Re: [PATCH bpf] nfp: bpf: fix latency bug when updating stack index register

2019-08-26 Thread Daniel Borkmann
On 8/24/19 4:00 AM, Jakub Kicinski wrote: From: Jiong Wang NFP is using Local Memory to model stack. LM_addr could be used as base of a 16 32-bit word region of Local Memory. Then, if the stack offset is beyond the current region, the local index needs to be updated. The update needs at least t

Re: [PATCH bpf] nfp: bpf: fix latency bug when updating stack index register

2019-08-26 Thread Jakub Kicinski
On Mon, 26 Aug 2019 18:25:10 +0200, Daniel Borkmann wrote: > On 8/26/19 6:18 PM, Alexei Starovoitov wrote: > > On Mon, Aug 26, 2019 at 8:57 AM Jakub Kicinski > > wrote: > >> On Sun, Aug 25, 2019 at 10:37 PM Song Liu wrote: > >>> On Fri, Aug 23, 2019 at 7:04 PM Jakub Kicinski wrote: > F

Re: [PATCH bpf] nfp: bpf: fix latency bug when updating stack index register

2019-08-26 Thread Daniel Borkmann
On 8/26/19 6:18 PM, Alexei Starovoitov wrote: On Mon, Aug 26, 2019 at 8:57 AM Jakub Kicinski wrote: On Sun, Aug 25, 2019 at 10:37 PM Song Liu wrote: On Fri, Aug 23, 2019 at 7:04 PM Jakub Kicinski wrote: From: Jiong Wang NFP is using Local Memory to model stack. LM_addr could be used as bas

Re: [PATCH bpf] nfp: bpf: fix latency bug when updating stack index register

2019-08-26 Thread Alexei Starovoitov
On Mon, Aug 26, 2019 at 8:57 AM Jakub Kicinski wrote: > > On Sun, Aug 25, 2019 at 10:37 PM Song Liu wrote: > > On Fri, Aug 23, 2019 at 7:04 PM Jakub Kicinski wrote: > > > From: Jiong Wang > > > > > > NFP is using Local Memory to model stack. LM_addr could be used as base of > > > a 16 32-bit wor

Re: [PATCH bpf] nfp: bpf: fix latency bug when updating stack index register

2019-08-26 Thread Jakub Kicinski
On Sun, Aug 25, 2019 at 10:37 PM Song Liu wrote: > On Fri, Aug 23, 2019 at 7:04 PM Jakub Kicinski wrote: > > From: Jiong Wang > > > > NFP is using Local Memory to model stack. LM_addr could be used as base of > > a 16 32-bit word region of Local Memory. Then, if the stack offset is > > beyond the

Re: [PATCH bpf] nfp: bpf: fix latency bug when updating stack index register

2019-08-25 Thread Song Liu
On Fri, Aug 23, 2019 at 7:04 PM Jakub Kicinski wrote: > > From: Jiong Wang > > NFP is using Local Memory to model stack. LM_addr could be used as base of > a 16 32-bit word region of Local Memory. Then, if the stack offset is > beyond the current region, the local index needs to be updated. The u

[PATCH bpf] nfp: bpf: fix latency bug when updating stack index register

2019-08-23 Thread Jakub Kicinski
From: Jiong Wang NFP is using Local Memory to model stack. LM_addr could be used as base of a 16 32-bit word region of Local Memory. Then, if the stack offset is beyond the current region, the local index needs to be updated. The update needs at least three cycles to take effect, therefore the se