
>> entries to be flushed in a global fashion, there is not need to track
>> that the map has changed and flush from xdp_do_generic_map()
>> anymore. All entries will be flushed in xdp_do_flush_map().
>>
>> This means that the map_to_flush can be removed, and the corresponding
>> checks. Moving the flush logic to one place, xdp_do_flush_map(), give
>> a bulking behavior and performance boost.
>>
>> Acked-by: Toke Høiland-Jørgensen <toke@redhat•com>
>> Signed-off-by: Björn Töpel <bjorn.topel@intel•com>
>> ---
>
> __dev_map_flush() still has rcu_read_lock/unlock() around flush_list by
> this point, assuming I've followed along correctly. Can we drop those
> now seeing its per CPU and all list ops are per-cpu inside napi context?
Hmm, I guess so? :)
> Two reasons to consider, with this patch dev_map_flush() is always
> called even if the list is empty so even in TX case without redirect.
> But probably more important it makes the locking requirements more clear.
> Could probably be done in a follow up patch but wanted to bring it up.
This series was already merged, but I'll follow up with the non-map
redirect change. This requires a bit of refactoring anyway, so I can
incorporate the lock removal into that...
-Toke
next prev parent reply other threads:[~2020-01-07 21:07 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-19 6:09 [PATCH bpf-next v2 0/8] Simplify xdp_do_redirect_map()/xdp_do_flush_map() and XDP maps Björn Töpel
2019-12-19 6:09 ` [PATCH bpf-next v2 1/8] xdp: simplify devmap cleanup Björn Töpel
2020-01-07 17:32 ` John Fastabend
2020-01-08 10:08 ` Björn Töpel
2019-12-19 6:10 ` [PATCH bpf-next v2 2/8] xdp: simplify cpumap cleanup Björn Töpel
2019-12-19 6:10 ` [PATCH bpf-next v2 3/8] xdp: fix graze->grace type-o in cpumap comments Björn Töpel
2020-01-07 17:33 ` John Fastabend
2019-12-19 6:10 ` [PATCH bpf-next v2 4/8] xsk: make xskmap flush_list common for all map instances Björn Töpel
2020-01-07 17:54 ` John Fastabend
2020-01-08 10:13 ` Björn Töpel
2020-01-08 15:52 ` John Fastabend
2020-01-08 16:01 ` Toke Høiland-Jørgensen
2019-12-19 6:10 ` [PATCH bpf-next v2 5/8] xdp: make devmap " Björn Töpel
2020-01-07 17:58 ` John Fastabend
2020-01-08 10:16 ` Björn Töpel
2020-01-08 10:23 ` Toke Høiland-Jørgensen
2020-01-08 10:25 ` Björn Töpel
2019-12-19 6:10 ` [PATCH bpf-next v2 6/8] xdp: make cpumap " Björn Töpel
2020-01-07 17:59 ` John Fastabend
2019-12-19 6:10 ` [PATCH bpf-next v2 7/8] xdp: remove map_to_flush and map swap detection Björn Töpel
2020-01-07 18:15 ` John Fastabend
2020-01-07 21:07 ` Toke Høiland-Jørgensen [this message]
2020-01-08 3:45 ` John Fastabend
2020-01-08 10:24 ` Björn Töpel
2019-12-19 6:10 ` [PATCH bpf-next v2 8/8] xdp: simplify __bpf_tx_xdp_map() Björn Töpel
2019-12-19 7:18 ` [PATCH bpf-next v2 0/8] Simplify xdp_do_redirect_map()/xdp_do_flush_map() and XDP maps Jesper Dangaard Brouer
2019-12-20 5:21 ` Alexei Starovoitov
2019-12-20 7:46 ` Jesper Dangaard Brouer
2019-12-20 9:26 ` Jesper Dangaard Brouer
2019-12-20 10:29 ` Toke Høiland-Jørgensen
2020-01-07 11:10 ` Björn Töpel
2020-01-07 11:25 ` Toke Høiland-Jørgensen
2020-01-07 13:05 ` Jesper Dangaard Brouer
2020-01-07 13:27 ` Toke Høiland-Jørgensen
2020-01-07 13:52 ` Jesper Dangaard Brouer
2020-01-07 14:18 ` Toke Høiland-Jørgensen
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