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From: John Fastabend <john.fastabend@gmail.com>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>,
	"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 19:45:15 -0800	[thread overview]
Message-ID: <5e15504b79ddb_68832ae93d7145c063@john-XPS-13-9370.notmuch> (raw)
In-Reply-To: <87imlnht6k.fsf@toke.dk>

Toke Høiland-Jørgensen wrote:
> 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
> 

Ah I was just catching up with email and missed itwas already applied.

I can also submit a few fixup patches no problem for the comments and this.

.John

  reply	other threads:[~2020-01-08  3:45 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
2020-01-08  3:45       ` John Fastabend [this message]
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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