On 4/5/2019 4:23 PM, Bruce Richardson wrote: > On Fri, Apr 05, 2019 at 11:05:25PM +0800, Ye Xiaolong wrote: >> Hi, Ferruh >> >> On 04/05, Ferruh Yigit wrote: >>> On 4/4/2019 9:51 AM, Xiaolong Ye wrote: >>>> Add a new PMD driver for AF_XDP which is a proposed faster version of >>>> AF_PACKET interface in Linux. More info about AF_XDP, please refer to [1] >>>> [2]. >>>> >>>> This is the vanilla version PMD which just uses a raw buffer registered as >>>> the umem. >>>> >>>> [1] https://fosdem.org/2018/schedule/event/af_xdp/ >>>> [2] https://lwn.net/Articles/745934/ >>>> >>>> Signed-off-by: Xiaolong Ye <xiaolong...@intel.com> >>> >>> <...> >>> >>>> diff --git a/drivers/net/af_xdp/meson.build >>>> b/drivers/net/af_xdp/meson.build >>>> new file mode 100644 >>>> index 000000000..840c93728 >>>> --- /dev/null >>>> +++ b/drivers/net/af_xdp/meson.build >>>> @@ -0,0 +1,19 @@ >>>> +# SPDX-License-Identifier: BSD-3-Clause >>>> +# Copyright(c) 2019 Intel Corporation >>>> + >>>> +if host_machine.system() == 'linux' >>>> + bpf_dep = dependency('libbpf', required: false) >>>> + if bpf_dep.found() >>>> + build = true >>>> + else >>>> + bpf_dep = cc.find_library('bpf', required: false) >>>> + if bpf_dep.found() and cc.has_header('bpf/xsk.h', dependencies: >>>> bpf_dep) and cc.has_header('linux/if_xdp.h') >>>> + build = true >>>> + pkgconfig_extra_libs += '-lbpf' >>>> + else >>>> + build = false >>>> + endif >>>> + endif >>>> + ext_deps += bpf_dep >>>> +endif >>>> +sources = files('rte_eth_af_xdp.c') >>> >>> if system is not 'linux', by default build will be 'true', right, so will >>> it try >>> to build the driver in that case? >>> What about setting "build = false" before the linux check, so won't need to >>> set >>> it false again in the if block, only set it true if dependencies found? >> >> This is a good catch, we do need to initialize build = false first, otherwise >> meson/ninja would just try to build af_xdp pmd if system is not linux, which >> is >> undesired. Do I need to send a separate patch for this so you can squash it >> into >> af_xdp pmd patch? >> >>> And can 'ext_deps' go out of if block? >> >> If we move `ext_deps += bpf_dep` out of if block and build system is not >> linux, there >> would be error "ERROR: Unknown variable "bpf_dep".", so we need either >> initialize >> bpf_dep (to value like NULL?) first or keep `ext_deps += bpf_dep` inside the >> if >> block, I'd prefer keep it as it is, what's you opinion? > > Actually, a suggestion - rather than limiting the build to linux, why not > just limit the build to the presence of libbpf, and not bother checking the > OS?
If this won't cause a problem for other OS in case they have the library, I have no objection.
