Re: [PATCH] arm64: insn: Simulate nop and push instruction for better uprobe performance

在 2024/8/30 3:26, Andrii Nakryiko 写道: > On Tue, Aug 27, 2024 at 4:34 AM Liao, Chang wrote: >> >> Hi, Mark >> >> Would you like to discuss this patch further, or do you still believe >> emulating >> STP to push FP/LR into the stack in kernel is not a good idea? >> > > Please send an updated ve

Re: [PATCH] arm64: insn: Simulate nop and push instruction for better uprobe performance

On Tue, Aug 27, 2024 at 4:34 AM Liao, Chang wrote: > > Hi, Mark > > Would you like to discuss this patch further, or do you still believe > emulating > STP to push FP/LR into the stack in kernel is not a good idea? > Please send an updated version of your patches taking into account various smal

Re: [PATCH] arm64: insn: Simulate nop and push instruction for better uprobe performance

Hi, Mark Would you like to discuss this patch further, or do you still believe emulating STP to push FP/LR into the stack in kernel is not a good idea? Thanks. 在 2024/8/21 15:55, Liao, Chang 写道: > Hi, Mark > > My bad for taking so long to rely, I generally agree with your suggestions to > STP

Re: [PATCH] arm64: insn: Simulate nop and push instruction for better uprobe performance

Hi, Mark My bad for taking so long to rely, I generally agree with your suggestions to STP emulation. 在 2024/8/15 17:58, Mark Rutland 写道: > On Wed, Aug 14, 2024 at 08:03:56AM +, Liao Chang wrote: >> As Andrii pointed out, the uprobe/uretprobe selftest bench run into a >> counterintuitive resu

Re: [PATCH] arm64: insn: Simulate nop and push instruction for better uprobe performance

On Thu, Aug 15, 2024 at 2:58 AM Mark Rutland wrote: > > On Wed, Aug 14, 2024 at 08:03:56AM +, Liao Chang wrote: > > As Andrii pointed out, the uprobe/uretprobe selftest bench run into a > > counterintuitive result that nop and push variants are much slower than > > ret variant [0]. The root ca

Re: [PATCH] arm64: insn: Simulate nop and push instruction for better uprobe performance

On Wed, Aug 14, 2024 at 08:03:56AM +, Liao Chang wrote: > As Andrii pointed out, the uprobe/uretprobe selftest bench run into a > counterintuitive result that nop and push variants are much slower than > ret variant [0]. The root cause lies in the arch_probe_analyse_insn(), > which excludes 'no

[PATCH] arm64: insn: Simulate nop and push instruction for better uprobe performance

As Andrii pointed out, the uprobe/uretprobe selftest bench run into a counterintuitive result that nop and push variants are much slower than ret variant [0]. The root cause lies in the arch_probe_analyse_insn(), which excludes 'nop' and 'stp' from the emulatable instructions list. This force the k