Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755195AbXKWHjB (ORCPT ); Fri, 23 Nov 2007 02:39:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751551AbXKWHiy (ORCPT ); Fri, 23 Nov 2007 02:38:54 -0500 Received: from sacred.ru ([62.205.161.221]:54992 "EHLO sacred.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751506AbXKWHix (ORCPT ); Fri, 23 Nov 2007 02:38:53 -0500 Message-ID: <47468347.5090303@openvz.org> Date: Fri, 23 Nov 2007 10:37:43 +0300 From: Pavel Emelyanov User-Agent: Thunderbird 2.0.0.9 (X11/20071031) MIME-Version: 1.0 To: Cedric Le Goater , Pierre Peiffer CC: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, containers@lists.osdl.org Subject: Re: [PATCH 2.6.24-rc3-mm1] IPC: make struct ipc_ids static in ipc_namespace References: <20071122155448.3193c856.pierre.peiffer@bull.net> <474680B5.7020104@fr.ibm.com> In-Reply-To: <474680B5.7020104@fr.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-3.0 (sacred.ru [62.205.161.221]); Fri, 23 Nov 2007 10:37:50 +0300 (MSK) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 12173 Lines: 410 Cedric Le Goater wrote: > Pierre Peiffer wrote: >> Each ipc_namespace contains a table of 3 pointers to struct ipc_ids (3 for >> msg, sem and shm, structure used to store all ipcs) >> These 'struct ipc_ids' are dynamically allocated for each icp_namespace as >> the ipc_namespace itself (for the init namespace, they are initialized with >> pointers to static variables instead) >> >> It is so for historical reason: in fact, before the use of idr to store the >> ipcs, the ipcs were stored in tables of variable length, depending of the >> maximum number of ipc allowed. >> Now, these 'struct ipc_ids' have a fixed size. As they are allocated in any >> cases for each new ipc_namespace, there is no gain of memory in having them >> allocated separately of the struct ipc_namespace. >> >> This patch proposes to make this table static in the struct ipc_namespace. >> Thus, we can allocate all in once and get rid of all the code needed to >> allocate and free these ipc_ids separately. > > It looks safe and saves quite a lot of line. > > Pavel, what do you think of it ? Looks sane, good catch, Pierre. But I'd find out whether these three ipc_ids intersect any cache-line. In other words I'd mark the struct ipc_ids as ____cacheline_aligned and checked for any differences. > Acked-by: Cedric Le Goater > > Thanks, Thanks, Pavel > C. > > >> Signed-off-by: Pierre Peiffer >> --- >> include/linux/ipc_namespace.h | 13 +++++++++++-- >> ipc/msg.c | 26 ++++---------------------- >> ipc/namespace.c | 25 ++++--------------------- >> ipc/sem.c | 26 ++++---------------------- >> ipc/shm.c | 26 ++++---------------------- >> ipc/util.c | 6 +++--- >> ipc/util.h | 16 ++++------------ >> 7 files changed, 34 insertions(+), 104 deletions(-) >> >> Index: b/include/linux/ipc_namespace.h >> =================================================================== >> --- a/include/linux/ipc_namespace.h >> +++ b/include/linux/ipc_namespace.h >> @@ -2,11 +2,20 @@ >> #define __IPC_NAMESPACE_H__ >> >> #include >> +#include >> +#include >> + >> +struct ipc_ids { >> + int in_use; >> + unsigned short seq; >> + unsigned short seq_max; >> + struct rw_semaphore rw_mutex; >> + struct idr ipcs_idr; >> +}; >> >> -struct ipc_ids; >> struct ipc_namespace { >> struct kref kref; >> - struct ipc_ids *ids[3]; >> + struct ipc_ids ids[3]; >> >> int sem_ctls[4]; >> int used_sems; >> Index: b/ipc/msg.c >> =================================================================== >> --- a/ipc/msg.c >> +++ b/ipc/msg.c >> @@ -67,9 +67,7 @@ struct msg_sender { >> #define SEARCH_NOTEQUAL 3 >> #define SEARCH_LESSEQUAL 4 >> >> -static struct ipc_ids init_msg_ids; >> - >> -#define msg_ids(ns) (*((ns)->ids[IPC_MSG_IDS])) >> +#define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS]) >> >> #define msg_unlock(msq) ipc_unlock(&(msq)->q_perm) >> #define msg_buildid(id, seq) ipc_buildid(id, seq) >> @@ -80,30 +78,17 @@ static int newque(struct ipc_namespace * >> static int sysvipc_msg_proc_show(struct seq_file *s, void *it); >> #endif >> >> -static void __msg_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids) >> +void msg_init_ns(struct ipc_namespace *ns) >> { >> - ns->ids[IPC_MSG_IDS] = ids; >> ns->msg_ctlmax = MSGMAX; >> ns->msg_ctlmnb = MSGMNB; >> ns->msg_ctlmni = MSGMNI; >> atomic_set(&ns->msg_bytes, 0); >> atomic_set(&ns->msg_hdrs, 0); >> - ipc_init_ids(ids); >> + ipc_init_ids(&ns->ids[IPC_MSG_IDS]); >> } >> >> #ifdef CONFIG_IPC_NS >> -int msg_init_ns(struct ipc_namespace *ns) >> -{ >> - struct ipc_ids *ids; >> - >> - ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL); >> - if (ids == NULL) >> - return -ENOMEM; >> - >> - __msg_init_ns(ns, ids); >> - return 0; >> -} >> - >> void msg_exit_ns(struct ipc_namespace *ns) >> { >> struct msg_queue *msq; >> @@ -126,15 +111,12 @@ void msg_exit_ns(struct ipc_namespace *n >> } >> >> up_write(&msg_ids(ns).rw_mutex); >> - >> - kfree(ns->ids[IPC_MSG_IDS]); >> - ns->ids[IPC_MSG_IDS] = NULL; >> } >> #endif >> >> void __init msg_init(void) >> { >> - __msg_init_ns(&init_ipc_ns, &init_msg_ids); >> + msg_init_ns(&init_ipc_ns); >> ipc_init_proc_interface("sysvipc/msg", >> " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n", >> IPC_MSG_IDS, sysvipc_msg_proc_show); >> Index: b/ipc/namespace.c >> =================================================================== >> --- a/ipc/namespace.c >> +++ b/ipc/namespace.c >> @@ -14,35 +14,18 @@ >> >> static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns) >> { >> - int err; >> struct ipc_namespace *ns; >> >> - err = -ENOMEM; >> ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL); >> if (ns == NULL) >> - goto err_mem; >> + return ERR_PTR(-ENOMEM); >> >> - err = sem_init_ns(ns); >> - if (err) >> - goto err_sem; >> - err = msg_init_ns(ns); >> - if (err) >> - goto err_msg; >> - err = shm_init_ns(ns); >> - if (err) >> - goto err_shm; >> + sem_init_ns(ns); >> + msg_init_ns(ns); >> + shm_init_ns(ns); >> >> kref_init(&ns->kref); >> return ns; >> - >> -err_shm: >> - msg_exit_ns(ns); >> -err_msg: >> - sem_exit_ns(ns); >> -err_sem: >> - kfree(ns); >> -err_mem: >> - return ERR_PTR(err); >> } >> >> struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns) >> Index: b/ipc/sem.c >> =================================================================== >> --- a/ipc/sem.c >> +++ b/ipc/sem.c >> @@ -87,14 +87,12 @@ >> #include >> #include "util.h" >> >> -#define sem_ids(ns) (*((ns)->ids[IPC_SEM_IDS])) >> +#define sem_ids(ns) ((ns)->ids[IPC_SEM_IDS]) >> >> #define sem_unlock(sma) ipc_unlock(&(sma)->sem_perm) >> #define sem_checkid(sma, semid) ipc_checkid(&sma->sem_perm, semid) >> #define sem_buildid(id, seq) ipc_buildid(id, seq) >> >> -static struct ipc_ids init_sem_ids; >> - >> static int newary(struct ipc_namespace *, struct ipc_params *); >> static void freeary(struct ipc_namespace *, struct sem_array *); >> #ifdef CONFIG_PROC_FS >> @@ -118,30 +116,17 @@ static int sysvipc_sem_proc_show(struct >> #define sc_semopm sem_ctls[2] >> #define sc_semmni sem_ctls[3] >> >> -static void __sem_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids) >> +void sem_init_ns(struct ipc_namespace *ns) >> { >> - ns->ids[IPC_SEM_IDS] = ids; >> ns->sc_semmsl = SEMMSL; >> ns->sc_semmns = SEMMNS; >> ns->sc_semopm = SEMOPM; >> ns->sc_semmni = SEMMNI; >> ns->used_sems = 0; >> - ipc_init_ids(ids); >> + ipc_init_ids(&ns->ids[IPC_SEM_IDS]); >> } >> >> #ifdef CONFIG_IPC_NS >> -int sem_init_ns(struct ipc_namespace *ns) >> -{ >> - struct ipc_ids *ids; >> - >> - ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL); >> - if (ids == NULL) >> - return -ENOMEM; >> - >> - __sem_init_ns(ns, ids); >> - return 0; >> -} >> - >> void sem_exit_ns(struct ipc_namespace *ns) >> { >> struct sem_array *sma; >> @@ -163,15 +148,12 @@ void sem_exit_ns(struct ipc_namespace *n >> total++; >> } >> up_write(&sem_ids(ns).rw_mutex); >> - >> - kfree(ns->ids[IPC_SEM_IDS]); >> - ns->ids[IPC_SEM_IDS] = NULL; >> } >> #endif >> >> void __init sem_init (void) >> { >> - __sem_init_ns(&init_ipc_ns, &init_sem_ids); >> + sem_init_ns(&init_ipc_ns); >> ipc_init_proc_interface("sysvipc/sem", >> " key semid perms nsems uid gid cuid cgid otime ctime\n", >> IPC_SEM_IDS, sysvipc_sem_proc_show); >> Index: b/ipc/util.c >> =================================================================== >> --- a/ipc/util.c >> +++ b/ipc/util.c >> @@ -782,7 +782,7 @@ static void *sysvipc_proc_next(struct se >> if (ipc && ipc != SEQ_START_TOKEN) >> ipc_unlock(ipc); >> >> - return sysvipc_find_ipc(iter->ns->ids[iface->ids], *pos, pos); >> + return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos); >> } >> >> /* >> @@ -795,7 +795,7 @@ static void *sysvipc_proc_start(struct s >> struct ipc_proc_iface *iface = iter->iface; >> struct ipc_ids *ids; >> >> - ids = iter->ns->ids[iface->ids]; >> + ids = &iter->ns->ids[iface->ids]; >> >> /* >> * Take the lock - this will be released by the corresponding >> @@ -826,7 +826,7 @@ static void sysvipc_proc_stop(struct seq >> if (ipc && ipc != SEQ_START_TOKEN) >> ipc_unlock(ipc); >> >> - ids = iter->ns->ids[iface->ids]; >> + ids = &iter->ns->ids[iface->ids]; >> /* Release the lock we took in start() */ >> up_read(&ids->rw_mutex); >> } >> Index: b/ipc/util.h >> =================================================================== >> --- a/ipc/util.h >> +++ b/ipc/util.h >> @@ -10,7 +10,6 @@ >> #ifndef _IPC_UTIL_H >> #define _IPC_UTIL_H >> >> -#include >> #include >> >> #define USHRT_MAX 0xffff >> @@ -22,22 +21,14 @@ void shm_init (void); >> >> struct ipc_namespace; >> >> -int sem_init_ns(struct ipc_namespace *ns); >> -int msg_init_ns(struct ipc_namespace *ns); >> -int shm_init_ns(struct ipc_namespace *ns); >> +void sem_init_ns(struct ipc_namespace *ns); >> +void msg_init_ns(struct ipc_namespace *ns); >> +void shm_init_ns(struct ipc_namespace *ns); >> >> void sem_exit_ns(struct ipc_namespace *ns); >> void msg_exit_ns(struct ipc_namespace *ns); >> void shm_exit_ns(struct ipc_namespace *ns); >> >> -struct ipc_ids { >> - int in_use; >> - unsigned short seq; >> - unsigned short seq_max; >> - struct rw_semaphore rw_mutex; >> - struct idr ipcs_idr; >> -}; >> - >> /* >> * Structure that holds the parameters needed by the ipc operations >> * (see after) >> @@ -68,6 +59,7 @@ struct ipc_ops { >> }; >> >> struct seq_file; >> +struct ipc_ids; >> >> void ipc_init_ids(struct ipc_ids *); >> #ifdef CONFIG_PROC_FS >> Index: b/ipc/shm.c >> =================================================================== >> --- a/ipc/shm.c >> +++ b/ipc/shm.c >> @@ -56,9 +56,7 @@ struct shm_file_data { >> static const struct file_operations shm_file_operations; >> static struct vm_operations_struct shm_vm_ops; >> >> -static struct ipc_ids init_shm_ids; >> - >> -#define shm_ids(ns) (*((ns)->ids[IPC_SHM_IDS])) >> +#define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS]) >> >> #define shm_unlock(shp) \ >> ipc_unlock(&(shp)->shm_perm) >> @@ -72,14 +70,13 @@ static void shm_destroy (struct ipc_name >> static int sysvipc_shm_proc_show(struct seq_file *s, void *it); >> #endif >> >> -static void __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids) >> +void shm_init_ns(struct ipc_namespace *ns) >> { >> - ns->ids[IPC_SHM_IDS] = ids; >> ns->shm_ctlmax = SHMMAX; >> ns->shm_ctlall = SHMALL; >> ns->shm_ctlmni = SHMMNI; >> ns->shm_tot = 0; >> - ipc_init_ids(ids); >> + ipc_init_ids(&ns->ids[IPC_SHM_IDS]); >> } >> >> /* >> @@ -98,18 +95,6 @@ static void do_shm_rmid(struct ipc_names >> } >> >> #ifdef CONFIG_IPC_NS >> -int shm_init_ns(struct ipc_namespace *ns) >> -{ >> - struct ipc_ids *ids; >> - >> - ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL); >> - if (ids == NULL) >> - return -ENOMEM; >> - >> - __shm_init_ns(ns, ids); >> - return 0; >> -} >> - >> void shm_exit_ns(struct ipc_namespace *ns) >> { >> struct shmid_kernel *shp; >> @@ -131,15 +116,12 @@ void shm_exit_ns(struct ipc_namespace *n >> total++; >> } >> up_write(&shm_ids(ns).rw_mutex); >> - >> - kfree(ns->ids[IPC_SHM_IDS]); >> - ns->ids[IPC_SHM_IDS] = NULL; >> } >> #endif >> >> void __init shm_init (void) >> { >> - __shm_init_ns(&init_ipc_ns, &init_shm_ids); >> + shm_init_ns(&init_ipc_ns); >> ipc_init_proc_interface("sysvipc/shm", >> " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n", >> IPC_SHM_IDS, sysvipc_shm_proc_show); >> > > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/