From mboxrd@z Thu Jan 1 00:00:00 1970 From: SeongJae Park Subject: Re: [PATCH v2 2/4] mm: change to return bool for isolate_lru_page() Date: Tue, 14 Feb 2023 19:32:04 +0000 Message-ID: <20230214193204.72057-1-sj@kernel.org> References: <3635a17b9a0cf4be011a886415bf620b1c682ff6.1676382188.git.baolin.wang@linux.alibaba.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1676403127; bh=Fcfd+XUY443lS17mBcRjKXrbkxgWMqAwxcoIbwYGHKc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I9qpkspERTRIi+Leb8IhtQMgifKx4zfEwJxHOVJyt0mvyeXuGqF5zEaCuALu2Sm/s 6PdXI5r0SCDKJvgD75s0aquFCymiUnbsITRT49SqpDKcQnGibnGrbGKo80N3Sl+wCo sYy1fYk8PjHZueGkaf5ZcOZWdsNxaQNfj1dTlueCAHXFRsEE4/KMF7cfRZHOiCeZvJ sAXLvzwg20UnL2ghQeeOJ1WFX6hfcNZVGtA7XL8GetYTT7Z5UXs+MLRBALbMFAkX7O YdnuV3q3KDAsNBLIH4B/hD/NhiZXbp4rf5IqRTmvJPcgPEo+DHB1Sl+BJWzBMYF/hm t4YH+RsjZnhtA== In-Reply-To: <3635a17b9a0cf4be011a886415bf620b1c682ff6.1676382188.git.baolin.wang@linux.alibaba.com> List-ID: Content-Type: text/plain; charset="us-ascii" To: Baolin Wang Cc: akpm@linux-foundation.org, torvalds@linux-foundation.org, sj@kernel.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 On Tue, 14 Feb 2023 21:59:30 +0800 Baolin Wang wrote: > The isolate_lru_page() can only return 0 or -EBUSY, and most users did > not care about the negative error of isolate_lru_page(), except one user > in add_page_for_migration(). So we can convert the isolate_lru_page() to > return a boolean value, which can help to make the code more clear when > checking the return value of isolate_lru_page(). > > Also convert all users' logic of checking the isolation state. > > No functional changes intended. > > Signed-off-by: Baolin Wang > --- > mm/folio-compat.c | 12 +++--------- > mm/internal.h | 2 +- > mm/khugepaged.c | 2 +- > mm/memcontrol.c | 4 ++-- > mm/memory-failure.c | 4 ++-- > mm/memory_hotplug.c | 2 +- > mm/migrate.c | 9 ++++++--- > mm/migrate_device.c | 2 +- > 8 files changed, 17 insertions(+), 20 deletions(-) > [...] > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index a1e8c3e9ab08..17ed80707518 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1668,7 +1668,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) > * LRU and non-lru movable pages. > */ > if (PageLRU(page)) > - ret = isolate_lru_page(page); > + ret = !isolate_lru_page(page); This may change return value of this function. That is, this function will return 1 instead of -EBUSY after this change. It's not a real issue as no caller of this function takes care of the return value, though. Thanks, SJ > else > ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); > if (!ret) { /* Success */ [...]