From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 11 Feb 2008 12:27:48 -0800 From: Andrew Morton Subject: Re: [PATCH 8/8] Re-enable msgmni automatic recomputing msgmni if set to negative Message-Id: <20080211122748.64e7bc36.akpm@linux-foundation.org> In-Reply-To: <20080211141816.520049000@bull.net> References: <20080211141646.948191000@bull.net> <20080211141816.520049000@bull.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nadia.Derbey@bull.net Cc: linux-kernel@vger.kernel.org, y-goto@jp.fujitsu.com, linux-mm@kvack.org, containers@lists.linux-foundation.org, matthltc@us.ibm.com, cmm@us.ibm.com List-ID: On Mon, 11 Feb 2008 15:16:54 +0100 Nadia.Derbey@bull.net wrote: > [PATCH 08/08] > > This patch is the enhancement as asked for by Yasunori: if msgmni is set to > a negative value, register it back into the ipcns notifier chain. > > A new interface has been added to the notification mechanism: > notifier_chain_cond_register() registers a notifier block only if not already > registered. With that new interface we avoid taking care of the states changes > in procfs. > > ... > > static int proc_ipc_callback_dointvec(ctl_table *table, int write, > struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos) > { > + struct ctl_table ipc_table; > size_t lenp_bef = *lenp; > int rc; > > - rc = proc_ipc_dointvec(table, write, filp, buffer, lenp, ppos); > + memcpy(&ipc_table, table, sizeof(ipc_table)); > + ipc_table.data = get_ipc(table); > + > + rc = proc_dointvec(&ipc_table, write, filp, buffer, lenp, ppos); > > if (write && !rc && lenp_bef == *lenp) > - /* > - * Tunable has successfully been changed from userland: > - * disable its automatic recomputing. > - */ > - unregister_ipcns_notifier(current->nsproxy->ipc_ns); > + tunable_set_callback(*((int *)(ipc_table.data))); > > return rc; > } > @@ -119,12 +142,14 @@ static int sysctl_ipc_registered_data(ct > rc = sysctl_ipc_data(table, name, nlen, oldval, oldlenp, newval, > newlen); > > - if (newval && newlen && rc > 0) > + if (newval && newlen && rc > 0) { > /* > - * Tunable has successfully been changed from userland: > - * disable its automatic recomputing. > + * Tunable has successfully been changed from userland > */ > - unregister_ipcns_notifier(current->nsproxy->ipc_ns); > + int *data = get_ipc(table); > + > + tunable_set_callback(*data); > + } > > return rc; > } hm, what's happening here? We take a local copy of the caller's ctl_table and then pass that into proc_dointvec(). Is that as hacky as it seems?? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org