From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (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 6F5CB14F9D6; Wed, 10 Dec 2025 02:57:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765335433; cv=none; b=ONWVNrV4E1pcu3FrV+9Q50djtjaMscAB7yO3r9RXDvA/FAyFRmOUhjSvEWvuk8R4bSe1K38zFapPF2hpxPg/2zUS2z6GVG/5dNwSUhanpV7GErPICTNJkqvzPbE9mYibgIgVZX9Q/9O2hqlOUlzGUfOu9lUea62p1fnx9/ZzOn8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765335433; c=relaxed/simple; bh=7m01CPyoeViz6pIdG5hXSEjykElVTEe/TyNdLPtOx9w=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=Iw07q4ehok1Qi56vFRY6rplN/a0UmOKytfRKtQHUz3mLDw6sJPjvb94zkbkSAGfLOjNadtQ3h1YgNTJS651u6FkHhPcV+IUvtQGLqBFpIX4JcHXZIxA6XfdCQFNYyQZIeAVfukpi6wwISDTShkr42Lm/4WTNGvwHix4SMQWkaXg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=UF5ocA7x; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=UF5ocA7x; arc=none smtp.client-ip=45.249.212.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="UF5ocA7x"; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="UF5ocA7x" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=kHGQxXud0RlcL7IpHDIbVN/X32saQFfy4JvgH1aEGzU=; b=UF5ocA7xKojVjMCJX9X7yvttQfUBxknqB2GtiVOUWKX+DVfTk3aRc09+2hAmyPsw4jWLS/GAW qs5Mib4O1Tr77+cs4cmkurD3UGPXqSwXxDqiYYgknE4cNLZMvEtgl4foR6sojBCzSXLxEVFZbfe b8jwIWJ7upumvXbfTcqGH7U= Received: from canpmsgout04.his.huawei.com (unknown [172.19.92.133]) by szxga01-in.huawei.com (SkyGuard) with ESMTPS id 4dR0k15zwdz1BFnW; Wed, 10 Dec 2025 10:56:57 +0800 (CST) dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=kHGQxXud0RlcL7IpHDIbVN/X32saQFfy4JvgH1aEGzU=; b=UF5ocA7xKojVjMCJX9X7yvttQfUBxknqB2GtiVOUWKX+DVfTk3aRc09+2hAmyPsw4jWLS/GAW qs5Mib4O1Tr77+cs4cmkurD3UGPXqSwXxDqiYYgknE4cNLZMvEtgl4foR6sojBCzSXLxEVFZbfe b8jwIWJ7upumvXbfTcqGH7U= Received: from mail.maildlp.com (unknown [172.19.88.194]) by canpmsgout04.his.huawei.com (SkyGuard) with ESMTPS id 4dR0gm5kPKz1prKr; Wed, 10 Dec 2025 10:55:00 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id 60D1014022E; Wed, 10 Dec 2025 10:56:58 +0800 (CST) Received: from [10.67.109.254] (10.67.109.254) by dggpemf500011.china.huawei.com (7.185.36.131) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 10 Dec 2025 10:56:57 +0800 Message-ID: <132ceb8f-e82d-bed7-7b93-41f5dd505a03@huawei.com> Date: Wed, 10 Dec 2025 10:56:56 +0800 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Subject: Re: [PATCH v9 14/16] arm64: Inline el0_svc_common() To: Kevin Brodsky , , , , , , , , , , , , , , , , , , , , , , , , References: <20251204082123.2792067-1-ruanjinjie@huawei.com> <20251204082123.2792067-15-ruanjinjie@huawei.com> <746211f0-74b7-4935-a036-48a00bb5701b@arm.com> Content-Language: en-US From: Jinjie Ruan In-Reply-To: <746211f0-74b7-4935-a036-48a00bb5701b@arm.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems100002.china.huawei.com (7.221.188.206) To dggpemf500011.china.huawei.com (7.185.36.131) On 2025/12/9 21:48, Kevin Brodsky wrote: > On 04/12/2025 09:21, Jinjie Ruan wrote: >> After switch arm64 to Generic Entry, the compiler no longer inlines > > Did it inline it before this series? Yes, as below : d503201f nop d503201f nop d503233f paciasp a9be7bfd stp x29, x30, [sp, #-32]! 910003fd mov x29, sp a90153f3 stp x19, x20, [sp, #16] aa0003f3 mov x19, x0 d5384114 mrs x20, sp_el0 f9400001 ldr x1, [x0] f9400282 ldr x2, [x20] f9008801 str x1, [x0, #272] f9402001 ldr x1, [x0, #64] b9011801 str w1, [x0, #280] 373001e2 tbnz w2, #6, ffff80008002c0f0 f278105f tst x2, #0x1f00 54000261 b.ne ffff80008002c108 // b.any 52803ac2 mov w2, #0x1d6 // #470 97ffffb1 bl ffff80008002bf88 f9400280 ldr x0, [x20] 92783400 and x0, x0, #0x3fff00 926bdc00 and x0, x0, #0xffffffffffe01fff b4000060 cbz x0, ffff80008002c0e0 aa1303e0 mov x0, x19 97ffc835 bl ffff80008001e1b0 a94153f3 ldp x19, x20, [sp, #16] a8c27bfd ldp x29, x30, [sp], #32 d50323bf autiasp d65f03c0 ret 92804000 mov x0, #0xfffffffffffffdff // #-513 f9000260 str x0, [x19] a94153f3 ldp x19, x20, [sp, #16] a8c27bfd ldp x29, x30, [sp], #32 d50323bf autiasp d65f03c0 ret 3100043f cmn w1, #0x1 54000140 b.eq ffff80008002c134 // b.none aa1303e0 mov x0, x19 97ffc7c1 bl ffff80008001e018 2a0003e1 mov w1, w0 3100041f cmn w0, #0x1 54fffdc0 b.eq ffff80008002c0d8 // b.none aa1303e0 mov x0, x19 52803ac2 mov w2, #0x1d6 // #470 97ffff97 bl ffff80008002bf88 17ffffea b ffff80008002c0d8 928004a0 mov x0, #0xffffffffffffffda // #-38 f9000260 str x0, [x19] 17fffff5 b ffff80008002c110 d53cd044 mrs x4, tpidr_el2 d53cd040 mrs x0, tpidr_el2 d53cd041 mrs x1, tpidr_el2 00000000 udf #0 d503201f nop d503201f nop > >> el0_svc_common() into do_el0_svc(). So inline el0_svc_common() and it >> has 1% performance uplift on perf bench basic syscall on kunpeng920 >> as below. >> >> | Metric | W/O this patch | With this patch | Change | >> | ---------- | -------------- | --------------- | --------- | >> | Total time | 2.195 [sec] | 2.171 [sec] | ↓1.1% | >> | usecs/op | 0.219575 | 0.217192 | ↓1.1% | >> | ops/sec | 4,554,260 | 4,604,225 | ↑1.1% | >> >> Signed-off-by: Jinjie Ruan > > I think this is sensible - do_el0_svc() is clearly hot and the small > increase in code size is completely justified. It also removes a > performance regression when enabling CONFIG_COMPAT (without it > el0_svc_common() has only one caller so it should be inlined regardless). > > Reviewed-by: Kevin Brodsky > >> --- >> arch/arm64/kernel/syscall.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c >> index 47e193a1cfff..5aa51da9ec25 100644 >> --- a/arch/arm64/kernel/syscall.c >> +++ b/arch/arm64/kernel/syscall.c >> @@ -66,8 +66,8 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno, >> choose_random_kstack_offset(get_random_u16()); >> } >> >> -static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, >> - const syscall_fn_t syscall_table[]) >> +static __always_inline void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, >> + const syscall_fn_t syscall_table[]) >> { >> unsigned long work = READ_ONCE(current_thread_info()->syscall_work); >> unsigned long flags = read_thread_flags(); >