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 X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8352C56201 for ; Tue, 24 Nov 2020 21:58:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80B5F20715 for ; Tue, 24 Nov 2020 21:58:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731713AbgKXV6I (ORCPT ); Tue, 24 Nov 2020 16:58:08 -0500 Received: from www62.your-server.de ([213.133.104.62]:37058 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731696AbgKXV6I (ORCPT ); Tue, 24 Nov 2020 16:58:08 -0500 Received: from sslproxy06.your-server.de ([78.46.172.3]) by www62.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92.3) (envelope-from ) id 1khgK4-0007RJ-L4; Tue, 24 Nov 2020 22:58:04 +0100 Received: from [85.7.101.30] (helo=pc-9.home) by sslproxy06.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1khgK4-000Bqf-Fk; Tue, 24 Nov 2020 22:58:04 +0100 Subject: Re: [PATCH][V2] libbpf: add support for canceling cached_cons advance To: Magnus Karlsson , Li RongQing Cc: Network Development , bpf , "Karlsson, Magnus" References: <1606202474-8119-1-git-send-email-lirongqing@baidu.com> From: Daniel Borkmann Message-ID: Date: Tue, 24 Nov 2020 22:58:03 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.102.4/25998/Tue Nov 24 14:16:50 2020) Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 11/24/20 9:12 AM, Magnus Karlsson wrote: > On Tue, Nov 24, 2020 at 8:33 AM Li RongQing wrote: >> >> Add a new function for returning descriptors the user received >> after an xsk_ring_cons__peek call. After the application has >> gotten a number of descriptors from a ring, it might not be able >> to or want to process them all for various reasons. Therefore, >> it would be useful to have an interface for returning or >> cancelling a number of them so that they are returned to the ring. >> >> This patch adds a new function called xsk_ring_cons__cancel that >> performs this operation on nb descriptors counted from the end of >> the batch of descriptors that was received through the peek call. >> >> Signed-off-by: Li RongQing >> [ Magnus Karlsson: rewrote changelog ] >> Cc: Magnus Karlsson >> --- >> diff with v1: fix the building, and rewrote changelog >> >> tools/lib/bpf/xsk.h | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h >> index 1069c46364ff..1719a327e5f9 100644 >> --- a/tools/lib/bpf/xsk.h >> +++ b/tools/lib/bpf/xsk.h >> @@ -153,6 +153,12 @@ static inline size_t xsk_ring_cons__peek(struct xsk_ring_cons *cons, >> return entries; >> } >> >> +static inline void xsk_ring_cons__cancel(struct xsk_ring_cons *cons, >> + size_t nb) >> +{ >> + cons->cached_cons -= nb; >> +} >> + >> static inline void xsk_ring_cons__release(struct xsk_ring_cons *cons, size_t nb) >> { >> /* Make sure data has been read before indicating we are done >> -- >> 2.17.3 > > Thank you RongQing. > > Acked-by: Magnus Karlsson @Magnus: shouldn't the xsk_ring_cons__cancel() nb type be '__u32 nb' instead? Thanks, Daniel