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 87965C48BC4 for ; Tue, 20 Feb 2024 05:02:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 46C4E6B007D; Tue, 20 Feb 2024 00:02:42 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 41CAA6B0087; Tue, 20 Feb 2024 00:02:42 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2E5066B0088; Tue, 20 Feb 2024 00:02:42 -0500 (EST) 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 1B2D06B007D for ; Tue, 20 Feb 2024 00:02:42 -0500 (EST) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id ACED01C030F for ; Tue, 20 Feb 2024 05:02:41 +0000 (UTC) X-FDA: 81810986922.24.03DADA3 Received: from mail-pj1-f52.google.com (mail-pj1-f52.google.com [209.85.216.52]) by imf25.hostedemail.com (Postfix) with ESMTP id BDC1DA000A for ; Tue, 20 Feb 2024 05:02:39 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=aZCgVRsV; dmarc=pass (policy=none) header.from=chromium.org; spf=pass (imf25.hostedemail.com: domain of senozhatsky@chromium.org designates 209.85.216.52 as permitted sender) smtp.mailfrom=senozhatsky@chromium.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1708405359; 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=i7hcAUjulo0+/qim2LMcT08gaOMiztNgOLDf1ljB3M8=; b=bSfnKGQu6pSL5Bd1zf+7uDOQux1/5xPuV+EVo7B4vL0dOZgn8zgZU9eXtrSnkUw0avsE05 1DLsrxeC3sclXlO/qafKFZjg2Mv3qsLx21sP6CCU6zv2B2l/hnFVFSgHUTdIgvI6ByxbjV cnjmZz07RPHJG5TqExbpfCPwOizqnCM= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=aZCgVRsV; dmarc=pass (policy=none) header.from=chromium.org; spf=pass (imf25.hostedemail.com: domain of senozhatsky@chromium.org designates 209.85.216.52 as permitted sender) smtp.mailfrom=senozhatsky@chromium.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1708405359; a=rsa-sha256; cv=none; b=KluslO4uy92G3YJbiK9+pSqli8GK83AB3+B5iWXuazeeqg5WJglujv04lxsh3nJWpPPzbX 4/4P6qIN9bamKvc/Pe5V3NpB5MMWXlkLjxYQ7FQ2BaAW4zl5OI9Fw4Aja1KBPn0d/2TPfp YRmiSZRONZcK4OTjNvnlXh1TzoGmpAQ= Received: by mail-pj1-f52.google.com with SMTP id 98e67ed59e1d1-2907a17fa34so2909618a91.1 for ; Mon, 19 Feb 2024 21:02:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1708405358; x=1709010158; darn=kvack.org; 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=i7hcAUjulo0+/qim2LMcT08gaOMiztNgOLDf1ljB3M8=; b=aZCgVRsVe25M4ve8U0VFzYnj3pTiBGgRCo8rw1GdOCDJMu1ALBeaHpFAAYP3fDDWaB pfRWBszBUet4dajZfwQc05zDaUEw8cNomuCJZQSqnUnMtePLm/3jbAcW7FCU4V/pvHiN d1FLzvsn/QGkNd//B8PQGx3AzX+gcFxCVU6Kk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1708405358; x=1709010158; 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=i7hcAUjulo0+/qim2LMcT08gaOMiztNgOLDf1ljB3M8=; b=bvQ+0ghHWKjZCfNJlDM/b3CMcTqBRF8IyK+pcMEqP+7U8DEsF4n3QuFXMi9U2Eoger ogsqHgQN1S2DOiB54bQDBRqvpvlj01puBNktHyXhD+iyf2cNAUH21W83i4diq4w8PSNd 6LIP37Gk7O7nZ3OZ4stz71Z0qSarU1n0JpUXuL33Hu0oo7FJWMd4FdewzHWMqsnyavE8 XCq+BZw4x2+NVbwWfh0RK39mB7cyJv9QdLbqjbEEzY7krQsW0AZj6P/SCUoBNq4Iy+je q1rymTjwW69OvzHe6xo++0v/M3MB4Dw4rhdnuR9kHzikLQrE9mdurG0WWf8CIQbEWH0j PYKA== X-Forwarded-Encrypted: i=1; AJvYcCUYiKyFwSq7VhOcIZB79pAM1bbC8KuzxmhyFN0i7qLIj7rG16rWmPIUoxjI/sSFao//rFNHkpYKwatzwGPbnja07yQ= X-Gm-Message-State: AOJu0YwEdkqBR2yeyh5AB8qMzkiPObEXJ6LJnwOe2TDj/KRZvVg70yqv YrcWvPnr6c625rnE6m+IcJhSYELfg636EW/kS1qXqmkYfCDx961RekYpRieyCw== X-Google-Smtp-Source: AGHT+IFnw8f+Iv8s0JtZeRo/Aq/frJZM4gToXTA5lqXQHkUoidmeMbJ82/S1IYyUPI8tCKvvGWgBnA== X-Received: by 2002:a17:90a:4381:b0:298:c136:2ffc with SMTP id r1-20020a17090a438100b00298c1362ffcmr10210738pjg.45.1708405358502; Mon, 19 Feb 2024 21:02:38 -0800 (PST) Received: from google.com ([2401:fa00:8f:203:8998:e92c:64ca:f09f]) by smtp.gmail.com with ESMTPSA id x18-20020a17090aca1200b0029933f5b45dsm6277027pjt.13.2024.02.19.21.02.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Feb 2024 21:02:38 -0800 (PST) Date: Tue, 20 Feb 2024 14:02:34 +0900 From: Sergey Senozhatsky To: Chengming Zhou Cc: Sergey Senozhatsky , nphamcs@gmail.com, yosryahmed@google.com, Minchan Kim , Andrew Morton , hannes@cmpxchg.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/3] mm/zsmalloc: remove migrate_write_lock_nested() Message-ID: <20240220050234.GF11472@google.com> References: <20240219-b4-szmalloc-migrate-v1-0-34cd49c6545b@bytedance.com> <20240219-b4-szmalloc-migrate-v1-2-34cd49c6545b@bytedance.com> <20240220044825.GD11472@google.com> <4f3c6c96-3bea-4369-a2de-e3c559505bba@bytedance.com> <20240220045340.GE11472@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Stat-Signature: xn3u5kiy9kaayq8s87gw6qnciet85p7j X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: BDC1DA000A X-HE-Tag: 1708405359-312799 X-HE-Meta: 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 v8CAiObi nEfJfLeDKU4dgSIPGTHrw1Rl3V/zvWU4LH6yySm4A+Ht5M02Sv78Rp2SA4sBsNXm3hxvi3bKYXRmFX7jhwgi9Y0U9pd8AbR3kg7L/AD2v/cHIExxRRq7QncH1tOWfuzQ7HaHfm1VZCbhBm98kSlGawSw1Ab+d5WUiV0rFv7vPD9IWN99QHzpWzTkh7XzLtklnV5wC0gKkhmSbOIv6cit9t1HU+DtzBOiH61w5GW9AXTg7c5ROJLPrIufseIKGHVjTewFjLLp49ajpZiOPql++9mp1qobxyffLjPty5fpI1e3rlUG0WS5z8njhQWkR3Duv7vMcy0dBvVE0lwfecAV/yM50OD6c3sBW+47tfuc9ziG+YTdVkm8PnTWimsVUfi/6IJtwuMrdkaDMipvOpVDZGMyeZoZ8YSpJBP0jy6MGzKAkkoQu/Koz6EZhkQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.181368, 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 (24/02/20 12:59), Chengming Zhou wrote: > On 2024/2/20 12:53, Sergey Senozhatsky wrote: > > On (24/02/20 12:51), Chengming Zhou wrote: > >> On 2024/2/20 12:48, Sergey Senozhatsky wrote: > >>> On (24/02/19 13:33), Chengming Zhou wrote: > >>> [..] > > > > Not really. We have, for example, the following patterns: > > > > get_zspage_mapping() > > spin_lock(&pool->lock) > > Right, this pattern is not safe actually, since we can't get stable fullness > value of zspage outside pool->lock. > > But this pattern usage is only used in free_zspage path, so should be ok. > Actually we don't use the fullness value returned from get_zspage_mapping() > in the free_zspage() path, only use the class value to get the class. > > Anyway, this pattern is confusing, I think we should clean up that? Right, looks so.