mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-21 08:27:01 +07:00
15df03c879
For a custom microbenchmark on a 3.30GHz Xeon SandyBridge, which calls
IPC_STAT over and over, it was calculated that, on avg the cost of
ipc_get_maxid() for increasing amounts of keys was:
10 keys: ~900 cycles
100 keys: ~15000 cycles
1000 keys: ~150000 cycles
10000 keys: ~2100000 cycles
This is unsurprising as maxid is currently O(n).
By having the max_id available in O(1) we save all those cycles for each
semctl(_STAT) command, the idr_find can be expensive -- which some real
(customer) workloads actually poll on.
Note that this used to be the case, until commit 7ca7e564e0 ("ipc:
store ipcs into IDRs"). The cost is the extra idr_find when doing
RMIDs, but we simply go backwards, and should not take too many
iterations to find the new value.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170831172049.14576-5-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
168 lines
4.5 KiB
C
168 lines
4.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __IPC_NAMESPACE_H__
|
|
#define __IPC_NAMESPACE_H__
|
|
|
|
#include <linux/err.h>
|
|
#include <linux/idr.h>
|
|
#include <linux/rwsem.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/nsproxy.h>
|
|
#include <linux/ns_common.h>
|
|
#include <linux/refcount.h>
|
|
#include <linux/rhashtable.h>
|
|
|
|
struct user_namespace;
|
|
|
|
struct ipc_ids {
|
|
int in_use;
|
|
unsigned short seq;
|
|
bool tables_initialized;
|
|
struct rw_semaphore rwsem;
|
|
struct idr ipcs_idr;
|
|
int max_id;
|
|
#ifdef CONFIG_CHECKPOINT_RESTORE
|
|
int next_id;
|
|
#endif
|
|
struct rhashtable key_ht;
|
|
};
|
|
|
|
struct ipc_namespace {
|
|
refcount_t count;
|
|
struct ipc_ids ids[3];
|
|
|
|
int sem_ctls[4];
|
|
int used_sems;
|
|
|
|
unsigned int msg_ctlmax;
|
|
unsigned int msg_ctlmnb;
|
|
unsigned int msg_ctlmni;
|
|
atomic_t msg_bytes;
|
|
atomic_t msg_hdrs;
|
|
|
|
size_t shm_ctlmax;
|
|
size_t shm_ctlall;
|
|
unsigned long shm_tot;
|
|
int shm_ctlmni;
|
|
/*
|
|
* Defines whether IPC_RMID is forced for _all_ shm segments regardless
|
|
* of shmctl()
|
|
*/
|
|
int shm_rmid_forced;
|
|
|
|
struct notifier_block ipcns_nb;
|
|
|
|
/* The kern_mount of the mqueuefs sb. We take a ref on it */
|
|
struct vfsmount *mq_mnt;
|
|
|
|
/* # queues in this ns, protected by mq_lock */
|
|
unsigned int mq_queues_count;
|
|
|
|
/* next fields are set through sysctl */
|
|
unsigned int mq_queues_max; /* initialized to DFLT_QUEUESMAX */
|
|
unsigned int mq_msg_max; /* initialized to DFLT_MSGMAX */
|
|
unsigned int mq_msgsize_max; /* initialized to DFLT_MSGSIZEMAX */
|
|
unsigned int mq_msg_default;
|
|
unsigned int mq_msgsize_default;
|
|
|
|
/* user_ns which owns the ipc ns */
|
|
struct user_namespace *user_ns;
|
|
struct ucounts *ucounts;
|
|
|
|
struct ns_common ns;
|
|
} __randomize_layout;
|
|
|
|
extern struct ipc_namespace init_ipc_ns;
|
|
extern spinlock_t mq_lock;
|
|
|
|
#ifdef CONFIG_SYSVIPC
|
|
extern void shm_destroy_orphaned(struct ipc_namespace *ns);
|
|
#else /* CONFIG_SYSVIPC */
|
|
static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
|
|
#endif /* CONFIG_SYSVIPC */
|
|
|
|
#ifdef CONFIG_POSIX_MQUEUE
|
|
extern int mq_init_ns(struct ipc_namespace *ns);
|
|
/*
|
|
* POSIX Message Queue default values:
|
|
*
|
|
* MIN_*: Lowest value an admin can set the maximum unprivileged limit to
|
|
* DFLT_*MAX: Default values for the maximum unprivileged limits
|
|
* DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
|
|
* an attribute to the open call and the queue must be created
|
|
* HARD_*: Highest value the maximums can be set to. These are enforced
|
|
* on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
|
|
* suitably high)
|
|
*
|
|
* POSIX Requirements:
|
|
* Per app minimum openable message queues - 8. This does not map well
|
|
* to the fact that we limit the number of queues on a per namespace
|
|
* basis instead of a per app basis. So, make the default high enough
|
|
* that no given app should have a hard time opening 8 queues.
|
|
* Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536.
|
|
* Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However,
|
|
* we have run into a situation where running applications in the wild
|
|
* require this to be at least 5MB, and preferably 10MB, so I set the
|
|
* value to 16MB in hopes that this user is the worst of the bunch and
|
|
* the new maximum will handle anyone else. I may have to revisit this
|
|
* in the future.
|
|
*/
|
|
#define DFLT_QUEUESMAX 256
|
|
#define MIN_MSGMAX 1
|
|
#define DFLT_MSG 10U
|
|
#define DFLT_MSGMAX 10
|
|
#define HARD_MSGMAX 65536
|
|
#define MIN_MSGSIZEMAX 128
|
|
#define DFLT_MSGSIZE 8192U
|
|
#define DFLT_MSGSIZEMAX 8192
|
|
#define HARD_MSGSIZEMAX (16*1024*1024)
|
|
#else
|
|
static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
|
|
#endif
|
|
|
|
#if defined(CONFIG_IPC_NS)
|
|
extern struct ipc_namespace *copy_ipcs(unsigned long flags,
|
|
struct user_namespace *user_ns, struct ipc_namespace *ns);
|
|
|
|
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
|
|
{
|
|
if (ns)
|
|
refcount_inc(&ns->count);
|
|
return ns;
|
|
}
|
|
|
|
extern void put_ipc_ns(struct ipc_namespace *ns);
|
|
#else
|
|
static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
|
|
struct user_namespace *user_ns, struct ipc_namespace *ns)
|
|
{
|
|
if (flags & CLONE_NEWIPC)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
return ns;
|
|
}
|
|
|
|
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
|
|
{
|
|
return ns;
|
|
}
|
|
|
|
static inline void put_ipc_ns(struct ipc_namespace *ns)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_POSIX_MQUEUE_SYSCTL
|
|
|
|
struct ctl_table_header;
|
|
extern struct ctl_table_header *mq_register_sysctl_table(void);
|
|
|
|
#else /* CONFIG_POSIX_MQUEUE_SYSCTL */
|
|
|
|
static inline struct ctl_table_header *mq_register_sysctl_table(void)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
|
|
#endif
|