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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38E0CC3ABBF for ; Tue, 6 May 2025 13:37:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0F4356B0095; Tue, 6 May 2025 09:37:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0A3FB6B0096; Tue, 6 May 2025 09:37:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ED4ED6B0098; Tue, 6 May 2025 09:37:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id CEF5C6B0095 for ; Tue, 6 May 2025 09:37:14 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id F1C06C0280 for ; Tue, 6 May 2025 13:37:15 +0000 (UTC) X-FDA: 83412584430.28.3FCCD25 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf28.hostedemail.com (Postfix) with ESMTP id 2A4D0C0005 for ; Tue, 6 May 2025 13:37:13 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=lst.de; spf=pass (imf28.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1746538634; a=rsa-sha256; cv=none; b=J3IKynsccfCqL0v5ZuvzBJsP5sf/ykCibTa+UJbBWN5D6fG9jRh2HxtgN8O2sgt9voAyHq BTWkNyiaet8uZUMqIcIvkheMWrnHpR6+7xJ2Q4pEagGWrEbmttK7d2ruCj/fEeu52Am2Cv tsMBb+LjHJtOD1ihMGqZuqWKC2OeUzw= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=lst.de; spf=pass (imf28.hostedemail.com: domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1746538634; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5wXA5GOW/HgbHPUwV9W9TVbtlUhSe/gYcVFioukOYxY=; b=kQjIB/GJSkVjBkAGOLCKA/fyalOTom7SnWC05VJBtnWLsC14UZ8uYYO2f1zLK2lf+NuCC3 wnlkyOM8Pja2+gSV1GBSBR/Zf1zREPhbqgnGuLD8nRA827gdGsBnTlOItxfZ2Jo6u0hnkc jN8qyVh6HDCxLLuSucBz8hAYM4/w9eE= Received: by verein.lst.de (Postfix, from userid 2407) id 68FD168B05; Tue, 6 May 2025 15:37:07 +0200 (CEST) Date: Tue, 6 May 2025 15:37:06 +0200 From: Christoph Hellwig To: Herbert Xu Cc: Yosry Ahmed , Vitaly Wool , linux-mm@kvack.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Nhat Pham , Shakeel Butt , Johannes Weiner , Minchan Kim , Sergey Senozhatsky , Igor Belousov , Christoph Hellwig Subject: Re: [PATCH] mm/zblock: use vmalloc for page allocations Message-ID: <20250506133706.GA29215@lst.de> References: <20250502080156.1672957-1-vitaly.wool@konsulko.se> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 2A4D0C0005 X-Stat-Signature: kb1sr88fifgbw6iwy66kptp158c6aasx X-Rspam-User: X-HE-Tag: 1746538633-729362 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, May 06, 2025 at 09:27:49PM +0800, Herbert Xu wrote: > On Tue, May 06, 2025 at 01:13:17PM +0000, Yosry Ahmed wrote: > > > > Keep in mind that zswap_decompress() will always do an extra copy if the > > address returned by zpool_obj_read_begin() is a vmalloc address. To > > avoid this we need to enlighten the scatterlist API to work with vmalloc > > addresses. > > > > (CC'ing Herbert as he was looking into this) > > acomp now supports linear addresses so vmalloc can be sent through > directly. It will fail if you use hardware offload though since > you can't DMA directly to vmalloc virtual addresses. You absolutely can and lots of code does.