minix/kernel/proc.h
Tomas Hruby f51eea4b32 Changed pagefault delivery to VM
this patch changes the way pagefaults are delivered to VM. It adopts
the same model as the out-of-quantum messages sent by kernel to a
scheduler.

- everytime a userspace pagefault occurs, kernel creates a message
  which is sent to VM on behalf of the faulting process

- the process is blocked on delivery to VM in the standard IPC code
  instead of waiting in a spacial in-kernel queue (stack) and is not
  runnable until VM tell kernel that the pagefault is resolved and is
  free to clear the RTS_PAGEFAULT flag.

- VM does not need call kernel and poll the pagefault information
  which saves many (1/2?) calls and kernel calls that return "no more
  data"

- VM notification by kernel does not need to use signals

- each entry in proc table is by 12 bytes smaller (~3k save)
2010-04-26 23:21:26 +00:00

268 lines
9.9 KiB
C

#ifndef PROC_H
#define PROC_H
#ifndef __ASSEMBLY__
/* Here is the declaration of the process table. It contains all process
* data, including registers, flags, scheduling priority, memory map,
* accounting, message passing (IPC) information, and so on.
*
* Many assembly code routines reference fields in it. The offsets to these
* fields are defined in the assembler include file sconst.h. When changing
* struct proc, be sure to change sconst.h to match.
*/
#include <minix/com.h>
#include <minix/portio.h>
#include "const.h"
#include "priv.h"
struct proc {
struct stackframe_s p_reg; /* process' registers saved in stack frame */
struct fpu_state_s p_fpu_state; /* process' fpu_regs saved lazily */
struct segframe p_seg; /* segment descriptors */
proc_nr_t p_nr; /* number of this process (for fast access) */
struct priv *p_priv; /* system privileges structure */
short p_rts_flags; /* process is runnable only if zero */
short p_misc_flags; /* flags that do not suspend the process */
char p_priority; /* current process priority */
char p_ticks_left; /* number of scheduling ticks left */
char p_quantum_size; /* quantum size in ticks */
struct proc *p_scheduler; /* who should get out of quantum msg */
struct mem_map p_memmap[NR_LOCAL_SEGS]; /* memory map (T, D, S) */
clock_t p_user_time; /* user time in ticks */
clock_t p_sys_time; /* sys time in ticks */
clock_t p_virt_left; /* number of ticks left on virtual timer */
clock_t p_prof_left; /* number of ticks left on profile timer */
u64_t p_cycles; /* how many cycles did the process use */
struct proc *p_nextready; /* pointer to next ready process */
struct proc *p_caller_q; /* head of list of procs wishing to send */
struct proc *p_q_link; /* link to next proc wishing to send */
endpoint_t p_getfrom_e; /* from whom does process want to receive? */
endpoint_t p_sendto_e; /* to whom does process want to send? */
sigset_t p_pending; /* bit map for pending kernel signals */
char p_name[P_NAME_LEN]; /* name of the process, including \0 */
endpoint_t p_endpoint; /* endpoint number, generation-aware */
message p_sendmsg; /* Message from this process if SENDING */
message p_delivermsg; /* Message for this process if MF_DELIVERMSG */
vir_bytes p_delivermsg_vir; /* Virtual addr this proc wants message at */
vir_bytes p_delivermsg_lin; /* Linear addr this proc wants message at */
/* If handler functions detect a process wants to do something with
* memory that isn't present, VM has to fix it. Until it has asked
* what needs to be done and fixed it, save necessary state here.
*
* The requestor gets a copy of its request message in reqmsg and gets
* VMREQUEST set.
*/
struct {
struct proc *nextrestart; /* next in vmrestart chain */
struct proc *nextrequestor; /* next in vmrequest chain */
#define VMSTYPE_SYS_NONE 0
#define VMSTYPE_KERNELCALL 1
#define VMSTYPE_DELIVERMSG 2
#define VMSTYPE_MAP 3
int type; /* suspended operation */
union {
/* VMSTYPE_SYS_MESSAGE */
message reqmsg; /* suspended request message */
} saved;
/* Parameters of request to VM */
int req_type;
endpoint_t target;
union {
struct {
vir_bytes start, length; /* memory range */
u8_t writeflag; /* nonzero for write access */
} check;
struct {
char writeflag;
endpoint_t ep_s;
vir_bytes vir_s, vir_d;
vir_bytes length;
} map;
} params;
/* VM result when available */
int vmresult;
/* If the suspended operation is a sys_call, its details are
* stored here.
*/
} p_vmrequest;
int p_found; /* consistency checking variables */
#define PMAGIC 0xC0FFEE1
int p_magic; /* check validity of proc pointers */
#if DEBUG_TRACE
int p_schedules;
#endif
};
#endif /* __ASSEMBLY__ */
/* Bits for the runtime flags. A process is runnable iff p_rts_flags == 0. */
#define RTS_SLOT_FREE 0x01 /* process slot is free */
#define RTS_PROC_STOP 0x02 /* process has been stopped */
#define RTS_SENDING 0x04 /* process blocked trying to send */
#define RTS_RECEIVING 0x08 /* process blocked trying to receive */
#define RTS_SIGNALED 0x10 /* set when new kernel signal arrives */
#define RTS_SIG_PENDING 0x20 /* unready while signal being processed */
#define RTS_P_STOP 0x40 /* set when process is being traced */
#define RTS_NO_PRIV 0x80 /* keep forked system process from running */
#define RTS_NO_ENDPOINT 0x100 /* process cannot send or receive messages */
#define RTS_VMINHIBIT 0x200 /* not scheduled until pagetable set by VM */
#define RTS_PAGEFAULT 0x400 /* process has unhandled pagefault */
#define RTS_VMREQUEST 0x800 /* originator of vm memory request */
#define RTS_VMREQTARGET 0x1000 /* target of vm memory request */
#define RTS_PREEMPTED 0x4000 /* this process was preempted by a higher
priority process and we should pick a new one
to run. Processes with this flag should be
returned to the front of their current
priority queue if they are still runnable
before we pick a new one
*/
#define RTS_NO_QUANTUM 0x8000 /* process ran out of its quantum and we should
pick a new one. Process was dequeued and
should be enqueued at the end of some run
queue again */
/* A process is runnable iff p_rts_flags == 0. */
#define rts_f_is_runnable(flg) ((flg) == 0)
#define proc_is_runnable(p) (rts_f_is_runnable((p)->p_rts_flags))
#define proc_is_preempted(p) ((p)->p_rts_flags & RTS_PREEMPTED)
#define proc_no_quantum(p) ((p)->p_rts_flags & RTS_NO_QUANTUM)
#define proc_ptr_ok(p) ((p)->p_magic == PMAGIC)
/* test whether the process is scheduled by the kernel's default policy */
#define proc_kernel_scheduler(p) ((p)->p_scheduler == NULL || \
(p)->p_scheduler == (p))
/* Macro to return: on which process is a certain process blocked?
* return endpoint number (can be ANY) or NONE. It's important to
* check RTS_SENDING first, and then RTS_RECEIVING, as they could
* both be on (if a sendrec() blocks on sending), and p_getfrom_e
* could be nonsense even though RTS_RECEIVING is on.
*/
#define P_BLOCKEDON(p) \
( \
((p)->p_rts_flags & RTS_SENDING) ? \
(p)->p_sendto_e : \
( \
( \
((p)->p_rts_flags & RTS_RECEIVING) ? \
(p)->p_getfrom_e : \
NONE \
) \
) \
)
/* These runtime flags can be tested and manipulated by these macros. */
#define RTS_ISSET(rp, f) (((rp)->p_rts_flags & (f)) == (f))
/* Set flag and dequeue if the process was runnable. */
#define RTS_SET(rp, f) \
do { \
const int rts = (rp)->p_rts_flags; \
(rp)->p_rts_flags |= (f); \
if(rts_f_is_runnable(rts) && !proc_is_runnable(rp)) { \
dequeue(rp); \
} \
} while(0)
/* Clear flag and enqueue if the process was not runnable but is now. */
#define RTS_UNSET(rp, f) \
do { \
int rts; \
rts = (rp)->p_rts_flags; \
(rp)->p_rts_flags &= ~(f); \
if(!rts_f_is_runnable(rts) && proc_is_runnable(rp)) { \
enqueue(rp); \
} \
} while(0)
/* Set flags to this value. */
#define RTS_SETFLAGS(rp, f) \
do { \
if(proc_is_runnable(rp) && (f)) { dequeue(rp); } \
(rp)->p_rts_flags = (f); \
} while(0)
/* Misc flags */
#define MF_REPLY_PEND 0x001 /* reply to IPC_REQUEST is pending */
#define MF_VIRT_TIMER 0x002 /* process-virtual timer is running */
#define MF_PROF_TIMER 0x004 /* process-virtual profile timer is running */
#define MF_KCALL_RESUME 0x008 /* processing a kernel call was interrupted,
most likely because we need VM to resolve a
problem or a long running copy was preempted.
We need to resume the kernel call execution
now
*/
#define MF_ASYNMSG 0x010 /* Asynchrous message pending */
#define MF_FULLVM 0x020
#define MF_DELIVERMSG 0x040 /* Copy message for him before running */
#define MF_SIG_DELAY 0x080 /* Send signal when no longer sending */
#define MF_SC_ACTIVE 0x100 /* Syscall tracing: in a system call now */
#define MF_SC_DEFER 0x200 /* Syscall tracing: deferred system call */
#define MF_SC_TRACE 0x400 /* Syscall tracing: trigger syscall events */
#define MF_USED_FPU 0x800 /* process used fpu during last execution run */
#define MF_FPU_INITIALIZED 0x1000 /* process already used math, so fpu
* regs are significant (initialized)*/
#define MF_SENDING_FROM_KERNEL 0x2000 /* message of this process is from kernel */
/* Scheduling priorities for p_priority. Values must start at zero (highest
* priority) and increment. Priorities of the processes in the boot image
* can be set in table.c.
*/
#define NR_SCHED_QUEUES 16 /* MUST equal minimum priority + 1 */
#define TASK_Q 0 /* highest, used for kernel tasks */
#define MAX_USER_Q 0 /* highest priority for user processes */
#define USER_Q (NR_SCHED_QUEUES / 2) /* default (should correspond to
nice 0) */
#define MIN_USER_Q (NR_SCHED_QUEUES - 1) /* minimum priority for user
processes */
/* Magic process table addresses. */
#define BEG_PROC_ADDR (&proc[0])
#define BEG_USER_ADDR (&proc[NR_TASKS])
#define END_PROC_ADDR (&proc[NR_TASKS + NR_PROCS])
#define cproc_addr(n) (&(proc + NR_TASKS)[(n)])
#define proc_addr(n) (&(proc[NR_TASKS + (n)]))
#define proc_nr(p) ((p)->p_nr)
#define isokprocn(n) ((unsigned) ((n) + NR_TASKS) < NR_PROCS + NR_TASKS)
#define isemptyn(n) isemptyp(proc_addr(n))
#define isemptyp(p) ((p)->p_rts_flags == RTS_SLOT_FREE)
#define iskernelp(p) ((p) < BEG_USER_ADDR)
#define iskerneln(n) ((n) < 0)
#define isuserp(p) isusern((p) >= BEG_USER_ADDR)
#define isusern(n) ((n) >= 0)
#define isrootsysn(n) ((n) == ROOT_SYS_PROC_NR)
#ifndef __ASSEMBLY__
EXTERN struct proc proc[NR_TASKS + NR_PROCS]; /* process table */
EXTERN struct proc *rdy_head[NR_SCHED_QUEUES]; /* ptrs to ready list headers */
EXTERN struct proc *rdy_tail[NR_SCHED_QUEUES]; /* ptrs to ready list tails */
_PROTOTYPE( int mini_send, (struct proc *caller_ptr, int dst_e,
message *m_ptr, int flags));
#endif /* __ASSEMBLY__ */
#endif /* PROC_H */