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 D4355C7EE31 for ; Thu, 26 Jun 2025 15:07:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 110506B009A; Thu, 26 Jun 2025 11:07:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0C16C6B009B; Thu, 26 Jun 2025 11:07:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F401E6B009C; Thu, 26 Jun 2025 11:07:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id DC7376B009A for ; Thu, 26 Jun 2025 11:07:26 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 5F97DC01B5 for ; Thu, 26 Jun 2025 15:07:26 +0000 (UTC) X-FDA: 83597880492.06.E7680A6 Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [95.215.58.178]) by imf17.hostedemail.com (Postfix) with ESMTP id CC7EB4000B for ; Thu, 26 Jun 2025 15:07:22 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=rwXJthZv; spf=pass (imf17.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.178 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1750950444; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=kBC/1zbAsFpTgrTOlWvqmN/0W6sOeRbe2I8GaEuZn+U=; b=QVPohvQKlwCE/oNOohFmJw3+9ghmBrKN3WP7K67ZHrN6RjSbwJhWM33Mxp1UKqH9rP+L+7 jHHY2lHN+hTJ7g2d4bUilh+AwUPeQSIWvyAhat+h2FOQssAGo8kDDa56izyLenx+rXA13r 5KkYEOX0WEy3jV3tOoUAcndJSaqo5b4= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=rwXJthZv; spf=pass (imf17.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.178 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1750950444; a=rsa-sha256; cv=none; b=Rg9HoWUjjP5GhPTcZvdpQNibVY9mkupdgbWVXNVETTqoCTfJ6sGrdPvTR80YewQ7YbxWlt KVSYH3szT4DoYC3CznnabokqnjKj6fQj9tqH7D1z9Uvd3wwyb17eYhLvSLqroa3jJWfkqu Y5EvMQ4/zH02oLDgBvUs+G4XW8MNwfU= Message-ID: <424599d3-9bd0-4cd5-9ad7-37cebdc765e5@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1750950438; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=kBC/1zbAsFpTgrTOlWvqmN/0W6sOeRbe2I8GaEuZn+U=; b=rwXJthZvAow/TQ7NghrfNCplJc1HKGgRLL2BT/VCLAVS9iExHzIvFe76KM5Ym+drnT9iNK I7eq87HK3WMGi/9Y+aMJIQQOZ4EVrCIDZNQKaKIUbL0aGyMz4LGpRNYOOURq7W4o4CbUDK om962XvRHAyMXkvg+foBGCsYMvV/vvI= Date: Thu, 26 Jun 2025 23:06:11 +0800 MIME-Version: 1.0 Subject: Re: [PATCH v4 3/4] mm: Support batched unmap for lazyfree large folios during reclamation Content-Language: en-US To: David Hildenbrand Cc: 21cnbao@gmail.com, akpm@linux-foundation.org, baolin.wang@linux.alibaba.com, chrisl@kernel.org, kasong@tencent.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, lorenzo.stoakes@oracle.com, ryan.roberts@arm.com, v-songbaohua@oppo.com, x86@kernel.org, ying.huang@intel.com, zhengtangquan@oppo.com, Lance Yang References: <20250626092905.31305-1-ioworker0@gmail.com> <20250626124445.77865-1-ioworker0@gmail.com> <1a55f9f3-f5b1-4761-97ba-423756c707fe@redhat.com> <6fbcf806-eb3c-4bcd-8daf-8d87fd759d2b@redhat.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: <6fbcf806-eb3c-4bcd-8daf-8d87fd759d2b@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: CC7EB4000B X-Stat-Signature: 3q37masxbq3mxhcis3ouedxjx7sfhyky X-HE-Tag: 1750950442-100081 X-HE-Meta: U2FsdGVkX1/NaKDi59+clxI2LvgFt94t27q9IjRET6KtD4vGRZjgTCuldT9e/PD39twOape53d+XjUVwCAMRgawrm78jscof+4VVsdreSYd3TsKQlL4tmX+StQtnjMOUYSeCA+M2+QVrGT7ugZ/6x/iAw1W8G7y8x/BVlzzM/pj42GDHk29SemQNBKi28Yahz++Ohme5EUrMLEkRpQUx4SiYLPIjmfdGvSuZGgL/ZOj6sfQCdB8pDJ7uSsEFpjD4OpW45GGKJHlM4kfOWzPZsxzXFi51UPFk+SKEizNdWj7azpC1glLD9qlaWA3oLE7euBKg/W06dd1Sk+lOiWBgUlrn7b0/47Ds0A7MUZDHwu6YuX6SGHKuEI6PZiXm+utfkGtzE10/sKoC5HWKSyPN0sc1g5Qb15wh4eiQDybGoCYCBoc0uUucGFS7VY7eY1OHlyjrOJuWvfesseY44gA2L5gVymKQ5fPLgSdlg87nEtZapkBINlRmSOjgcZ38zce9wlcJhLSnIBsJQiZn6Mzi63AAMbJHFXzyfN/Uh3khP3hKI6PnVzOghbG0EXoQ5bNtjLtFqZYkNAcnpjW5ByRqi5D5UUnpxZsdSHka9+EXTkLYP40EQClFGI97C67RE3TyqRG9VLJ+3t+vYpcBpBuWkWGVYMP8FTOmcGuGLP0qckg3QwPZU3ndRZhtb2lv3l4LEs+P/a5gYPISJ2fA7LXvDUCs0JpywAa0dvCWcGO1JAscZDo2XrB0+dUmV40Ka3xlF00TQCRM5mXKVez4zbQTOer49vo3ofusG00JlG6HSiztOKiWwvL7GXGKIgOkUvZO8+mpJLCJq//0iw6rPwmqEycoN/1hblB1804Gtgj+jVrKWe7Lmhl8SqKpKbmiaEL6AjO9GMulnmwTs78znyQ39lHV8gTd0YFjWCpTF2KjnK2iNPcA9FySZPc4Is7p1nhM+ZTY1TG9BpIfM7gPxQW UE0fbt68 +SQD/rHEH+31pdTit67X7uIJnY0dvuWNeE1BDzBdkol7ddrqciGwO6hvVEVTU4xmlTHDEmLQgUKIGvRaYvne1P4hUUwzMYTmHzqbUfsGeifHAFeYj1ugfP55sayeV+cEvjd9iLxMS7sPTxZdGmGXODEYbDOPzXWVdq/w47Eq9BWGix+4RYjhf6w23jsgAvsEs3Z9LwrRtgkNhYN6uhSZ9cJuFtZvhfLCr8rYTaBL1qHnc9+C90reu5slRcg== 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 2025/6/26 22:39, David Hildenbrand wrote: [...] >>>> @@ -1870,12 +1870,13 @@ static inline unsigned int >>>> folio_unmap_pte_batch(struct folio *folio, >>>>            return 1; >>>>        /* ... where we must be able to batch the whole folio. */ >>> >>> Why is that still required? :) >> >> Sorry ... I was still stuck in the "all-or-nothing" mindset ... >> >> So, IIUC, you mean we should completely remove the "max_nr < nr_pages" >> check and just let folio_pte_batch handle whatever partial batch it >> safely can. >> >>> >>>> -    if (pte_pfn(pte) != folio_pfn(folio) || max_nr != >>>> folio_nr_pages(folio)) >>>> +    if (pte_pfn(pte) != folio_pfn(folio) || max_nr < nr_pages) >>>>            return 1; >>>> -    max_nr = folio_pte_batch(folio, addr, pvmw->pte, pte, max_nr, >>>> fpb_flags, >>>> -                 NULL, NULL, NULL); >>>> -    return (max_nr != folio_nr_pages(folio)) ? 1 : max_nr; >>>> +    max_nr = folio_pte_batch(folio, addr, pvmw->pte, pte, nr_pages, >>>> +                 fpb_flags, NULL, NULL, NULL); >>>> + >>>> +    return (max_nr != nr_pages) ? 1 : max_nr; >>> >>> Why is that still required? :) >> >> Then simply return the number of PTEs that consecutively map to the >> large folio. Right? > > Yes. Any part of the large folio. Just return folio_pte_batch() ... > Ah, got it. Thanks!