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a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1678138049; bh=HAyqRJPBWOYhe525mNCiGvfIZWlnvzCu67PTvEwxrx0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z+FgstKIsqpFyF8cCJ1tHZ8P2KfFgHyOC2aeedEKRm8Pl4ga1i/uZYxLXoN6wm9mi 2K0y04/Gizq8hYjyImUPZd+nby8pCQrrj10Sz/zacUwMteS10Dt6VuZLFDzfM9TPCR yon0HovIsuKzq5uFzKjGSMoxJf95SiDv+1J3/qpAiKtT3ipsdATLwDAxFplyu85lpB 8olBSf4iMCiN3w0bWk7h/D4Go4XJDDPjHSIfEwPS5/0d8xOPOGL6GAnJ1RXPlsq+BJ 406mwdWhQxm6QuKXKZZTcA5yEzvgwU4++mtMQTvYyG6Q01/SLW0XFnktsTve+aA6+q U2J/9K+4WANMQ== From: SeongJae Park To: Kefeng Wang Cc: SeongJae Park , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, damon@lists.linux.dev Subject: Re: [PATCH v2 2/3] mm/damon/paddr: minor refactor of damon_pa_young() Date: Mon, 6 Mar 2023 21:27:27 +0000 Message-Id: <20230306212727.303846-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <202ac11d-3692-69bf-3984-627c1b9f9d38@huawei.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Queue-Id: 1CDDB40004 X-Rspamd-Server: rspam01 X-Stat-Signature: f3am38uwgf1ddjtcogsp7m1nqcrxzr1e X-HE-Tag: 1678138050-558989 X-HE-Meta: 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 +LxZrKuf J+1bqJZ53vlXSeoVDAUr2SmaHLfGfSOCBH1dr/Kcvk3b6ro7kYa9zWu3UnoddEqXW5BsAeM/cRt2wyMIWNhX0xiWVyY9tI3ex9jk+xcmJ1LbBs7UxfoXr9x9y4nIXb5kDlIf0/8dpAmKPF2WPebkt4VmIxJkyNTGkZldxdMv2TuR1whzeaM2BT4uOf9UFAw2spylSinQSSYNy24vaRDo5wdtuuYk84yF1AolIny+ym3iNGqMkyAs92etPDy93tKG4U5JSdRp8OrIPXbpjVwWhyqmY4FH5Mk54B/PzvQEG2HhDEyLthk9X+VhVBNqgcmhAJ9qM8BwPoM61kCk6pV0l7oYvcrpkr4ErnGSw6JbkhfD47MHXibw95EfVFyJZRwx1W2gUACMQL0grMibr/N59YK3qHQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi Kefeng, On Mon, 6 Mar 2023 09:56:49 +0800 Kefeng Wang wrote: > > > On 2023/3/6 9:10, Kefeng Wang wrote: > > > > > > On 2023/3/4 2:39, SeongJae Park wrote: > >> Hi Kefeng, > >> > >> On Fri, 3 Mar 2023 16:43:42 +0800 Kefeng Wang > >> wrote: > >> > >>> Omit three lines by unified folio_put(), and make code more clear. > >>> > >>> Signed-off-by: Kefeng Wang > >>> --- > >>> mm/damon/paddr.c | 11 ++++------- > >>> 1 file changed, 4 insertions(+), 7 deletions(-) > >>> > >>> diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c > >>> index 3fda00a0f786..2ef9db0189ca 100644 > >>> --- a/mm/damon/paddr.c > >>> +++ b/mm/damon/paddr.c > >>> @@ -130,24 +130,21 @@ static bool damon_pa_young(unsigned long paddr, > >>> unsigned long *folio_sz) > >>> accessed = false; > >>> else > >>> accessed = true; > >>> - folio_put(folio); > >>> goto out; > >> > >> Because you moved 'out' label to not include *folio_sz setting, > >> folio_sz will > >> not set in this case. It should be set. > > oh, it should be fixed. > >> > >>> } > >>> need_lock = !folio_test_anon(folio) || folio_test_ksm(folio); > >>> - if (need_lock && !folio_trylock(folio)) { > >>> - folio_put(folio); > >>> - return false; > >>> - } > > Hi SJ, apart from above issue, it looks that this branch need the > folio_size() setting, right? folio_sz is effectively used by caller of damon_pa_young() only if this function returns true, so this branch doesn't need to set folio_sz. Thanks, SJ > > Thanks > > >>> + if (need_lock && !folio_trylock(folio)) > >>> + goto out; > >>> rmap_walk(folio, &rwc); > >>> if (need_lock) > >>> folio_unlock(folio); > >>> - folio_put(folio); > >>> -out: > >>> *folio_sz = folio_size(folio); > >>> +out: > >>> + folio_put(folio); > >> > >> Before this change, folio_size() is called after folio_put(). > >> Shouldn't it be > >> called before folio_put()? If so, could we make a separate fix for > >> that first, > >> and then make this change on top of it, so that it can be easily > >> applied to > >> relevant stable kernels? > >> > > Yes， I could separate it, after folio_put(), the folio could be > > re-allocated and the folio_size calculation is not right. > >> > >> Thanks, > >> SJ > >> > >>> return accessed; > >>> } > >>> -- > >>> 2.35.3 > >>> > >>> >