From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id 262461B3F3D for ; Wed, 16 Oct 2024 07:36:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729064183; cv=none; b=S0BWA25OLTzGAN5extUhqE6YuPs9FdCnm5aSyDQqZ1oSHWR+9zqZ8fCbntOytMoIFsXMg0EE0NaNvIAM7YxDY+li6v30Myn3zkNph1ZmCuxozVTrioHfTVzMcE2C0IQtsxSyTylZhmrdiYwGw6cFwuBlpc/+BwQtpMqM6U/6xGM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729064183; c=relaxed/simple; bh=qx8dj+f9N6uYx22MEEruzzPfngnsd0i0W/nabdG51DE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BjzGvHhDiK+fdldEupimhGgZvEVXsuiljgd9DwHvpeAQtnwlsb/jpVtL/J3xuIHcyw3Jscc7jL7uTMOfeLeKQ50IBmxIQ83nEnlGX0iBcxdCMTsCgWs8AQWoAozFUSqSvv2qbI9YuAoMqOPoyxCwEfrpMjGoFThUCWpj9Ej6nS4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=old0oer5; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="old0oer5" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=OafRmAoHaK4TM/K6ajx4rHrM446tv8IYnsqz/V3KSbE=; b=old0oer5HSG2XSScMMNJQaRo2i y47AgEasnlPpAClTk6CI6RNJvzocjwE5tgA0g3sHpIw43RrqK/JZuL1tNEkIGK4AEilba9mKJs3Zp NTMMdCXOQqdGvqQa3cV3WTUzPNE+fxJ5iof98SOEffEIt+faObHdLozRYs6R60RF48kscZgmydiJ3 WOT1Vhq8b7ieyIFse5/CCFm45Wz5WdhLI9QSQ+MNYr/7mZ/8PPeTYJZICGBnE1m67G5/ZTNTNZeyc L7t8MzguY8xBskWz2SwyOGapP50Za4unOtyH07/Rd/tiTkqirUTb5carnwiZv6YmpAHc0XyYFcCpm FuYgaeQg==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1t0yZv-0000000AqVh-2uVJ; Wed, 16 Oct 2024 07:36:19 +0000 Date: Wed, 16 Oct 2024 00:36:19 -0700 From: Christoph Hellwig To: lizhe.67@bytedance.com Cc: hch@infradead.org, akpm@linux-foundation.org, boqun.feng@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, longman@redhat.com, mingo@redhat.com, peterz@infradead.org, will@kernel.org Subject: Re: [RFC 1/2] rwsem: introduce upgrade_read interface Message-ID: References: <20241016073340.42565-1-lizhe.67@bytedance.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241016073340.42565-1-lizhe.67@bytedance.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Wed, Oct 16, 2024 at 03:33:40PM +0800, lizhe.67@bytedance.com wrote: > >> +extern int upgrade_read(struct rw_semaphore *sem); > > > >No need for the extern. Also please make any new advanced funtionality > > Sorry I don't understand why extern is not needed. If we remove it, > we will encounter the following compilation error: That sounds like you dropped the entire line above, and not just the "extern ".