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 2381EC71153 for ; Tue, 29 Aug 2023 14:02:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 53CE58E0029; Tue, 29 Aug 2023 10:02:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4ECC28E001A; Tue, 29 Aug 2023 10:02:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3B4348E0029; Tue, 29 Aug 2023 10:02:33 -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 2C57E8E001A for ; Tue, 29 Aug 2023 10:02:33 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id E45F81201A2 for ; Tue, 29 Aug 2023 14:02:32 +0000 (UTC) X-FDA: 81177307344.19.7A22961 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf23.hostedemail.com (Postfix) with ESMTP id 403A7140021 for ; Tue, 29 Aug 2023 14:02:30 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=none; spf=pass (imf23.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1693317750; 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; bh=L7JqwbuUqjQKT7Ogli5GeGrgh4OkXOBWPziFnJxBY+I=; b=hFCY/cA5llz6rp8tt2UM/y1Wb4J+dAnOI8MMUjwPABN5eqf7zgwxeFXX583oRz6eH10EbE 4dAYv5bf2sv6wuAuHz8v8QiwgNE6ygPMg9S9U1VeAhevFYcZzEjBhIw/Bpq1zE3yVt26Uz YVSY7utOfo9OEnXlSbSfpSIWTsxOZXw= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1693317750; a=rsa-sha256; cv=none; b=SynKK2hlI6GRRAH0fy7vLgq8Ld0xA226f3L73ytXEJuaBDyzAYyLcKDiT5zdsnMozhDo4z b5aSQv8D6P5xN4TkDyCdctoONaDoVOxpzXTEE1enb5Bnr1wbbYbN4MHwS16GI4Jk/zozoO oWzhGebBgOf2I43S/hvP1mvhGB6hisw= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=none; spf=pass (imf23.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 70DFE2F4; Tue, 29 Aug 2023 07:03:08 -0700 (PDT) Received: from [10.1.27.141] (XHFQ2J9959.cambridge.arm.com [10.1.27.141]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 877453F64C; Tue, 29 Aug 2023 07:02:26 -0700 (PDT) Message-ID: <29099099-7ef2-45cb-bab7-455f58de47d1@arm.com> Date: Tue, 29 Aug 2023 15:02:22 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 4/4] mm/mmu_gather: Store and process pages in contig ranges To: Matthew Wilcox Cc: Will Deacon , "Aneesh Kumar K.V" , Andrew Morton , Nick Piggin , Peter Zijlstra , Christian Borntraeger , Sven Schnelle , Arnd Bergmann , David Hildenbrand , Yu Zhao , "Kirill A. Shutemov" , Yin Fengwei , Yang Shi , "Huang, Ying" , Zi Yan , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20230810103332.3062143-1-ryan.roberts@arm.com> <20230810103332.3062143-5-ryan.roberts@arm.com> Content-Language: en-GB From: Ryan Roberts In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 403A7140021 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: oy4fe48m1nyejgnzetjtqffo8sx51h78 X-HE-Tag: 1693317750-974865 X-HE-Meta: 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 IE/QNwl8 BMlWUvVraThfyVnHy2nrfgQofNFr1/4lB/fhrBViREOp1FnNSBU26GgwrxHbTq3RHP/xtpMu6gUpo7ojymSe6BRkOnzJ0AonsuJHPrIlvaRnZYEkzMIQXwTFZvrUTIKbLHBRKNvkudYSFVNs8kK3WT7IvQKlOznkFezeF/tZhcaWc7xF+4N6zEdDb9SlXOZ1xyjVD 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: On 25/08/2023 05:09, Matthew Wilcox wrote: > On Thu, Aug 10, 2023 at 11:33:32AM +0100, Ryan Roberts wrote: >> +void folios_put_refs(struct folio_range *folios, int nr) >> +{ >> + int i; >> + LIST_HEAD(pages_to_free); >> + struct lruvec *lruvec = NULL; >> + unsigned long flags = 0; >> + unsigned int lock_batch; >> + >> + for (i = 0; i < nr; i++) { >> + struct folio *folio = page_folio(folios[i].start); >> + int refs = folios[i].end - folios[i].start; >> + >> + /* >> + * Make sure the IRQ-safe lock-holding time does not get >> + * excessive with a continuous string of pages from the >> + * same lruvec. The lock is held only if lruvec != NULL. >> + */ >> + if (lruvec && ++lock_batch == SWAP_CLUSTER_MAX) { >> + unlock_page_lruvec_irqrestore(lruvec, flags); >> + lruvec = NULL; >> + } >> + >> + if (is_huge_zero_page(&folio->page)) >> + continue; >> + >> + if (folio_is_zone_device(folio)) { >> + if (lruvec) { >> + unlock_page_lruvec_irqrestore(lruvec, flags); >> + lruvec = NULL; >> + } >> + if (put_devmap_managed_page(&folio->page)) >> + continue; >> + if (folio_put_testzero(folio)) > > We're only putting one ref for the zone_device folios? Surely > this should be ref_sub_and_test like below? Good point. This function is originally a copy/paste of release_pages(), and I obviously missed this. In fact, looking at it again today, I think I'll factor out the vast majority into a common helper, since I'm currently duplicating a whole bunch here. In practice I think all devmap folios will be small today though? So while I agree I need to fix this, I think in practice it will currently do the right thing? > >> + free_zone_device_page(&folio->page); >> + continue; >> + } >> + >> + if (!folio_ref_sub_and_test(folio, refs)) >> + continue; >> + >> + if (folio_test_large(folio)) { >> + if (lruvec) { >> + unlock_page_lruvec_irqrestore(lruvec, flags); >> + lruvec = NULL; >> + } >> + __folio_put_large(folio); >> + continue; >> + } >> + >> + if (folio_test_lru(folio)) { >> + struct lruvec *prev_lruvec = lruvec; >> + >> + lruvec = folio_lruvec_relock_irqsave(folio, lruvec, >> + &flags); >> + if (prev_lruvec != lruvec) >> + lock_batch = 0; >> + >> + lruvec_del_folio(lruvec, folio); >> + __folio_clear_lru_flags(folio); >> + } >> + >> + /* >> + * In rare cases, when truncation or holepunching raced with >> + * munlock after VM_LOCKED was cleared, Mlocked may still be >> + * found set here. This does not indicate a problem, unless >> + * "unevictable_pgs_cleared" appears worryingly large. >> + */ >> + if (unlikely(folio_test_mlocked(folio))) { >> + __folio_clear_mlocked(folio); >> + zone_stat_sub_folio(folio, NR_MLOCK); >> + count_vm_event(UNEVICTABLE_PGCLEARED); >> + } > > You'll be glad to know I've factored out a nice little helper for that. OK, what's it called? This is just copied from release_pages() at the moment. Happy to use your helper in the refactored common helper. >