The 11/10/2017 10:06, Jia He wrote: > > > On 11/9/2017 5:38 PM, Ananyev, Konstantin Wrote: > > > >>-----Original Message----- > >>From: Jianbo Liu [mailto:jianbo....@arm.com] > >>Sent: Thursday, November 9, 2017 4:56 AM > >>To: Jia He <hejia...@gmail.com> > >>Cc: Richardson, Bruce <bruce.richard...@intel.com>; > >>jerin.ja...@caviumnetworks.com; dev@dpdk.org; olivier.m...@6wind.com; > >>Ananyev, Konstantin <konstantin.anan...@intel.com>; hemant.agra...@nxp.com; > >>jia...@hxt-semitech.com > >>Subject: Re: [PATCH 1/3] eal/arm64: remove the braces {} for dmb(),dsb() > >> > >>The 11/09/2017 12:43, Jia He wrote: > >>>Hi Jianbo > >>> > >>> > >>>On 11/9/2017 11:21 AM, Jianbo Liu Wrote: > >>>>The 11/09/2017 11:14, Jia He wrote: > >>>>>On 11/9/2017 9:22 AM, Jia He Wrote: > >>>>>>Hi Bruce > >>>>>> > >>>>>> > >>>>>>On 11/8/2017 6:28 PM, Bruce Richardson Wrote: > >>>>>>>On Wed, Nov 08, 2017 at 06:17:10AM +0000, Jia He wrote: > >>>>>>>>for the code as follows: > >>>>>>>>if (condition) > >>>>>>>> rte_smp_rmb(); > >>>>>>>>else > >>>>>>>> rte_smp_wmb(); > >>>>>>>>Without this patch, compiler will report this error: > >>>>>>>>error: 'else' without a previous 'if' > >>>>>>>> > >>>>>>>>Signed-off-by: Jia He <hejia...@gmail.com> > >>>>>>>>Signed-off-by: jia...@hxt-semitech.com > >>>>>>>>--- > >>>>>>>> lib/librte_eal/common/include/arch/arm/rte_atomic_64.h | 4 ++-- > >>>>>>>> 1 file changed, 2 insertions(+), 2 deletions(-) > >>>>>>>> > >>>>>>>>diff --git > >>>>>>>>a/lib/librte_eal/common/include/arch/arm/rte_atomic_64.h > >>>>>>>>b/lib/librte_eal/common/include/arch/arm/rte_atomic_64.h > >>>>>>>>index 0b70d62..38c3393 100644 > >>>>>>>>--- a/lib/librte_eal/common/include/arch/arm/rte_atomic_64.h > >>>>>>>>+++ b/lib/librte_eal/common/include/arch/arm/rte_atomic_64.h > >>>>>>>>@@ -43,8 +43,8 @@ extern "C" { > >>>>>>>> #include "generic/rte_atomic.h" > >>>>>>>> -#define dsb(opt) { asm volatile("dsb " #opt : : : "memory"); } > >>>>>>>>-#define dmb(opt) { asm volatile("dmb " #opt : : : "memory"); } > >>>>>>>>+#define dsb(opt) asm volatile("dsb " #opt : : : "memory"); > >>>>>>>>+#define dmb(opt) asm volatile("dmb " #opt : : : "memory"); > >>>>>>>Need to remove the trailing ";" I too I think. > >>>>>>>Alternatively, to keep the braces, the standard practice is to use > >>>>>>>do { ... } while(0) > >>>>>>If trailing ";" is not removed > >>>>>>the code: > >>>>>>if (condition) > >>>>>> rte_smp_rmb(); > >>>>>>else > >>>>>> anything(); > >>>>>> > >>>>Sorry, why not use two different functions as your conditions passed in > >>>>are fixed in the calling functions. > >>>Do you mean to split update_tail() into update_tail_enqueue() and > >>>update_tail_dequeue()? > >>Yes. So it's not need to change dsb/dmb. > >That's a good idea - but you still might hit the same problem in > >Some different place in future... > >Why not to convert these macros into 'always_inline' functions then? > >Konstantin > > > It makes things more complex > opt needs to be redefined with types > such as : __attribute__((always_inline)) void dsb( char* opt) > and the input paramenter shoud be > #define sy "sy" > #define ld "ld" > > And the "#" in asm codes needs to be considerred more. > > IMO, the kernel way is simple and clean, isn't it? > #define dmb(opt) asm volatile("dmb " #opt : : : "memory") > Another choice is adding the do/while. > > @Ananyev @Jianbo > Any thoughts? >
I think it's a good to keep your v4. Jianbo IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
