diff options
Diffstat (limited to 'Documentation/filesystems/proc.txt')
| -rw-r--r-- | Documentation/filesystems/proc.txt | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 12a5e6e693b6..66cad5c86171 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -125,6 +125,13 @@ process running on the system, which is named after the process ID (PID). The link self points to the process reading the file system. Each process subdirectory has the entries listed in Table 1-1. +Note that an open a file descriptor to /proc/<pid> or to any of its +contained files or subdirectories does not prevent <pid> being reused +for some other process in the event that <pid> exits. Operations on +open /proc/<pid> file descriptors corresponding to dead processes +never act on any new process that the kernel may, through chance, have +also assigned the process ID <pid>. Instead, operations on these FDs +usually fail with ESRCH. Table 1-1: Process specific entries in /proc .............................................................................. @@ -182,6 +189,7 @@ read the file /proc/PID/status: VmSwap: 0 kB HugetlbPages: 0 kB CoreDumping: 0 + THP_enabled: 1 Threads: 1 SigQ: 0/28578 SigPnd: 0000000000000000 @@ -193,8 +201,10 @@ read the file /proc/PID/status: CapPrm: 0000000000000000 CapEff: 0000000000000000 CapBnd: ffffffffffffffff + CapAmb: 0000000000000000 NoNewPrivs: 0 Seccomp: 0 + Speculation_Store_Bypass: thread vulnerable voluntary_ctxt_switches: 0 nonvoluntary_ctxt_switches: 1 @@ -214,7 +224,7 @@ asynchronous manner and the value may not be very precise. To see a precise snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table. It's slow but very precise. -Table 1-2: Contents of the status files (as of 4.8) +Table 1-2: Contents of the status files (as of 4.19) .............................................................................. Field Content Name filename of the executable @@ -256,6 +266,8 @@ Table 1-2: Contents of the status files (as of 4.8) HugetlbPages size of hugetlb memory portions CoreDumping process's memory is currently being dumped (killing the process may lead to a corrupted core) + THP_enabled process is allowed to use THP (returns 0 when + PR_SET_THP_DISABLE is set on the process Threads number of threads SigQ number of signals queued/max. number for queue SigPnd bitmap of pending signals for the thread @@ -267,8 +279,10 @@ Table 1-2: Contents of the status files (as of 4.8) CapPrm bitmap of permitted capabilities CapEff bitmap of effective capabilities CapBnd bitmap of capabilities bounding set + CapAmb bitmap of ambient capabilities NoNewPrivs no_new_privs, like prctl(PR_GET_NO_NEW_PRIV, ...) Seccomp seccomp mode, like prctl(PR_GET_SECCOMP, ...) + Speculation_Store_Bypass speculative store bypass mitigation status Cpus_allowed mask of CPUs on which this process may run Cpus_allowed_list Same as previous, but in "list format" Mems_allowed mask of memory nodes allowed to this process @@ -425,6 +439,7 @@ SwapPss: 0 kB KernelPageSize: 4 kB MMUPageSize: 4 kB Locked: 0 kB +THPeligible: 0 VmFlags: rd ex mr mw me dw the first of these lines shows the same information as is displayed for the @@ -462,6 +477,8 @@ replaced by copy-on-write) part of the underlying shmem object out on swap. "SwapPss" shows proportional swap share of this mapping. Unlike "Swap", this does not take into account swapped out page of underlying shmem objects. "Locked" indicates whether the mapping is locked in memory or not. +"THPeligible" indicates whether the mapping is eligible for THP pages - 1 if +true, 0 otherwise. "VmFlags" field deserves a separate description. This member represents the kernel flags associated with the particular virtual memory area in two letter encoded @@ -496,7 +513,9 @@ manner. The codes are the following: Note that there is no guarantee that every flag and associated mnemonic will be present in all further kernel releases. Things get changed, the flags may -be vanished or the reverse -- new added. +be vanished or the reverse -- new added. Interpretation of their meaning +might change in future as well. So each consumer of these flags has to +follow each specific kernel version for the exact semantic. This file is only present if the CONFIG_MMU kernel configuration option is enabled. |