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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 82462160017 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: tsr89bza7jmoz4okjftcenny9k3bikrs X-HE-Tag: 1702965506-249136 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000104, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 12/19/23 12:06 PM, Matthew Wilcox wrote: > On Tue, Dec 19, 2023 at 10:42:46AM +0800, Jingbo Xu wrote: >> } else { >> bdi->max_ratio = max_ratio; >> - bdi->max_prop_frac = (FPROP_FRAC_BASE * max_ratio) / 100; >> + bdi->max_prop_frac = div64_u64(FPROP_FRAC_BASE * max_ratio, >> + 100 * BDI_RATIO_SCALE); >> } > > Why use div64_u64 here? > > FPROP_FRAC_BASE is an unsigned long. max_ratio is an unsigned int, so > the numerator is an unsigned long. BDI_RATIO_SCALE is 10,000, so the > numerator is an unsigned int. There's no 64-bit arithmetic needed here. Yes, div64_u64() is actually not needed here. So it seems bdi->max_prop_frac = FPROP_FRAC_BASE * max_ratio / 100 / BDI_RATIO_SCALE; is adequate? -- Thanks, Jingbo