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Mon, 5 Sep 2022 12:02:09 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id aI1dM0HlFWNodQAAMHmgww (envelope-from ); Mon, 05 Sep 2022 12:02:09 +0000 Date: Mon, 5 Sep 2022 14:02:09 +0200 From: Michal Hocko To: Ammar Faizi Cc: Oscar Salvador , Andrew Morton , Linux Kernel Mailing List , Linux Memory Management Mailing List , Vlastimil Babka , Eric Dumazet , Waiman Long , Suren Baghdasaryan , Marco Elver , Andrey Konovalov , Alexander Potapenko Subject: Re: [PATCH v2 3/3] mm,page_owner: Filter out stacks by a threshold counter Message-ID: References: <20220905031012.4450-1-osalvador@suse.de> <20220905031012.4450-4-osalvador@suse.de> <573c4049045a5ff342ff9998c69dfae7-ammarfaizi2@gnuweeb.org> <20220905115459.567583-1-ammarfaizi2@gnuweeb.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220905115459.567583-1-ammarfaizi2@gnuweeb.org> ARC-Message-Signature: i=1; a=rsa-sha256; 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dkim=pass header.d=suse.com header.s=susede1 header.b=oQWxyKzz; spf=pass (imf08.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com X-Rspamd-Server: rspam04 X-HE-Tag: 1662379331-568970 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 Mon 05-09-22 18:54:59, Ammar Faizi wrote: > On Mon, 5 Sep 2022 13:31:02 +0200, Michal Hocko wrote: [...] > > > static ssize_t write_page_owner_threshold(struct file *file, const char __user *buf, > > > size_t count, loff_t *pos) > > > { > > > char kbuf[21]; > > > int ret; > > > > > > count = min_t(size_t, count, sizeof(kbuf)); > > > if (copy_from_user(kbuf, buf, count)) > > > return -EFAULT; > > > > > > kbuf[count - 1] = '\0'; > > > ret = kstrtoul(kbuf, 10, &threshold); > > > return ret ? ret : count; > > > } > > > > Isn't there a proc_dointvec counterpart for debugfs? > > Ah, well. If that's much simpler, we should go with that. I am not > familiar proc_dointvec() interface, so I couldn't say about it. Just to clarify. proc_dointvec is rather specific to proc/sysctl interface. I was too lazy to look whether debugfs has something similar available. Maybe writing to debugfs is not all that common but I would expect a shared code to write a simple value would be there. -- Michal Hocko SUSE Labs