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 CDBA52D949F; Wed, 26 Aug 2026 04:40:19 +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=1787719223; cv=none; b=XStdRO/1vg5Ohv/aIvyMk+0281ts54g0UpCRpqq2Y7Le7v8pLFTRcQmawZOhnAqccG01EA0M7cxxjvdgnMwo8ZTuAz0TgMd5AJj/sEv0hjlHMuynQvYizX0YMFPGJhrQuC+YfCKGj3Urm4eRnWRRKNGDKirVig71Pw8ASuDLZHs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787719223; c=relaxed/simple; bh=rbnxXlzusyU4DUcwC+ND9+vQQAbDhdLUTY4nmbnDm/Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Jr9rb3utJ0ZrpzR62Uyg2oIAReFJ2EYk9VnTKw2wqCIpLS8iRlAeAkMEDHqQGhgxgAk9I1ap3eFOKVhVWx1wHXMiUD7T89PChm+/tn5uorDqYcVxaZu0/CWaj7/+11HHfbE9kevEB6jYx75nD8PoOD4/LX5BD/UHqWfoWr7SEXI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (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=VoI+GkCl; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (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="VoI+GkCl" 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=p30MTcyBufrYNaiv6371E/aWtzY2AMPq8/F5SxBlSWY=; b=VoI+GkClDOoGUmjNfMfDHZlhB2 D7aokuzXE2a9itGcHUTN7SKZVpdvicblAu9CiOSN0ZUHtM+yLyl+LpKAOjB7OBf4j0N2r0Ihw26Z0 MnjagqaJRhN9ZAOu1ZPy8OmG077a7DNJibK3Pxpv2TwX0m4wOGBReWvOnQhhtZxa8EFFg9kSfuMVx r/4CeymiqvUyYNDZjvOHmBoOUJT5gRES+eFC3BBPFKYto8hpLyE1/XaiJ2HK+TRRI4GBSXWI9vdUA 0JgF0nRBSMEYVbc7NOcgvwRKCaZ8BAZf4UXFwwyWn1n5rMkIAsrn0jWXkEklBqgGt1WG0ck55GC69 e1HQxhLw==; Received: from hch by bombadil.infradead.org with local (Exim 4.99.1 #2 (Red Hat Linux)) id 1wz5Qx-00000001tNt-0oEC; Wed, 26 Aug 2026 04:40:19 +0000 Date: Tue, 25 Aug 2026 21:40:19 -0700 From: Christoph Hellwig To: David Timber Cc: Christoph Hellwig , OGAWA Hirofumi , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [RFC PATCH] fat: add noflush mount option Message-ID: References: <20260822173732.10230-1-dxdt@dev.snart.me> 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: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Wed, Aug 26, 2026 at 01:13:29PM +0900, David Timber wrote: > It probably had something to do with DOS and/or Windows implementation, > maybe a "monkey see, monkey do" situation. I think this is why FAT on > Windows is quite slow to this day(again, I might be wrong so don't quote > me on this). > > Whoever first came up with the idea was probably worried too much about > users(who are not familiar with UNIX systems) unplugging removable > devices without giving the OS an opportunity to sync. I have to say > that, compared to Windows' default behaviour, the default 5 seconds of > vm.dirty_writeback is quite aggressive and that's why we have the flush > option in the first place... > > But I still think being able to flip the option on the fly should come > in really handy in embedded systems that just can't afford to do > explicit sync. As I said, no objection to adding the option, but I think addressing the root cause in addition would be very helpfu.