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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9DCFDECAAD1 for ; Thu, 1 Sep 2022 01:22:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231754AbiIABWK (ORCPT ); Wed, 31 Aug 2022 21:22:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231441AbiIABWG (ORCPT ); Wed, 31 Aug 2022 21:22:06 -0400 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6EA69E190C for ; Wed, 31 Aug 2022 18:22:05 -0700 (PDT) Received: by mail-pj1-x1029.google.com with SMTP id j9-20020a17090a3e0900b001fd9568b117so1014350pjc.3 for ; Wed, 31 Aug 2022 18:22:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc; bh=nGbSPl6vfUxnpVaxdq8qn8cGXULdrRBFaoDPHGxfyrQ=; b=EI5j0lvZBm62JicpfiQSBi7BYb4g1q1L64BDiYbBF+l1fAE5ZYWpsfKSXW2Yfo1KDB ByFErbxVMNQRgeoxwV2ojR5jQQbHvGR2AOhyOGE86qEgyAFQsCZkJxPe6zyOJ5SR/E0H R2VDSdiJbBfwVtNA7yxUvypvmlAghteEHxRDA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=nGbSPl6vfUxnpVaxdq8qn8cGXULdrRBFaoDPHGxfyrQ=; b=0HrW3hNThwbHaVTr5iF2+HeIX2QnYfppldAGypzk5dylsEd9iTQ+aG12/IUgmgdHsB RitCNMf6bSWm25N6VzxqC3yYidbLxySglVPxShk+h+yFx0VIiJjrLKAqzS+WSt8Ep38d l5YmmFEyx1Kv/2G0WXd6Ehj9rAprq2dc6RNxsI6yV1y/yB976s/CMjwz732wMfuL5CWD H4iT+OlWFF7b8T9fnKFnqEe2DrTiSlnDyIGsfZFY2JS9ilZOzB4kryKviH7cfU306S2G eyAMeN62mzgFz7N3CQ+IJ9CluIjSu+t9OkrL7cW6iTA1f15QbuIgwqC7li/XElArjzSv 9ZoQ== X-Gm-Message-State: ACgBeo2deuSDFa6ICcYKnjsHdOYzB/7zK7B+NGrzXEKtmS7oV9+X3ru0 5aarJATAZKDKThS+V5GBUYaqhw== X-Google-Smtp-Source: AA6agR6taB/DtW1RsVuwX04HNOdPTnYauju6iD2tOkpmyqZmHPFGW+xFSLlmBl3YkGfdTCeQPF0scw== X-Received: by 2002:a17:903:25c4:b0:174:4311:bf17 with SMTP id jc4-20020a17090325c400b001744311bf17mr26602118plb.103.1661995324965; Wed, 31 Aug 2022 18:22:04 -0700 (PDT) Received: from google.com ([110.11.159.72]) by smtp.gmail.com with ESMTPSA id f17-20020a170902f39100b0016b81679c1fsm390242ple.216.2022.08.31.18.22.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 31 Aug 2022 18:22:04 -0700 (PDT) Date: Thu, 1 Sep 2022 10:21:58 +0900 From: Sergey Senozhatsky To: Alexey Romanov , Minchan Kim , Andrew Morton Cc: senozhatsky@chromium.org, ngupta@vflare.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel@sberdevices.ru Subject: Re: [PATCH v1] zsmalloc: zs_object_copy: replace email link to doc Message-ID: References: <20220815144825.39001-1-avromanov@sberdevices.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220815144825.39001-1-avromanov@sberdevices.ru> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (22/08/15 17:48), Alexey Romanov wrote: > diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c > index 99d93a48cbe0..17641bde5432 100644 > --- a/mm/zsmalloc.c > +++ b/mm/zsmalloc.c > @@ -1559,8 +1559,8 @@ static void zs_object_copy(struct size_class *class, unsigned long dst, > * Calling kunmap_atomic(d_addr) is necessary. kunmap_atomic() > * calls must occurs in reverse order of calls to kmap_atomic(). > * So, to call kunmap_atomic(s_addr) we should first call > - * kunmap_atomic(d_addr). For more details see > - * https://lore.kernel.org/linux-mm/5512421D.4000603@samsung.com/ > + * kunmap_atomic(d_addr). For more details see > + * Documentation/mm/highmem > */ > if (s_off >= PAGE_SIZE) { > kunmap_atomic(d_addr); So I'm not against this patch, but in general I don't think we document kmap_atomic/kunmap_atomic in the kernel. That's type of API that people get BUG() on and then figure out that it's a stack and pop-s should mirror push-es. We have lots of undocumented src/dst kmap-s: src = kmap_atomic(s_page); dst = kmap_atomic(d_page); do_copy_page(dst, src); kunmap_atomic(dst); kunmap_atomic(src); Like I said, I'm not against this patch, so FWIW Reviewed-by: Sergey Senozhatsky I'll let Minchan to have the final word.