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 C74B7C3DA7F for ; Mon, 12 Aug 2024 08:27:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5AFB76B00CD; Mon, 12 Aug 2024 04:27:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5602D6B00CE; Mon, 12 Aug 2024 04:27:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 429C36B00CF; Mon, 12 Aug 2024 04:27:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 1F2F36B00CD for ; Mon, 12 Aug 2024 04:27:09 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 980CB16094B for ; Mon, 12 Aug 2024 08:27:07 +0000 (UTC) X-FDA: 82442913294.20.FC8B17B Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf01.hostedemail.com (Postfix) with ESMTP id 4289640016 for ; Mon, 12 Aug 2024 08:27:03 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=aX95ch9s; spf=none (imf01.hostedemail.com: domain of BATV+1668c479149319e18fad+7659+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+1668c479149319e18fad+7659+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1723451134; 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:dkim-signature; bh=DzGPShZj/dAovMXyzcD3HCKI8PXy5jIutKKEn0gvgMU=; b=rVdhRLOt6jle6bBSBRl5DSDikWWM6u1Mg4Bq58kT9Y9rfE84981BLX5tyhTyg3QENHOoyi tRVvR77l1ClHxfynccd/vj8GZXfWb5cKtbbuImX1j4c7za3tZsKZWzpD6j5lRRRQCQbvwj p2wLLVrRDcJsmI1ROSMb4xqAPbtuVRI= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=aX95ch9s; spf=none (imf01.hostedemail.com: domain of BATV+1668c479149319e18fad+7659+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+1668c479149319e18fad+7659+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1723451134; a=rsa-sha256; cv=none; b=8e1+P0lDdS+V183oZ0Vm1UNXQZcLMifFuOjWPskfajWmf5DHT1rVhS22KdP7eDadcBDbnm I30PR9tSxHe5VptyhchRt5b/OekQsxGNnNvAEJP/0CDJjxdzW1XmUuwGxJXRn/Wd0nkql0 hi7j6B+INuGr42e/nR8IieGjMECuh6g= 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=DzGPShZj/dAovMXyzcD3HCKI8PXy5jIutKKEn0gvgMU=; b=aX95ch9sjUJT8OsFzryyicDq6N CkNe6JUGbjUCe7UBtNFotHej386ZlqBI9PHKRaYu6PzFZkICt2wO81cAsRvJqZgvCui/VVXWI/fPg CJ8QzAwVve3iaokbyTdkbfF8KYUy0I5Jfc0UwIVTnoozIyeWSq9GlXSPI4bkoH0fHO4qogozDMSaL W/1ZJZMb4FJB+Fa6iUwBF8lKjh+Qq8gqmVVXIC/fBoOw1hPnxteDaAJQJsTDtIMeIneSc9InNpC7V /O3zlyp4zKX8YAj6MpNrD5QHaydegq7CdEJH5ITXny7XJeBsvW3UXy3UsnlhjbjR8FjNTqOznsWtU l+KMg5eA==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1sdQOE-0000000HGuh-13nD; Mon, 12 Aug 2024 08:26:54 +0000 Date: Mon, 12 Aug 2024 01:26:54 -0700 From: Christoph Hellwig To: Barry Song <21cnbao@gmail.com> Cc: akpm@linux-foundation.org, linux-mm@kvack.org, baolin.wang@linux.alibaba.com, chrisl@kernel.org, david@redhat.com, hannes@cmpxchg.org, hughd@google.com, kaleshsingh@google.com, kasong@tencent.com, linux-kernel@vger.kernel.org, mhocko@suse.com, minchan@kernel.org, nphamcs@gmail.com, ryan.roberts@arm.com, senozhatsky@chromium.org, shakeel.butt@linux.dev, shy828301@gmail.com, surenb@google.com, v-songbaohua@oppo.com, willy@infradead.org, xiang@kernel.org, ying.huang@intel.com, yosryahmed@google.com, hch@infradead.org, Chuanhua Han Subject: Re: [PATCH v6 2/2] mm: support large folios swap-in for zRAM-like devices Message-ID: References: <20240726094618.401593-1-21cnbao@gmail.com> <20240802122031.117548-1-21cnbao@gmail.com> <20240802122031.117548-3-21cnbao@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240802122031.117548-3-21cnbao@gmail.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 4289640016 X-Stat-Signature: 18rz348kuyrzuq4xgjwro41k6b7bfqzp X-Rspam-User: X-HE-Tag: 1723451223-454186 X-HE-Meta: U2FsdGVkX1+9tdqPzLfqp+pvENYbM1lo4pVYnVg+8JJSHgy/04OvomsmfbUhzt/VkfOdnYaAes0482ynT+zJzXHuLx6uIYyYICEyjMBvtTdEqksO0kwhwDImzXRRdA3TpxEfuJBDBDg511leFF8/2EK8LZZlFymdgOjLjm/L46Z33FT6URFUCpeoDNl/4I7JVk/Uq//7vhyJdm+7xY05eOg78zGKGGBO6R/PgoTrxMOs6rdCTzNc8s1frUI5pl3rFIn/snzZ+r/dQuE3vHZB1UhiA2XynB+MHNd5Nay6al+3fQdeGfaFnraNRg0gC6N09mOpiPJnStl67Q58DKE3sHg4uhuSSYFPELSWX2seqh3dSKy06L2N1xAMz/xvLnTExfxVd4UcaqzvoqbUQeuiWdn+BDQqVfy/nZI7KYxgITV5eIww1oC/W0aM6YVTVWCPdECjug3t7/sn36XFYjHc7Nug1XgoCTb23g9DmO3Lp6a91Ld1NIlaYJpCw62RuQyMpKMGutVcy6vha551WjOhd6OQLBiRKOax7NefP2T10h6YK1o7Hpx9rfhWVc/gJ0QYfmXLnnNMbSMjnMqM2GHA+kXp8og+VJgQLjjo603ZLDNk5MRaeF1Dz7SkW0SKxw1QcZPSuPmZVsAPzmQEJLhNNri4chryRcgg/cdjm2uhIfjN2+BE5QGfyu9bWeah0N8DW5PKE0d2LH0RbqBE3uHHDCyiohmz7VQKboM0qH08OwGzebITm7K1gS1V1yjrkTyyKtqOqfgPaLrYp+eVO0DwqDZGcdd8zmSkHxTvytTqv9jwsHdG35nguxkbntsCC5gFbCQDE+M2/uvB85m0lA7JM0kGsweedfu5gxDNa8SQCW74LBo+7GuNZlKVivwgkqi4HTQtp7hm0T/5Jyb9ISByGfmcRCf19oP8X72M8GS6W4BNx/kwaZ8ot7DpuB7I5GhiSACMWwzG0GwEt7rFc7A joYO6sK0 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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: The subject feels wrong. Nothing particular about zram, it is all about SWP_SYNCHRONOUS_IO, so the Subject and commit log should state that. On Sat, Aug 03, 2024 at 12:20:31AM +1200, Barry Song wrote: > From: Chuanhua Han > > Currently, we have mTHP features, but unfortunately, without support for large > folio swap-ins, once these large folios are swapped out, they are lost because > mTHP swap is a one-way process. The lack of mTHP swap-in functionality prevents Please wrap your commit logs after 73 characters to make them readable. > +/* > + * check a range of PTEs are completely swap entries with > + * contiguous swap offsets and the same SWAP_HAS_CACHE. > + * ptep must be first one in the range > + */ Please capitalize the first character of block comments, make them full sentences and use up all 80 characters. > + for (i = 1; i < nr_pages; i++) { > + /* > + * while allocating a large folio and doing swap_read_folio for the And also do not go over 80 characters for them, which renders them really hard to read. > +static struct folio *alloc_swap_folio(struct vm_fault *vmf) > +{ > + struct vm_area_struct *vma = vmf->vma; > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE Please stub out the entire function.