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Thu, 10 Apr 2025 14:13:08 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id v1s6F/TR92dxdgAAD6G6ig (envelope-from ); Thu, 10 Apr 2025 14:13:08 +0000 Date: Thu, 10 Apr 2025 16:12:57 +0200 From: Oscar Salvador To: David Hildenbrand Cc: Gavin Shan , linux-mm@kvack.org, linux-kernel@vger.kernel.org, adityag@linux.ibm.com, donettom@linux.ibm.com, gregkh@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org, akpm@linux-foundation.org, shan.gavin@gmail.com Subject: Re: [PATCH] drivers/base/memory: Avoid overhead from for_each_present_section_nr() Message-ID: References: <20250410125110.1232329-1-gshan@redhat.com> <9deb3725-8991-43d1-8c3d-56523fabff28@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Action: no action X-Rspamd-Queue-Id: B33B6180006 X-Rspamd-Server: rspam05 X-Rspam-User: X-Stat-Signature: t9g5cuiw5tz41zyrcdt3wdsnd55hk57f X-HE-Tag: 1744294390-730858 X-HE-Meta: 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 aA6p2ta5 QA34u93pK5v8TMyNzJ43ZCdDgTHVMhBtSzK9XF6lf7MwlJGWYVZBSCBPm/y41Jo21GlO4MIdpnJXCOlRPydOpFVGWT0U5A3wKOte3WOfKRSYwOHBaP6UJ1XfXQ/oOVLuFtREVIKLOORNcUYIyHFec0y8hgmWsSCwJ2Pm7hPcYBPMTguSFzlDfbRjJ0hWm4N4e9Et9tZScXgwMU/xW26jxcljlHP+sAf3AjXJRq2TVTAZ/Vc9OFWAm387hK5S9gWkjv+OEitQZKhkcxtN7O35Jj3JyQaPggeE3+ejh6oxL/z3bvjiWRAStnhazjyjxacTPApAN2cDPAGOF4nVthILTl4DOPbNPqvAenX0OK0r/hofmIH7Ujbrf3dAMYL5vUfcvPOAX X-Bogosity: Ham, tests=bogofilter, spamicity=0.002754, 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 Thu, Apr 10, 2025 at 03:55:19PM +0200, Oscar Salvador wrote: > All in all, I think we are better, and the code is slightly simpler? One thing to notice is that maybe we could further improve and leap 'nr' by the number of sections_per_block, so in those scenarios where a memory-block spans multiple sections this could be faster? Just a thought, and maybe not worth it. In the end, we have payed more than once the price of trying to be too smart wrt. sections and boot tricks :-). -- Oscar Salvador SUSE Labs