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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 B5B4FC10F00 for ; Sat, 16 Mar 2019 01:38:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 849BE218D4 for ; Sat, 16 Mar 2019 01:38:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552700308; bh=UfFW7mLzJCigZNffhJkds2/ebDEpdTrZ4sYz0cQb2x4=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=OvIDJ+0bN3UOCTVs7qQA1SUvF1680EUq4pHRSJVtniIAziMn96lddhZQ1iNT5RR2L 6XlNyeGxGaSvYS/Avl+rBtMh9C+FlMENHqF10VifzveFPsJJwS6b5EpEE6IYYNzFeV OiPVbb4V0XhMp2/xwM0R4h6QFOYtBegIj0A98XLI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726465AbfCPBez (ORCPT ); Fri, 15 Mar 2019 21:34:55 -0400 Received: from mail-lj1-f193.google.com ([209.85.208.193]:46862 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726204AbfCPBez (ORCPT ); Fri, 15 Mar 2019 21:34:55 -0400 Received: by mail-lj1-f193.google.com with SMTP id z26so9249896lja.13 for ; Fri, 15 Mar 2019 18:34:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=M13FtalC3wZiHNHMJnwtA/ImIg3BtGJsLIdUZ4w922s=; b=JvKFCw8qtw+zh3eSsBizhTIYBj7b56eSYlVoyKQwEQy4YhrvSWjlCB9eVruuhcv7c3 z2S+DmI4J9kzpLD9PrdSGVIhq8L1n4PMD/uWeddTfJKN1OroAXybx0L0ar2p0muzh5+C tyZVrheLABSoPJARbL9vPHlZuhzYoutN8vA2s= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=M13FtalC3wZiHNHMJnwtA/ImIg3BtGJsLIdUZ4w922s=; b=hmN6HdreX19t+3spYKD3xKRHpdVNM22a3djrwJyef4QBBVzCHTENlcMwmbpJvcpsjp owiFXKlENxq0O+NzMh70k9IayVV5BVz4Nh1RbQzDh/r2KrvWpOWl8LE6yz3f7YCChIKw OB3Vj/gOsk4zr4nx8ml7PMnUvZugE2OJkJbBzLPTb/LR0WtNhke9p+40d8eiplxYAbdZ UcidA4NLijmMfCJJXRVvNynmt2FoCwQuU1udNzAV/s068Ca1VXyrDSDv4qF05DaDKemk B6v2V/16x4rUV/o/7KR1WEIucpzajSqMd2jUb+GQOwZKRfwZUiavIciA6YIDkYoritSD qZyQ== X-Gm-Message-State: APjAAAXeqCQbWRtZ7cG0U4+oWf3GbGaMS7TCV2kIs3w3ooT0YnlQcxs1 bTpCBnqdlpQfuvl78sHwxTaWGhjtzYE= X-Google-Smtp-Source: APXvYqzKiRhnDXhmtYihee2APsPBgDyc6/4XL0MLFhvpbh/BcnPJKzeUk1yS/+OyaJy5vgOhZe8KvQ== X-Received: by 2002:a2e:7817:: with SMTP id t23mr4059587ljc.174.1552700092969; Fri, 15 Mar 2019 18:34:52 -0700 (PDT) Received: from mail-lf1-f50.google.com (mail-lf1-f50.google.com. [209.85.167.50]) by smtp.gmail.com with ESMTPSA id g68sm728993ljg.53.2019.03.15.18.34.51 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Mar 2019 18:34:51 -0700 (PDT) Received: by mail-lf1-f50.google.com with SMTP id h6so8112102lfc.2 for ; Fri, 15 Mar 2019 18:34:51 -0700 (PDT) X-Received: by 2002:ac2:424c:: with SMTP id m12mr3927188lfl.62.1552700091266; Fri, 15 Mar 2019 18:34:51 -0700 (PDT) MIME-Version: 1.0 References: <20190315145938.21516-1-axboe@kernel.dk> <20190315145938.21516-4-axboe@kernel.dk> In-Reply-To: From: Linus Torvalds Date: Fri, 15 Mar 2019 18:34:35 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 3/3] io_uring: add io_uring_event cache hit information To: Jens Axboe Cc: linux-fsdevel , linux-block , Al Viro Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Mar 15, 2019 at 9:27 AM Jens Axboe wrote: > > Linus, curious on your opinion on this one. I had this as part of the > original series, but removed it from the pull request due to the > mincore etc discussions. I'd rather not have new ways to leak cache information, and in fact already the IOCB_NOWAIT is a bit questionable for that. But afaik, the non-O_DIRECT paths don't even support it to begin with for some filesystems. Wasn't the whole point of this io_ring that we'd move *away* from direct block access and O_DIRECT? I'm seeing a lot of stuff that looks like just "more of the same old O_DIRECT garbage" that seems to be all about thinking that IO doesn't cache. Haven't we gotten over that already? It was one of the arguments you used for io_ring to begin with. Linus