From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-187.mta1.migadu.com (out-187.mta1.migadu.com [95.215.58.187]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48FAA4A06 for ; Thu, 9 Oct 2025 01:49:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.187 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759974569; cv=none; b=YLZhhnXmVsWUDBTVPSHJTvDU2U8cP+V6XTidaqBGq28+e4KTDD0M4pX7xi2lCoXyXs0vdk3KL3gBSS1MDPuDbZmqVjFi2toU58+aP940oEa0oN9HQ7ajPLvTgkAyYAdvS96pkAd/8Q9S3/G39IIutSrxX9AqT33JMYT57Kfcr88= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759974569; c=relaxed/simple; bh=lDCRAYq2GAvTSXdImxsuJg6Oxwc90jpMIyIeWEWwW1c=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ZrUzyOxPt54Qv275Eqh4gjv2RLHW7TXNgoRNARMu1Z3a29coS2OZicGhPIWBlUhWqPZI/szDkz0YZZYUUHGYGA4YW1qk3IZFvzdFumyeztX7y3HhDck9I3GhVxmavmBYKaXiWB8Af95BVT1N4JXqUfAUF5uIWxQmwRXt8NTVPJ4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=kOEckLtO; arc=none smtp.client-ip=95.215.58.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="kOEckLtO" Message-ID: <2ddaaf80-f16d-44be-9032-974f7e501e36@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1759974557; h=from:from: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=Gmbfo1v3pnUVofferszWtiV8RrDISxuLm2FSoyEqKmM=; b=kOEckLtOeUsZQWf1SUasgVpDk7DgTsgPid27oYpunbvpT54dOsfvmrNhbfM4b9yPwfFKf2 ffL0R1SkMSQ1DAezJ60yzZiDpJ210td/RTCNjeNq0c1t/jnxRv+uuGzrGqOGlgDOjizX1H ptlJVp+AMz3Oq+SkjxsEDD0F2sPWByA= Date: Thu, 9 Oct 2025 09:49:01 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH mm-new v3 3/3] mm/khugepaged: merge PTE scanning logic into a new helper Content-Language: en-US To: Andrew Morton Cc: david@redhat.com, lorenzo.stoakes@oracle.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, ioworker0@gmail.com, richard.weiyang@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20251008043748.45554-1-lance.yang@linux.dev> <20251008043748.45554-4-lance.yang@linux.dev> <20251008180744.008424134fbc29e9616899ad@linux-foundation.org> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: <20251008180744.008424134fbc29e9616899ad@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 2025/10/9 09:07, Andrew Morton wrote: > On Wed, 8 Oct 2025 12:37:48 +0800 Lance Yang wrote: > >> + if (!cc->is_khugepaged || >> + *unmapped <= khugepaged_max_ptes_swap) { >> + /* >> + * Always be strict with uffd-wp enabled swap >> + * entries. Please see comment below for >> + * pte_uffd_wp(). >> + */ >> + if (pte_swp_uffd_wp(pte)) { >> + *scan_result = SCAN_PTE_UFFD_WP; >> + return PTE_CHECK_FAIL; >> + } >> + return PTE_CHECK_CONTINUE; >> + } else { >> + *scan_result = SCAN_EXCEED_SWAP_PTE; >> + count_vm_event(THP_SCAN_EXCEED_SWAP_PTE); >> + return PTE_CHECK_FAIL; >> + } > > I'm inclined to agree with checkpatch here. Thanks! > > WARNING: else is not generally useful after a break or return > #81: FILE: mm/khugepaged.c:574: > + return PTE_CHECK_CONTINUE; > + } else { > > did you see this and disagree or did you forget to run checkpatch? Yes, I saw the warning. I kept the original style because this is just a code move ... > > --- a/mm/khugepaged.c~mm-khugepaged-merge-pte-scanning-logic-into-a-new-helper-checkpatch-fixes > +++ a/mm/khugepaged.c > @@ -571,11 +571,10 @@ static inline int thp_collapse_check_pte > (!cc->is_khugepaged || > *none_or_zero <= khugepaged_max_ptes_none)) { > return PTE_CHECK_CONTINUE; > - } else { > - *scan_result = SCAN_EXCEED_NONE_PTE; > - count_vm_event(THP_SCAN_EXCEED_NONE_PTE); > - return PTE_CHECK_FAIL; > } > + *scan_result = SCAN_EXCEED_NONE_PTE; > + count_vm_event(THP_SCAN_EXCEED_NONE_PTE); > + return PTE_CHECK_FAIL; > } else if (!pte_present(pte)) { > if (!unmapped) { > *scan_result = SCAN_PTE_NON_PRESENT; > @@ -600,11 +599,10 @@ static inline int thp_collapse_check_pte > return PTE_CHECK_FAIL; > } > return PTE_CHECK_CONTINUE; > - } else { > - *scan_result = SCAN_EXCEED_SWAP_PTE; > - count_vm_event(THP_SCAN_EXCEED_SWAP_PTE); > - return PTE_CHECK_FAIL; > } > + *scan_result = SCAN_EXCEED_SWAP_PTE; > + count_vm_event(THP_SCAN_EXCEED_SWAP_PTE); > + return PTE_CHECK_FAIL; > } else if (pte_uffd_wp(pte)) { > /* > * Don't collapse the page if any of the small PTEs are > _ >