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b=cLZAT9s/4N6yBnQlsvKopCnL7ulX+4z0p8pH/yEGkOfPF7iqzGCYYJokZa3qR1pup nEsz2gGLNTWvMxLKPQC9uMF0Lcch/uTkeuGzfqfYxiV8snTBoIthW0uIZDS3qrm2nI c4i5fy3Y/tWT+0Sc1m254hXw3N1suzwa2k+ETC0FZ1iwwR9UEHyVN6vJffrbaAW6/V C2ACzK+zKD+62atm7qzQZVzbD7WhGMOLyfO7CrR+8x86rNCm82lD++1isx6cQKnM2/ YB2ZEt8w3lBahnyuMmCohlLy4zqsGVX5Q6AoX/ibOojKyiqMZN0sBhXYCX+4YUNTQ3 Y9dTbzG4UpcyQ== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, acsjakub@amazon.de Subject: Re: [PATCH 0/5] avoid divide-by-zero due to max_nr_accesses overflow Date: Fri, 20 Oct 2023 18:02:42 +0000 Message-Id: <20231020180242.64276-1-sj@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231020103036.027282d16aaf56498230cc12@linux-foundation.org> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 36E5DC0009 X-Stat-Signature: gh4xt68diposkf35ihc3ionhj1kgauwn X-HE-Tag: 1697824965-387012 X-HE-Meta: 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 w/hEd9Fc APm1NHujNQ4CPDXL+c12lwrwQdyd4DzW891dFDgHY6C7ilsk8nxlfdy/CEGxMzMga6txE+8kOUbeBJ9IsX0bVIIMA5PkXWoONVvuWQYQ/v6I3YObGtYfPEeantVvVCOMnoAg7X+h9Of+bdEwcOOXBrnNkWLulwpLwlXhSVne97UKkDkgOxLoJSY63Tn0wUHI0m+PrdqlJ2bGhZPodDI4SAOeR4BGSOTqBVNnHAmlKGyT7Dj+K4vIwfqjOfkBUMyLJ55e6ELs6y6NbskgWD7dCVN+7xHoJoWeetLV2PzX6vXgBtwbQrt0s27+C/x1pVBD72tJrnzLKKTaUbdkOLlaBzKqruw== 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: On Fri, 20 Oct 2023 10:30:36 -0700 Andrew Morton wrote: > On Fri, 20 Oct 2023 17:19:01 +0000 SeongJae Park wrote: > > > On Thu, 19 Oct 2023 19:49:19 +0000 SeongJae Park wrote: > > > > > The maximum nr_accesses of given DAMON context can be calculated by > > > dividing the aggregation interval by the sampling interval. Some logics > > > in DAMON uses the maximum nr_accesses as a divisor. Hence, the value > > > shouldn't be zero. Such case is avoided since DAMON avoids setting the > > > agregation interval as samller than the sampling interval. However, > > > since nr_accesses is unsigned int while the intervals are unsigned long, > > > the maximum nr_accesses could be zero while casting. > > > > Actually, the issue was reported by Jakub, and I didn't add 'Reported-by:' tags > > for him. I sure Andrew could add that on his own, but I want to minimize > > Andrew's load, so will send v2 of this patchset. Andrew, please let me know if > > that doesn't help but only increasing your load. > > Editing the changelogs is far quicker than updating a patch series ;) > > btw, it's now conventional to add a link to the reporter's report. The > new "Closes:" tag, immediately after the Reported-by:. But it's not a > big deal. Surely it is. And in this case, the report was made privately, so no available link. I should have mentioned this early, sorry. Anyway, thank you for your help, Andrew :) Thanks, SJ