diff options
| -rw-r--r-- | sys/sys/proc.h | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/sys/sys/proc.h b/sys/sys/proc.h index b167444..ef1af7e 100644 --- a/sys/sys/proc.h +++ b/sys/sys/proc.h @@ -127,7 +127,7 @@ struct pargs { * b - created at fork, never chagnes * c - locked by proc mtx * d - locked by allproc_lock lock - * e - locked by proc tree lock + * e - locked by proctree_lock lock * f - session mtx * g - process group mtx * h - callout_lock mtx @@ -138,6 +138,16 @@ struct pargs { * l - the attaching proc or attaching proc parent * m - Giant * n - not locked, lazy + * + * If the locking identifier is followed by a plus '+', then the specified + * member follows these special rules: + * - It is only written to by the current process. + * - It can be read by the current process and other processes. + * Thus, the locking rules for it are slightly different, and allow us to + * optimize the case where a process reads its own such value: + * - Writes to this member are locked. + * - Reads of this value by other processes are locked. + * - Reads of this value by the current process need not be locked. */ struct proc { TAILQ_ENTRY(proc) p_procq; /* (j) Run/mutex queue. */ @@ -145,11 +155,11 @@ struct proc { LIST_ENTRY(proc) p_list; /* (d) List of all processes. */ /* substructures: */ - struct pcred *p_cred; /* (c) Process owner's identity. */ + struct pcred *p_cred; /* (c+) Process owner's identity. */ struct filedesc *p_fd; /* (b) Ptr to open files structure. */ struct pstats *p_stats; /* (b) Accounting/statistics (CPU). */ struct plimit *p_limit; /* (m) Process limits. */ - struct vm_object *p_upages_obj;/* (c) Upages object. */ + struct vm_object *p_upages_obj;/* (a) Upages object. */ struct procsig *p_procsig; /* (c) Signal actions, state (CPU). */ #define p_sigacts p_procsig->ps_sigacts #define p_sigignore p_procsig->ps_sigignore @@ -160,7 +170,7 @@ struct proc { int p_flag; /* (c) P_* flags. */ int p_sflag; /* (j) PS_* flags. */ - int p_intr_nesting_level; /* (n) Interrupt recursion. */ + int p_intr_nesting_level; /* (k) Interrupt recursion. */ char p_stat; /* (j) S* process status. */ char p_pad1[3]; |
