From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 44B99F9D0F6 for ; Tue, 14 Apr 2026 20:44:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:References: Subject:To:From:Cc:Message-Id:Date:Content-Type:Content-Transfer-Encoding: Mime-Version:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=L8bWJr7FXUdlTXBxL69DdsJ20JowQnELYHkBWQ0j71o=; b=SgkfaqZ4D1Sp10jQkR0AP4tfGI xzSvdsqlGqEvrzJBD0SDfiHqUvqwCQJQVQhzZ7+RVk0WKc7Qz38OeQn6p+Z5Wz50QuGN8zR64eEnW lU7sy82EGU+bTAm+FqI8t6QR48jrli5urpj+PdgA2zucEhz+N3VoSv1EALAwVA50gUDrDhBueeiFl zVXLZCAyWQ+xAFwMU5ko9pcRlI3SlvqZsl90jFo3JS9CycfD7oTgA/J57ljk5QyAdsvwoNyOmqm5H 6gbKYkblZuSKRL1PTSKALvQC+rbGz+MzT+ITLNTMLjwoseBmTnVhSPmWIgG/kssC6dS8YO/I/NKjx YxLA37yA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wCkce-00000000CyA-0cF8; Tue, 14 Apr 2026 20:44:36 +0000 Received: from smtpout-04.galae.net ([185.171.202.116]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wCkca-00000000Cxj-0Jbo for linux-arm-kernel@lists.infradead.org; Tue, 14 Apr 2026 20:44:34 +0000 Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id 36C6FC5AAB7; Tue, 14 Apr 2026 20:45:05 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id CCCED60410; Tue, 14 Apr 2026 20:44:27 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 4D13710450F98; Tue, 14 Apr 2026 22:44:13 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1776199466; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=L8bWJr7FXUdlTXBxL69DdsJ20JowQnELYHkBWQ0j71o=; b=tp0oFwTf5VHzsnEQcoI6YFXubpXr48s6UWlXK4aDR8EDMSSF+/OjNf6hUwJE2BAbHAdgPz v2f4A8tTxVtK7dqJZfFAdjP+hWDl0Fam9eGGy91tNDrdqr1jGCVU5mlUKQsx7dKkw5Fj/o 8xB9Inm9XOYYzG+OqKhmNW03MF+ALRZMBSynxDWIF5QBxopuN97KxRbIxhOyfKSB9o6wkS 91454gD3J6J7wN/TaEOT0JgO64Dp+ztksnjtLIOwoMGIkVJ9RQPJZYo6iGmJA9iAtEHlyl YSu689PmkWekOvBlF+bpB2iuXK1nNSBHe1tFVeClAIGo4vy+Vjuo6lCfP898kw== Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Tue, 14 Apr 2026 22:44:13 +0200 Message-Id: Cc: "Andrey Konovalov" , "Alexei Starovoitov" , "Daniel Borkmann" , "Andrii Nakryiko" , "Martin KaFai Lau" , "Eduard Zingerman" , "Kumar Kartikeya Dwivedi" , "Song Liu" , "Yonghong Song" , "Jiri Olsa" , "John Fastabend" , "David S. Miller" , "David Ahern" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "Dave Hansen" , "X86 ML" , "H. Peter Anvin" , "Shuah Khan" , "Maxime Coquelin" , "Alexandre Torgue" , "Andrey Ryabinin" , "Alexander Potapenko" , "Dmitry Vyukov" , "Vincenzo Frascino" , "Andrew Morton" , , "Bastien Curutchet" , "Thomas Petazzoni" , "Xu Kuohai" , "bpf" , "LKML" , "Network Development" , "open list:KERNEL SELFTEST FRAMEWORK" , , "linux-arm-kernel" , "kasan-dev" , "linux-mm" From: =?utf-8?q?Alexis_Lothor=C3=A9?= To: "Alexei Starovoitov" , =?utf-8?q?Alexis_Lothor=C3=A9?= Subject: Re: [PATCH RFC bpf-next 1/8] kasan: expose generic kasan helpers X-Mailer: aerc 0.21.0-0-g5549850facc2 References: <20260413-kasan-v1-0-1a5831230821@bootlin.com> <20260413-kasan-v1-1-1a5831230821@bootlin.com> In-Reply-To: X-Last-TLS-Session-Version: TLSv1.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260414_134432_403136_90A1F050 X-CRM114-Status: GOOD ( 17.00 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue Apr 14, 2026 at 9:16 PM CEST, Alexei Starovoitov wrote: > On Tue, Apr 14, 2026 at 11:41=E2=80=AFAM Alexis Lothor=C3=A9 > wrote: >> >> On Tue Apr 14, 2026 at 4:36 PM CEST, Alexei Starovoitov wrote: >> > On Tue, Apr 14, 2026 at 6:13=E2=80=AFAM Alexis Lothor=C3=A9 >> > wrote: >> >> >> >> Hi Andrey, thanks for the prompt review ! [...] >> > No. The performance penalty will be too high. >> >> Since we are mentioning it, I did not consider yet any performance >> comparision/benchmarking (and I am not really familiar with usual bpf >> performance validation practices for new bpf features). Is there any >> existing test I should take a look at for this ? Maybe some specific >> benches in tools/testing/selftests/bpf/bench ? > > So far everything in bpf/bench/ measures bpf infra like > maps, kprobes, tracepoints, etc. > We don't have benchmarks for bpf programs. > So we don't know how well JITs are generating code > and how much inlining done by the verifier, JITs actually helps. > > Puranjay is working on creating a SPECint like set of benchmarks. > > For this kasan work we should make the best decisions from > performance point of view, like not wasting unnecessary call > and not saving unnecessary registers. btw in the other patch > I think you can skip saving of r10 and r11. Noted, I'll do some checks and tests without those two. > But we cannot quantify yet that avoiding extra call gives us N%. > > You can micro-benchmark, of course, but gotta be careful > interpreting the results. It might be too easy to get into > thinking that JIT must inline __asan_load() for the sake of performance. Ok, interesting, thanks for those details Alexis --=20 Alexis Lothor=C3=A9, Bootlin Embedded Linux and Kernel engineering https://bootlin.com