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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 308BEC433EF for ; Tue, 7 Sep 2021 15:04:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 14B32610D0 for ; Tue, 7 Sep 2021 15:04:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344865AbhIGPFZ (ORCPT ); Tue, 7 Sep 2021 11:05:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231362AbhIGPFY (ORCPT ); Tue, 7 Sep 2021 11:05:24 -0400 Received: from mail-vs1-xe32.google.com (mail-vs1-xe32.google.com [IPv6:2607:f8b0:4864:20::e32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 752AEC061575 for ; Tue, 7 Sep 2021 08:04:18 -0700 (PDT) Received: by mail-vs1-xe32.google.com with SMTP id a21so8552447vsp.12 for ; Tue, 07 Sep 2021 08:04:18 -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=TpfzW/PVwHf+0Rs6X2ui1kGNO3SDbejRkBUW3mGcmE0=; b=iAYGVOEGFEObQ+gSfZKdElr9BDoLbQsWmbfuiS3jtgzCULIU3XDKXXVM0XV7nMU0AT EoADEg//7Ir4RyNX8DBD/88yo8mSUf/IlPcRpZbQYM3JKFBg15oK/T9+tQ8GVVeEMz1q MBFC/k3xrIyY94VHS1Y2pJDNGJk9/BND3Euu0= 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=TpfzW/PVwHf+0Rs6X2ui1kGNO3SDbejRkBUW3mGcmE0=; b=iUMcikJ7SdGAKY5WMLBXP8knJ/y2QA8uaaGLeoGB127SZlkKZyc4WJ7vwBiC74+vJg 1l4ZdzMBaCQGVUgnRzATj5eYPuUz1Jnf9AMXvBCoAEXEWLFOH+Th9rnwYQJGzNattOb/ w5E2DqsLBMgNs1jbQ7Cfuoq5htSx3RDB0+FAIZfkLx5VJ2fbUyLQhQNt5BTLXncKhnFE t9aaizudXRoO0sdDZ60fHF7oepQTHzd18riIe8dEXWZYukj2kDtRwMYtu2FX/lR/vnAX wImYjrdtwyLOsHzsi/Ia3FefblL0PmkM/M+7CvpzITG6NhlNEsKxNFJU5M9OpYxFzunP aPeA== X-Gm-Message-State: AOAM5312Ez9s668thN3ss39Jj2UJ+8k3GeY5WdGbQI8XtTFqHOF5EOlr VhOboubKLFOUFwlDxH8jwpiKkScCpPjIXqgUe+k3HA== X-Google-Smtp-Source: ABdhPJwIERSjQ0+LJJhbH8wqnmfyydiAjQhlY/i0gsHol0tvwD/gQaUqSvu68Y8bSrwCkLGVQmJfQ/4FXIJEr30mGYM= X-Received: by 2002:a67:eb45:: with SMTP id x5mr9917911vso.19.1631027056058; Tue, 07 Sep 2021 08:04:16 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Miklos Szeredi Date: Tue, 7 Sep 2021 17:04:03 +0200 Message-ID: Subject: Re: [PATCH] fuse: Use kmap_local_page() To: Hao Peng Cc: linux-fsdevel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, 18 Aug 2021 at 09:48, Hao Peng wrote: > > >On Tue, Aug 17, 2021 at 11:42 PM Miklos Szeredi wrote: >> >> >On Tue, 17 Aug 2021 at 05:17, Hao Peng wrote: >> >> >> >> kmap_local_page() is enough. >> >> >This explanation is not enough for me to understand the patch. Please >> >describe in more detail. > > Due to the introduction of kmap_local_*, the storage of slots used for short-term mapping has > changed from per-CPU to per-thread. kmap_atomic() disable preemption, while kmap_local_*() > only disable migration. > There is no need to disable preemption in several kamp_atomic places used in fuse. > The detailed introduction of kmap_local_*d can be found here: > https://lwn.net/Articles/836144/ Can you please resubmit the patch with this explanation and without tab/space corruption? Thanks, Miklos