06/01/2023 13:41, Morten Brørup: > > From: Bruce Richardson [mailto:bruce.richard...@intel.com] > > Sent: Friday, 6 January 2023 12.48 > > > > On Thu, Jan 05, 2023 at 04:32:40PM -0800, Stephen Hemminger wrote: > > > On Thu, 5 Jan 2023 09:21:18 -0800 > > > Tyler Retzlaff <roret...@linux.microsoft.com> wrote: > > > > > > > On Thu, Jan 05, 2023 at 10:01:31AM +0100, Thomas Monjalon wrote: > > > > > 05/01/2023 08:09, Morten Brørup: > > > > > > > From: Tyler Retzlaff [mailto:roret...@linux.microsoft.com] > > > > > > > +/** > > > > > > > + * @warning > > > > > > > + * @b EXPERIMENTAL: this API may change, or be removed, > > without prior > > > > > > > notice > > > > > > > + * > > > > > > > + * Get the count of leading 0-bits in v. > > > > > > > + * > > > > > > > + * @param v > > > > > > > + * The value. > > > > > > > + * @return > > > > > > > + * The count of leading zero bits. > > > > > > > + */ > > > > > > > +__rte_experimental > > > > > > > +static inline unsigned int > > > > > > > +rte_clzl(unsigned long v) > > > > > > > > > > > > Don't use l (long) and ll (long long) for names (and types), > > use explicit bit lengths, 32 and 64. > > > > > > > > > > > > E.g.: rte_clz32(uint32_t v) > > > > > > > > > > I agree on using numbers. > > > > > > > > > > > > > love the idea, fewer functions too. > > > > > > > > though it is a shame we cannot adopt C11 standard because we could > > just > > > > do away with the bit suffixes entirely. > > > > > > We could but the project needs to support older RHEL releases > > > which have older tool sets. Though probably this is moot point given > > > how much meson seems to change. > > > > True, though meson tends to be a bit easier to update than GCC on a > > system > > - no "pip3 install --upgrade gcc", sadly :-) > > > > If we can't go all the way to C11 support, how about at least going to > > C99 > > support? As far as I know DPDK has never updated its minimum C-standard > > version, and it might be a good idea to start the process of doing so, > > even > > if it is a baby step.
I am in favor of this baby step: define -std=c99 porject-wise and see what are the effects during the year. > The DPDK Getting Started Guide [1] says: > > "Required Tools and Libraries: > [...] > a supported C compiler such as gcc (version 4.9+)" > > GCC version 4.9 supports C11 [2]: > "GCC 4.9 Changes: "ISO C11 support is now at a similar level of completeness > to ISO C99 support [...]" > > So why are we not going to support C11? We should make a plan to switch to C11 during next year. > Probably because of RHEL 7, which only provides GCC 4.8 [3]. > > RHEL 7 was released for GA on June 10, 2014 [4]. If someone has a server with > a nine year old distro still used in production, it is probably because it is > running some legacy application, which is difficult to get up and running on > a newer distro. Partial conclusion: RHEL 7 is probably still widely used in > production. > > However, I have a hard time understanding why anyone would build and/or > deploy a brand new DPDK application (based on DPDK 23.03) on such a server. > Can someone please justify this? > > Are we really going to postpone C11 support in DPDK until June 30, 2026, when > RHEL 7 ends its Extended Life Cycle Support [4]? RHEL does its own choices to support old software for long. Upstream development should move forward. > If so, then the GCC version mentioned in the DPDK Getting Started Guide > should be corrected accordingly. No let's keep GCC 4.9 as a minimum for now. If needed we could upgrade it later.
