From: Stephen Hemminger <stephen@networkplumber.org>
To: Tyler Retzlaff <roretzla@linux.microsoft.com>
Cc: dev@dpdk.org
Subject: Re: RFC acceptable handling of VLAs across toolchains
Date: Tue, 7 Nov 2023 18:31:14 -0800 [thread overview]
Message-ID: <20231107183114.330c2d8e@hermes.local> (raw)
In-Reply-To: <20231107193220.GA15232@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net>
On Tue, 7 Nov 2023 11:32:20 -0800
Tyler Retzlaff <roretzla@linux.microsoft.com> wrote:
> hi folks,
>
> i'm seeking advice. we have use of VLAs which are now optional in
> standard C. some toolchains provide a conformant implementation and msvc
> does not (and never will).
>
> we seem to have a few options, just curious about what people would
> prefer.
>
> * use alloca
>
> * use dynamically allocated storage
>
> * conditional compiled code where the msvc leg uses one of the previous
> two options
>
> i'll leave it simple for now, i'd like to hear input rather than provide
> a recommendation for now.
>
VLAs are a bug magnet. Best to avoid them, most code doesn't need them.
The one common use case is code that accepts a burst of packets.
But such code could easily have an upper bound if necessary.
Please don't add more to the maze of #ifdef's
next prev parent reply other threads:[~2023-11-08 2:31 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-07 19:32 Tyler Retzlaff
2023-11-08 2:31 ` Stephen Hemminger [this message]
2023-11-08 3:25 ` Tyler Retzlaff
2023-11-08 8:19 ` Morten Brørup
2023-11-08 16:51 ` Stephen Hemminger
2023-11-08 17:48 ` Morten Brørup
2023-11-09 10:25 ` RFC: default burst sizes in rte_config Morten Brørup
2023-11-09 20:26 ` RFC acceptable handling of VLAs across toolchains Tyler Retzlaff
2024-03-21 0:12 ` Tyler Retzlaff
2024-04-04 17:15 ` [PATCH 0/4] RFC samples converting VLA to alloca Tyler Retzlaff
2024-04-04 17:15 ` [PATCH 1/4] latencystats: use alloca instead of vla trivial Tyler Retzlaff
2024-04-06 15:28 ` Morten Brørup
2024-04-07 9:36 ` Mattias Rönnblom
2024-04-07 17:00 ` Stephen Hemminger
2024-04-04 17:15 ` [PATCH 2/4] hash: " Tyler Retzlaff
2024-04-06 16:01 ` Morten Brørup
2024-04-04 17:15 ` [PATCH 3/4] vhost: use alloca instead of vla sizeof Tyler Retzlaff
2024-04-06 22:30 ` Morten Brørup
2024-04-04 17:15 ` [PATCH 4/4] dispatcher: use alloca instead of vla multi dimensional Tyler Retzlaff
2024-04-06 15:49 ` Morten Brørup
2024-04-07 9:31 ` [PATCH 0/4] RFC samples converting VLA to alloca Mattias Rönnblom
2024-04-07 11:07 ` Morten Brørup
2024-04-07 17:03 ` Stephen Hemminger
2024-04-08 15:27 ` Tyler Retzlaff
2024-04-08 15:53 ` Morten Brørup
2024-04-09 8:28 ` Konstantin Ananyev
2024-04-09 15:08 ` Tyler Retzlaff
2024-04-10 9:58 ` Konstantin Ananyev
2024-04-10 17:03 ` Tyler Retzlaff
2024-04-10 7:32 ` Mattias Rönnblom
2024-04-10 7:52 ` Morten Brørup
2024-04-10 17:04 ` Tyler Retzlaff
2024-04-10 7:27 ` Mattias Rönnblom
2024-04-10 17:10 ` Tyler Retzlaff
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