From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-111.freemail.mail.aliyun.com (out30-111.freemail.mail.aliyun.com [115.124.30.111]) (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 D2E097B for ; Thu, 16 Feb 2023 02:04:35 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R211e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045170;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=18;SR=0;TI=SMTPD_---0VbmFO5J_1676513068; Received: from 30.97.48.85(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VbmFO5J_1676513068) by smtp.aliyun-inc.com; Thu, 16 Feb 2023 10:04:29 +0800 Message-ID: Date: Thu, 16 Feb 2023 10:04:29 +0800 Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.7.2 Subject: Re: [PATCH v3 3/4] mm: hugetlb: change to return bool for isolate_hugetlb() To: SeongJae Park Cc: akpm@linux-foundation.org, torvalds@linux-foundation.org, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeelb@google.com, muchun.song@linux.dev, naoya.horiguchi@nec.com, linmiaohe@huawei.com, david@redhat.com, osalvador@suse.de, mike.kravetz@oracle.com, willy@infradead.org, damon@lists.linux.dev, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20230215202548.92462-1-sj@kernel.org> From: Baolin Wang In-Reply-To: <20230215202548.92462-1-sj@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2/16/2023 4:25 AM, SeongJae Park wrote: > On Wed, 15 Feb 2023 18:39:36 +0800 Baolin Wang wrote: > >> Now the isolate_hugetlb() only returns 0 or -EBUSY, and most users did not >> care about the negative value, thus we can convert the isolate_hugetlb() >> to return a boolean value to make code more clear when checking the >> hugetlb isolation state. Moreover converts 2 users which will consider >> the negative value returned by isolate_hugetlb(). >> >> No functional changes intended. >> >> Signed-off-by: Baolin Wang >> Acked-by: David Hildenbrand >> --- > [...] >> include/linux/hugetlb.h | 6 +++--- >> mm/hugetlb.c | 13 ++++++++----- >> mm/memory-failure.c | 2 +- >> mm/mempolicy.c | 2 +- >> mm/migrate.c | 7 +++---- >> 5 files changed, 16 insertions(+), 14 deletions(-) >> > [...] >> diff --git a/mm/hugetlb.c b/mm/hugetlb.c >> index 3a01a9dbf445..16513cd23d5d 100644 >> --- a/mm/hugetlb.c >> +++ b/mm/hugetlb.c >> @@ -2925,13 +2925,16 @@ static int alloc_and_dissolve_hugetlb_folio(struct hstate *h, >> */ >> goto free_new; >> } else if (folio_ref_count(old_folio)) { >> + bool isolated; >> + >> /* >> * Someone has grabbed the folio, try to isolate it here. >> * Fail with -EBUSY if not possible. >> */ >> spin_unlock_irq(&hugetlb_lock); >> - ret = isolate_hugetlb(old_folio, list); >> + isolated = isolate_hugetlb(old_folio, list); >> spin_lock_irq(&hugetlb_lock); >> + ret = isolated ? 0 : -EBUSY; >> goto free_new; > > Nit. I'd personally prefer to set 'ret' before entering this critical section > to keep the section short, but this would be just a mean comment that wouldn't > worth request respin. Yes, good catch. And I see Andrew has helped to do this (Thanks Andrew). Thanks for reviewing.