X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=Documentation%2Ffilesystems%2Fproc.txt;h=0dad0f2b059cb01a60b9044236f52cc7ab5e50f1;hb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;hp=378722d5bb704f2487621cef3590b2a82cbbe085;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 378722d5b..0dad0f2b0 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -55,7 +55,7 @@ This work is based on the 2.2.* kernel version and the upcoming 2.4.*. I'm afraid it's still far from complete, but we hope it will be useful. As far as we know, it is the first 'all-in-one' document about the /proc file system. It is focused on the Intel x86 hardware, so if you are looking for PPC, ARM, -SPARC, APX, etc., features, you probably won't find what you are looking for. +SPARC, AXP, etc., features, you probably won't find what you are looking for. It also only covers IPv4 networking, not IPv6 nor other protocols - sorry. But additions and patches are welcome and will be added to this document if you mail them to Bodo. @@ -169,16 +169,18 @@ information. The statm file contains more detailed information about the process memory usage. Its seven fields are explained in Table 1-2. -Table 1-2: Contents of the statm files +Table 1-2: Contents of the statm files (as of 2.6.8-rc3) .............................................................................. - File Content - size total program size - resident size of memory portions - shared number of pages that are shared - trs number of pages that are 'code' - drs number of pages of data/stack - lrs number of pages of library - dt number of dirty pages + Field Content + size total program size (pages) (same as VmSize in status) + resident size of memory portions (pages) (same as VmRSS in status) + shared number of pages that are shared (i.e. backed by a file) + trs number of pages that are 'code' (not including libs; broken, + includes data segment) + lrs number of pages of library (always 0 on 2.6) + drs number of pages of data/stack (including libs; broken, + includes library text) + dt number of dirty pages (always 0 on 2.6) .............................................................................. 1.2 Kernel data @@ -201,7 +203,7 @@ Table 1-3: Kernel info in /proc devices Available devices (block and character) dma Used DMS channels filesystems Supported filesystems - driver Various drivers grouped here, currently rtc (2.4) + driver Various drivers grouped here, currently rtc (2.4) execdomains Execdomains, related to security (2.4) fb Frame Buffer devices (2.4) fs File system parameters, currently nfs/exports (2.4) @@ -852,7 +854,8 @@ this time. The value in file-max denotes the maximum number of file handles that the Linux kernel will allocate. When you get a lot of error messages about running out of file handles, you might want to raise this limit. The default value is -4096. To change it, just write the new number into the file: +10% of RAM in kilobytes. To change it, just write the new number into the +file: # cat /proc/sys/fs/file-max 4096 @@ -864,11 +867,14 @@ out of file handles, you might want to raise this limit. The default value is This method of revision is useful for all customizable parameters of the kernel - simply echo the new value to the corresponding file. -The three values in file-nr denote the number of allocated file handles, the -number of used file handles, and the maximum number of file handles. When the -allocated file handles come close to the maximum, but the number of actually -used ones is far behind, you've encountered a peak in your usage of file -handles and you don't need to increase the maximum. +Historically, the three values in file-nr denoted the number of allocated file +handles, the number of allocated but unused file handles, and the maximum +number of file handles. Linux 2.6 always reports 0 as the number of free file +handles -- this is not an error, it just means that the number of allocated +file handles exactly matches the number of used file handles. + +Attempts to allocate more file descriptors than file-max are reported with +printk, look for "VFS: file-max limit reached". inode-state and inode-nr ------------------------ @@ -1105,12 +1111,41 @@ modprobe The location where the modprobe binary is located. The kernel uses this program to load modules on demand. +unknown_nmi_panic +----------------- + +The value in this file affects behavior of handling NMI. When the value is +non-zero, unknown NMI is trapped and then panic occurs. At that time, kernel +debugging information is displayed on console. + +NMI switch that most IA32 servers have fires unknown NMI up, for example. +If a system hangs up, try pressing the NMI switch. + +[NOTE] + This function and oprofile share a NMI callback. Therefore this function + cannot be enabled when oprofile is activated. + And NMI watchdog will be disabled when the value in this file is set to + non-zero. + + 2.4 /proc/sys/vm - The virtual memory subsystem ----------------------------------------------- The files in this directory can be used to tune the operation of the virtual memory (VM) subsystem of the Linux kernel. +vfs_cache_pressure +------------------ + +Controls the tendency of the kernel to reclaim the memory which is used for +caching of directory and inode objects. + +At the default value of vfs_cache_pressure=100 the kernel will attempt to +reclaim dentries and inodes at a "fair" rate with respect to pagecache and +swapcache reclaim. Decreasing vfs_cache_pressure causes the kernel to prefer +to retain dentry and inode caches. Increasing vfs_cache_pressure beyond 100 +causes the kernel to prefer to reclaim dentries and inodes. + dirty_background_ratio ---------------------- @@ -1141,6 +1176,12 @@ for writeout by the pdflush daemons. It is expressed in 100'ths of a second. Data which has been dirty in-memory for longer than this interval will be written out next time a pdflush daemon wakes up. +legacy_va_layout +---------------- + +If non-zero, this sysctl disables the new 32-bit mmap mmap layout - the kernel +will use the legacy (2.4) layout for all processes. + lower_zone_protection --------------------- @@ -1208,6 +1249,26 @@ On the other hand, enabling this feature can cause you to run out of memory and thrash the system to death, so large and/or important servers will want to set this value to 0. +nr_hugepages and hugetlb_shm_group +---------------------------------- + +nr_hugepages configures number of hugetlb page reserved for the system. + +hugetlb_shm_group contains group id that is allowed to create SysV shared +memory segment using hugetlb page. + +laptop_mode +----------- + +laptop_mode is a knob that controls "laptop mode". All the things that are +controlled by this knob are discussed in Documentation/laptop-mode.txt. + +block_dump +---------- + +block_dump enables block I/O debugging when set to a nonzero value. More +information on block I/O debugging is in Documentation/laptop-mode.txt. + 2.5 /proc/sys/dev - Device specific parameters ---------------------------------------------- @@ -1628,7 +1689,8 @@ flush Writing to this file results in a flush of the routing cache. -gc_elastic, gc_interval, gc_min_interval, gc_tresh, gc_timeout +gc_elasticity, gc_interval, gc_min_interval, gc_tresh, gc_timeout, +gc_thresh, gc_thresh1, gc_thresh2, gc_thresh3 -------------------------------------------------------------- Values to control the frequency and behavior of the garbage collection @@ -1848,10 +1910,3 @@ need to recompile the kernel, or even to reboot the system. The files in the command to write value into these files, thereby changing the default settings of the kernel. ------------------------------------------------------------------------------ - - - - - - -