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bh=rNKm/FBXON69zfkdwg//RKhKlf2JyDi+UDBM9ckgKRg=; b=47A0euJJt653yC1Zr//T2LCZsF VxQD/qUkuk7KqkLXEAgfcALylKhcWlwO4HBPhsCKu/BcK9QPry6z8D9EwWJlvt1KSjNZ2IMYnf2Fw zW9B0BkVxuDhRN8UB35h5Hb0f3pPhvstn1MG1O+YLauv/OG5eRauTYaaUCXDjyLXp6QFpA8gLy8BQ IJ0PTCRe/EsN4o1M02BlARQWDgIlUJEe6bOTJfmHC9oepaKIgA5/vDFFXPbJqRpG3+dVhGl7iP57U 7eJp7J/v+Ix2UOwnnLO02xKpPle9MhYkuxE0cM1vxRKWv3A2zkxq0xTNT2dfHvMgZhBziM7eTN/Ee Ty+FZILQ==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1pegRG-00DJjO-00; Tue, 21 Mar 2023 18:10:26 +0000 Date: Tue, 21 Mar 2023 11:10:25 -0700 From: Luis Chamberlain To: Matthew Wilcox Cc: Yangtao Li , Alexander Viro , Christian Brauner , Andrew Morton , Kees Cook , Iurii Zaikin , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] fs/drop_caches: move drop_caches sysctls into its own file Message-ID: References: <20230321130908.6972-1-frank.li@vivo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 168B74001E X-Stat-Signature: 6n7xaaqfxi5sbiu9g1g3h8kiz1hphhiw X-HE-Tag: 1679422236-143813 X-HE-Meta: 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 OI3LnuG2 84obHbH+ed/P4KKTGvhCrfBr+VRU24BWmGVTk/SODXmoLySP4/9n8eG44VsIDC1w5+b74/BNWAW6QsVdMGTWIuNxc7A3mU82BU1YGKBCWMescKDXIZcFq2LpScAkYDop8GPlOtdFnvQa2NLDhEdZOEnvE1YSRrR6j5voevVW6czqqGZ8AJMSy3Y13ks1/G/iJe0E5amZBoyFJjLNAQRa1iGODol8yviazJx6ZoaP1wa0gMq67Te/mg5q2Ar/eOvdisCzkHQJMmhzu3KhA8LgeG8lhxFeWTVucWpfr/IEIhXN4qef3ouIa/NfDGYEm5Ggn7HaaiW6JWnOO0VoKi5mDUyfyADixrk8b1jb2fAVa5jeuzykZn1ygHUDvRQ== 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 Tue, Mar 21, 2023 at 05:19:18PM +0000, Matthew Wilcox wrote: > On Tue, Mar 21, 2023 at 09:56:03AM -0700, Luis Chamberlain wrote: > > On Tue, Mar 21, 2023 at 04:42:32PM +0000, Matthew Wilcox wrote: > > > On Tue, Mar 21, 2023 at 09:09:07PM +0800, Yangtao Li wrote: > > > > +static struct ctl_table drop_caches_table[] = { > > > > + { > > > > + .procname = "drop_caches", > > > > + .data = &sysctl_drop_caches, > > > > + .maxlen = sizeof(int), > > > > + .mode = 0200, > > > > + .proc_handler = drop_caches_sysctl_handler, > > > > + .extra1 = SYSCTL_ONE, > > > > + .extra2 = SYSCTL_FOUR, > > > > + }, > > > > + {} > > > > +}; > > > > > > Could we avoid doing this until we no longer need an entire zero entry > > > after the last one? > > > > That may be 2-3 kernel release from now. The way to use ARRAY_SIZE() > > really is to deprecate the crap APIs that allow messy directory sysctl > > structures. > > I'm OK with waiting another year to commence this cleanup. We've lived > with the giant tables for decades already. Better to get the new API > right than split the tables now, then have to touch all the places > again. We can do that sure. Luis