From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 40A4E271A9A for ; Wed, 19 Nov 2025 02:55:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763520945; cv=none; b=Ja/BARXks5xX9PqxpTSrVvMgaesH9XArStEJ0oY1KCXhhPWPNxClWd+C7Ta0+z8SzF8nQcb1DRuPrPgZ8sDWM1gBy9f54p4fYZTaIB/H6E0fNThNuB0lgz8E4vPzIerl3qVlMjKiJm4JCH46LheVo+hEoaPXQwoIYcfT8iybfDc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763520945; c=relaxed/simple; bh=dVSDNy+DPQdDSMwW6icZnlkNgzbJHoHYB4a8VWDsAaU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=kwKBpUlyooRciddyGx/Pzde7REbnxOKtR7obK/s2/YuWhsbrPMXV/dXcyINhwojRNDLY7trkucLlXmz1bA7ruRdj2hcWTLjQUpKlWOBPj/nth8/AfG4SNNhkyapZlljQphkgRbzaDh0nTkY4YPKzjDD+t5ybywMZRf4xrocaTto= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=iI0K4CF8; arc=none smtp.client-ip=91.218.175.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="iI0K4CF8" Message-ID: <97c8e49c-ca27-40ec-8ff6-18b1b9061240@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1763520931; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YYOi8yKGJknMfqscK3XJCAosx9iyRQ0/XGaFEVpfjzk=; b=iI0K4CF8Yr+i4/s9Pl3AduYCV/WxD98Z+hw06/lA6hsyefYszHcJLJjA4oPzsOYmlxI4Lm hB8pq7oi6iV3gbGzt1q+EngKeY+IKHYZ87cl5KySiGKSs/GxeOp7C9NaTRMdZvM+dfQzoP OQv/BxKHxn7r5OUp+DL3zZX8e7CysLU= Date: Wed, 19 Nov 2025 10:55:19 +0800 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v3 0/6] bpf trampoline support "jmp" mode Content-Language: en-US To: Menglong Dong , Menglong Dong , Alexei Starovoitov , Leon Hwang Cc: Alexei Starovoitov , Steven Rostedt , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Eduard , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , jiang.biao@linux.dev, bpf , LKML , linux-trace-kernel References: <20251118123639.688444-1-dongml2@chinatelecom.cn> <8606158.T7Z3S40VBb@7950hx> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Leon Hwang In-Reply-To: <8606158.T7Z3S40VBb@7950hx> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 19/11/25 10:47, Menglong Dong wrote: > On 2025/11/19 08:28, Alexei Starovoitov wrote: >> On Tue, Nov 18, 2025 at 4:36 AM Menglong Dong wrote: >>> >>> As we can see above, the performance of fexit increase from 80.544M/s to >>> 136.540M/s, and the "fmodret" increase from 78.301M/s to 159.248M/s. >> >> Nice! Now we're talking. >> >> I think arm64 CPUs have a similar RSB-like return address predictor. >> Do we need to do something similar there? >> The question is not targeted to you, Menglong, >> just wondering. > > I did some research before, and I find that most arch > have such RSB-like stuff. I'll have a look at the loongarch > later(maybe after the LPC, as I'm forcing on the English practice), > and Leon is following the arm64. Yep, happy to take this on. I'm reviewing the arm64 JIT code now and will experiment with possible approaches to handle this as well. Thanks, Leon > > For the other arch, we don't have the machine, and I think > it needs some else help. > > Thanks! > Menglong Dong