From nobody Tue Jul 13 11:03:16 2021 X-Original-To: freebsd-hackers@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 30A6C8D29F3 for ; Tue, 13 Jul 2021 11:03:24 +0000 (UTC) (envelope-from khng300@gmail.com) Received: from mail-pf1-x432.google.com (mail-pf1-x432.google.com [IPv6:2607:f8b0:4864:20::432]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4GPHmq2bYFz4VHL; Tue, 13 Jul 2021 11:03:23 +0000 (UTC) (envelope-from khng300@gmail.com) Received: by mail-pf1-x432.google.com with SMTP id 21so19236496pfp.3; Tue, 13 Jul 2021 04:03:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=MpKMoDTJMx3QXDZCa1QedrM/ud6TJ+koGCzjDgF4tsg=; b=q1ANmkX1Hn27SvR5HrXwNv9IXL9xtpqCDoBK4/1Uk8WudLqCbtyrbK3vu3cRPVeUJn HGT7hChlMEvQUu2VwZRLSaORgcckI2pRAntFbdMBVsM0oq2BKRV0mPY8qbOCxtZXD9Wm /+6FIozCcI4Hy630WVtXT+ggTdFUEVYH2CtNkWJI7DZEb7JAUPy2DmKowGIM55xiqpR2 TLAf09gej+b+54jWJfi/cit4F5xBFrcLw1UhO4171oVYehdGZ5gs0WWSsmv/PB9iG7ut JhgxLx0X216jgBwy5Xmw61c0VUuhzU9xCBMZd+PNmHV6uFglgfAFfmVtcaYhMWvzBaiv kdNg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=MpKMoDTJMx3QXDZCa1QedrM/ud6TJ+koGCzjDgF4tsg=; b=EzcGYe8ShvOF5fKjJ5+RHPUKKTcn+Dcgki/8RKkEoHdQiCI/n+CKl1NPHpRFj16OIb aeTPRoMHj1poM0MtwbAKXggR6T/fWCDsscJv8P8o7nsn08XXbeHxVWo4qSA/affSLexN Cqp6DikxCFVIiaAyHsupYgoyoANnAmW37KBgrTxTv56QDGDT2S6u3YbD2xTiAQZez5Ti Jls15p6FKkMw1LkEohsvb1rTSDn/Q40kMfF1IpP1dSoShHM8WIG8/3fyAXmiR2WrgbsB NO7/Yw2KsATsB32sfXHjC+wkBOkrmBoNoHbWrvbp4tObnr75JJUghIPjJGd0SA+ZtnrL gnJg== X-Gm-Message-State: AOAM532BLGUxSf8zuPtCOy4aS0u99y3SD6UTmYWIi4SvYUB0qrJ3945P tPpczQAW4eGnswWPKcM2fWw= X-Google-Smtp-Source: ABdhPJyce+KWpOH2L8HGwWL4G3UNM1jArmrwC6qkWPps3iIY6DGJ/qdciSGB/0N/BHH0t5cfdPwu/Q== X-Received: by 2002:a63:7d15:: with SMTP id y21mr3769610pgc.352.1626174201764; Tue, 13 Jul 2021 04:03:21 -0700 (PDT) Received: from dac1f024b.dhcp.in.dimsumlabs.com ([2001:470:fbdc:6066:38d2:30c7:296f:69c5]) by smtp.gmail.com with ESMTPSA id q3sm20246342pfb.184.2021.07.13.04.03.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 13 Jul 2021 04:03:20 -0700 (PDT) Subject: Re: madvise(MADV_FREE) doesn't work in some cases? To: Vitaliy Gusev Cc: freebsd-hackers@freebsd.org, gljennjohn@gmail.com, Mark Johnston , Peter Grehan , Konstantin Belousov References: <20210703065420.6dbafb5f@ernst.home> <2390FA9B-319E-45D4-BEA7-10878E43AD4B@gmail.com> <2A7A1E60-766D-427B-8288-E92B4090022E@gmail.com> From: Ka Ho Ng Message-ID: <4cab2b26-e9cb-6ca7-fbd1-90160f07bf61@gmail.com> Date: Tue, 13 Jul 2021 19:03:16 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 List-Id: Technical discussions relating to FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-hackers List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-hackers@freebsd.org MIME-Version: 1.0 In-Reply-To: <2A7A1E60-766D-427B-8288-E92B4090022E@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4GPHmq2bYFz4VHL X-Spamd-Bar: + Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=q1ANmkX1; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of khng300@gmail.com designates 2607:f8b0:4864:20::432 as permitted sender) smtp.mailfrom=khng300@gmail.com X-Spamd-Result: default: False [1.25 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_FROM(0.00)[gmail.com]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36]; RCPT_COUNT_FIVE(0.00)[6]; RCVD_COUNT_THREE(0.00)[3]; DKIM_TRACE(0.00)[gmail.com:+]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; FREEMAIL_TO(0.00)[gmail.com]; FROM_EQ_ENVFROM(0.00)[]; SUBJECT_ENDS_QUESTION(1.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; MID_RHS_MATCH_FROM(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com:dkim]; ARC_NA(0.00)[]; RBL_DBL_DONT_QUERY_IPS(0.00)[2607:f8b0:4864:20::432:from]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; FROM_HAS_DN(0.00)[]; NEURAL_SPAM_SHORT(0.99)[0.995]; NEURAL_HAM_LONG(-0.25)[-0.246]; TAGGED_RCPT(0.00)[]; MIME_GOOD(-0.10)[text/plain]; SPAMHAUS_ZRD(0.00)[2607:f8b0:4864:20::432:from:127.0.2.255]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[2607:f8b0:4864:20::432:from]; FREEMAIL_CC(0.00)[freebsd.org,gmail.com]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-hackers]; SUSPICIOUS_RECIPS(1.50)[] X-Spam: Yes X-ThisMailContainsUnwantedMimeParts: N On 2021/7/6 3:47 AM, Vitaliy Gusev wrote: >> On 5 Jul 2021, at 21:54, Konstantin Belousov wrote: >> >> On Mon, Jul 05, 2021 at 07:32:00PM +0300, Vitaliy Gusev wrote: >> >> DONTNEED does not allow system to free pages at all. It means that pages >> are less useful and can be paged out with higher priority. >> > > That caused behaviour that memory is not freed! > > Is there a reason why FreeBSD behaviour for MADV_DONTNEED is different than in Linux and illumos ? Why it needs swap and cannot be easily dropped ? > Illumos has a similar behavior as FreeBSD in the way that it does not destroy content of the underlying object. The operation you described in Illumos is MAP_PURGE which is intended to be a bug-to-bug compatible interface. See: https://github.com/illumos/illumos-gate/commit/8905f42caceb9f470ffaa19e5f6c9fb6184d12c0 for full context. Ka Ho