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 573C5C77B70 for ; Mon, 17 Apr 2023 11:24:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D37228E0002; Mon, 17 Apr 2023 07:24:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CE78C8E0001; Mon, 17 Apr 2023 07:24:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BAEE48E0002; Mon, 17 Apr 2023 07:24:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id A73C58E0001 for ; Mon, 17 Apr 2023 07:24:29 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 617A5A05BE for ; Mon, 17 Apr 2023 11:24:29 +0000 (UTC) X-FDA: 80690649858.05.8AEFC8E Received: from mail-pj1-f45.google.com (mail-pj1-f45.google.com [209.85.216.45]) by imf02.hostedemail.com (Postfix) with ESMTP id 6129980010 for ; Mon, 17 Apr 2023 11:24:27 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=KbNyF8OB; spf=pass (imf02.hostedemail.com: domain of senozhatsky@chromium.org designates 209.85.216.45 as permitted sender) smtp.mailfrom=senozhatsky@chromium.org; dmarc=pass (policy=none) header.from=chromium.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1681730667; 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=7LkCrILb9IuvbZSWvzfLhM66GWJHFdrMr5qCX1S/DkU=; b=m6RlD9PHnYcxA2JYp2u4sdG1TzWgAG8IdEcULJrH2U1MiUD24MrJ5nPrhpBxrwe6MWKiF6 PpYr11Dgnzeq1UB7EYTEJdYDd66dsB8yHCZDqKdYYd+bygtGhLZ8e9JiU15LdXAm/cL9SP QbXDbyr5DLy9dAW8spbtwn1xu/GnFVE= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=KbNyF8OB; spf=pass (imf02.hostedemail.com: domain of senozhatsky@chromium.org designates 209.85.216.45 as permitted sender) smtp.mailfrom=senozhatsky@chromium.org; dmarc=pass (policy=none) header.from=chromium.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1681730667; a=rsa-sha256; cv=none; b=06HEZV9PPl55MrvH/71DnCvhe//cCmxK3Avfc6ecNcBGSi6C2X+0kfNJvBIxugMQRZFaDY C+bDl19tiFPWsLSG3xtw63WoU69cIAvWwYnleYoNqJ9HVuPHKYSCSiNElfwEXev8ojNHBK fYOC9dHIlP3gHjIM2PZhQQFstW68rt0= Received: by mail-pj1-f45.google.com with SMTP id s23-20020a17090aba1700b00247a8f0dd50so1221753pjr.1 for ; Mon, 17 Apr 2023 04:24:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1681730666; x=1684322666; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=7LkCrILb9IuvbZSWvzfLhM66GWJHFdrMr5qCX1S/DkU=; b=KbNyF8OBDiZXi97ZYaJA3QSSRzMsa69uKIMSClYQLH6b2Rr0cJ8pwnj2pxQjcxY4x9 M+UmQ4Fe0QgmEixYvr4iJk85QxnXlY98AysCnXpD9iJGhMBJMaijD+5kQtlsMUJkuSMt RoybIcdHz2bg0TbSJH5AGv6Rj7DTOs+TGzjN4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681730666; x=1684322666; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=7LkCrILb9IuvbZSWvzfLhM66GWJHFdrMr5qCX1S/DkU=; b=AQnK2qpPCFwQ23OF1z8UUB8M73uwQ18ZK3xQsjYYxjeXqACP06+/uv94CimCWPMESo FjhvXrHiVxrUR4SiTFkr0vEPS1Uefc8ClOLwP705MDTKAEDylvZTcEqP4AM+Tilg834l IZ8nGrhcG2Pj5EMzbvuCTy9FiQcnB72YuaAU86dD/w2jITmAHl9UghQVtLuNig6skp3I xsy6I334U2b8V5cyDMi1pSP/l48BXeljgEa5Eq3vwGVHhjS6dUmZ8Ckxm8MMfmiSOj7a Rr3l2MzTukNzBfdY5MO0wMB+iqalADq0dpQSse7bEM9qx6j+PaLKp/CWlP5DTtZwPCgU okUw== X-Gm-Message-State: AAQBX9feKI+LD2OKyCC/CCVMBm4frTBajzLjK49mSkFPE3k0zZdqtLpc bPYOGvHEvM7jCqchqWGfUEKH3g== X-Google-Smtp-Source: AKy350YAx4Y+1l34FPHHHgsaRaE74K1JFkgBVWI188vcNGdM6psUQGX2v6zAr/nFWr/Z2VElHDtixg== X-Received: by 2002:a05:6a20:7aaf:b0:c6:bd82:ea2d with SMTP id u47-20020a056a207aaf00b000c6bd82ea2dmr14773435pzh.2.1681730666125; Mon, 17 Apr 2023 04:24:26 -0700 (PDT) Received: from google.com (KD124209188001.ppp-bb.dion.ne.jp. [124.209.188.1]) by smtp.gmail.com with ESMTPSA id 142-20020a630494000000b00513955cc174sm6960590pge.47.2023.04.17.04.24.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Apr 2023 04:24:25 -0700 (PDT) Date: Mon, 17 Apr 2023 20:24:21 +0900 From: Sergey Senozhatsky To: Yosry Ahmed Cc: Sergey Senozhatsky , Yu Zhao , Minchan Kim , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCHv4 0/4] zsmalloc: fine-grained fullness and new compaction algorithm Message-ID: <20230417112421.GO25053@google.com> References: <20230304034835.2082479-1-senozhatsky@chromium.org> <20230416151853.GK25053@google.com> <20230417024446.GL25053@google.com> <20230417035232.GM25053@google.com> <20230417111243.GN25053@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 6129980010 X-Stat-Signature: o5swe85qm4ruo8ur4h1mcm7ta7qjcjo7 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1681730667-343035 X-HE-Meta: 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 apa7yKzR 6joI37evcYxVsHpFM/hoL81+cuFHe9G0BxxLheAwbcO3D5ajTMRlvADmSMSu89TuJdMHrqXgNDdRK8zFOTyLEjsfFFeidjWxBmaYFbKN2Kzqo6tV7ZrgzN7YDd948uwCNfXvCYkY8AAJ8i7e/gDr3D9retjNhFIO7fTCfJZ+deHtG5oofcTSuiT9sW7k5foktlxYEbn+Q47MX2nW2bmz25fDr+DLG0jOW9+oO1TIBPH31HLBe0n8qt2Eqy0wYdRp/ZLDMNakfjcA2JKol2AL+pi9ad6wXVpkhqt6Tx7HR54RUj6PdOqzgVT/koEQk4WPq182DV+bjlxhWHsZIz/az7aaw7KqpSb4KXY2Ak9zarXhfA24dr9cIzg+jnuCkFIxCAqNRFJDgkXM75xGOAeCZtrJ0ctCRkGlhns2r X-Bogosity: Ham, tests=bogofilter, spamicity=0.001375, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On (23/04/17 04:16), Yosry Ahmed wrote: > > That's a good question to which I don't have an answer. We can list_add() > > the same zspage twice, unlocking the pool after first list_add() so that > > another process (including another zs_compact()) can do something to that > > zspage. The answer is somewhere between these lines, I guess. > > But the first list_add() is (in this case) the correct add, so we > expect other processes to be able to access the zspage after the first > list_add() anyway, right? Correct. Compaction also can unlock pool->lock and schedule() so that another process can access the source zspage, when compaction gets scheduled it can attempt putback/unlock the same zspage one more time (the zspage may not even exist at this point, I assume).