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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5AE98C433EF for ; Wed, 30 Mar 2022 08:19:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229816AbiC3IVJ (ORCPT ); Wed, 30 Mar 2022 04:21:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244350AbiC3IU4 (ORCPT ); Wed, 30 Mar 2022 04:20:56 -0400 Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99FD23121D for ; Wed, 30 Mar 2022 01:19:06 -0700 (PDT) Received: by mail-ej1-x62b.google.com with SMTP id dr20so39874989ejc.6 for ; Wed, 30 Mar 2022 01:19:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=pb8rc4LHPVXRF45q6Y/HA0FDcpsgWdrRhkyzNeOLHxI=; b=hMxR9tr3eiF29WJjn89DiiTlkXVbXxsieJNuInPomBEsdtmFP9bESHFFaToBZJ/rwT pM+NVBYzt0T3xlO4o2/sD++iWhR1FH6zDmIL6hLxsmSi7JAAt72Gce0ZtV+6FPZbs+lG QI5T+b863kT+f6e0VzFBLDxgTjkQAv0x0d+aE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=pb8rc4LHPVXRF45q6Y/HA0FDcpsgWdrRhkyzNeOLHxI=; b=Z5d6nPWIvafOOLSNDKqTDE72FP1fs2U0coKGqxmbiH0YLo1DzeWoGXlBn80PRpb2Xu q3l1kw1hAozPMXVk3uh9fJ8NCFPtFN0orAjlXdY/oyHpGhT11L4SsIdN3MdXw2Q5/b2B pqxeHVrU+FwDMpAyIf6ZivRyY2mfCmNe8nOpcahSDdFR9C624EC8x0XZjGSP2ojMEeHt 2qgUIChJhjATX4X5L1tnPv+8mu1RvIE/XnrRnNdzaUZdrN69kobzbFQmFjo9xv0E+Nnn QMGEikFd/a1faNxvyJZn8fmiSIpmCmHr295mKXZifYkhVD2viea3TvOzoCAjK413r85h SRow== X-Gm-Message-State: AOAM533pEH9agA5nf/8jSMFwW8UZoSEIL5qSKzid3Oyphu5c6zxpj0OK sdFCTrNdhUR6iwvF9edlwjK7pHDuF5/xqVoJ86PWdVAGJx8= X-Google-Smtp-Source: ABdhPJwM+3OjeVOZ4Zf15dUolvoMFuQLA/OMsKn1zj5rwTWIc7I12GndA3vOgZhoQW9Gq8VEV/4ExobEe4akDci1q5k= X-Received: by 2002:a17:906:7948:b0:6da:64ed:178e with SMTP id l8-20020a170906794800b006da64ed178emr39588464ejo.523.1648628345183; Wed, 30 Mar 2022 01:19:05 -0700 (PDT) MIME-Version: 1.0 References: <8145e724-d960-dd85-531e-16e564a02f05@kernel.dk> <115fc7d1-9b9c-712b-e75d-39b2041df437@kernel.dk> <89322bd1-5e6f-bcc6-7974-ffd22363a165@kernel.dk> <0c5745ab-5d3d-52c1-6a1d-e5e33d4078b5@kernel.dk> In-Reply-To: <0c5745ab-5d3d-52c1-6a1d-e5e33d4078b5@kernel.dk> From: Miklos Szeredi Date: Wed, 30 Mar 2022 10:18:54 +0200 Message-ID: Subject: Re: io_uring_prep_openat_direct() and link/drain To: Jens Axboe Cc: io-uring@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Tue, 29 Mar 2022 at 22:03, Jens Axboe wrote: > Can you try and repull the branch? I rebased the top two, so reset to > v5.17 first and then pull it. This one works in all cases, except if there's a link flag on the read. In that case the read itself will succeed but following requests on the link chain will fail with -ECANCELED. > BTW, I would not recommend using DRAIN, it's very expensive compared to > just a link. Particularly, using just a single link between the > open+read makes sense, and should be efficient. Don't link between all > of them, that's creating a more expensive dependency that doesn't make > any sense for your use case either. Should they both work? Of course, > and I think they will in the current branch. Merely stating that they > make no sense other than as an exercise-the-logic test case. Understood. Once all of these cases work, it should be possible to compare the performance of parallel vs. serial execution. Thanks, Miklos