user space, such as i/ o The device can be opened with open (2), the network protocol may be opened with a socket (2), etc., and after obtaining a file descriptor, it is possible to invoke the IOCTL (2) on this descriptor to exchange data to the kernel.3. IOCTL (2)The basic use format for the IOCTL (2) function is:int ioctl (int fd, int cmd, void *data)The first parameter is the file descriptor; cmd is an operation command, generally divided into get, set and other types of commands, get is the
; % Haar window Width nr = num-r (I) +1; % moving number in line direction NC = num-c (J) +1; Number of moves in the% column direction Px0 = [0 R]; % Rectangle coordinate initialization Py0 = [0 c/2 c]; For i = 1:nr for j = 1:nc Px = px0+ (i-1) *delta; % sliding Pick-point Py = py0+ (j-1) *
half application is also the reason for motivating the kernel to develop the current Soft Interrupt mechanism. Therefore, we should first start with the implementation of bottom half. Ii. bottom half In the Linux kernel, bottom half usually uses "bh" to indicate that it is initially used to complete non-critical time-consuming actions for service interruption in lower-privilege context, now it is also used for all asynchronous actions that can be performed in lower-priority context. The earli
to as NR, the full name new Radio access Technology in 3GPP, this article is called 5G-NR.
5G-NR Scenarios and KPIs
See TR 38.913 "Study on Scenarios and Requirements for Next Generation Access Technologies"
The 5G defines three main scenarios:
EMBB (Enhanced mobile broadband), enhanced mobile broadband
MMTC (Massive Machine Type Communications), large
: '{print $1}'|sort|uniq -c|sort -nr|head -n20netstat -ant |awk '/:80/{split($5,ip,":");++A[ip[1]]}END{for(i in A) print A,i}' |sort -rn|head -n20
3. Use tcpdump to sniff access to port 80 to see who is the highest
tcpdump -i eth0 -tnn dst port 80 -c 1000 | awk -F"." '{print $1"."$2"."$3"."$4}' | sort | uniq -c | sort -nr |head -20
4. Search for more time_wait connections
netstat -n|grep TIME_WAIT|awk
tasklet_schedule function to run tasklet.
Static inline void tasklet_schedule (struct tasklet_struct * t){If (! Test_and_set_bit (tasklet_state_sched, T-> State ))_ Tasklet_schedule (t );}
Function _ tasklet_schedule obtains the tasklet_vec linked list of the current CPU, and executes the tasklet_softirq Soft Interrupt.
Void fastcall _ tasklet_schedule (struct tasklet_struct * t){Unsigned long flags;
Local_irq_save (flags );T-> next = _ get_cpu_var (tasklet_vec). List;_ Get_cpu_var (tasklet_ve
Read routine, and uses* Mapping-> a_ops-> readpage () function for the actual low-level stuff.*/Void do_generic_mapping_read (struct address_space * mapping,Struct file_ra_state * _ Ra,Struct file * filp,Loff_t * PPOs,Read_descriptor_t * DESC,Read_actor_t actor){Struct inode * inode = mapping-> host;Unsigned long index;Unsigned long end_index;Unsigned long offset;Unsigned long last_index;Unsigned long next_index;Unsigned long prev_index;Loff_t isize;Struct page * cached_page;Int error;Struct fi
Linux-related Interview Questions answers, linux-related questions
Linux-related Interview Questions Answers
Linux Interview Questions Answers
Assume that the apache log format is:118.78.199.98--[09/Jan/2010: 00: 59: 59 + 0800] "GET/Public/Css/index.css HTTP/1.1" 304-"http://www.a.cn/common/index.php" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; GTB6.3 )"
Problem 1: In apachelog, find the top 10 IP addresses with the most accesses.Awk '{print $1}' apache_log | sort | uniq-c | sor
1. Delete the first character of each line of the file.Sed ' s/.//' install.logSed-n ' S/^.//GP '/etc/passwd Sed-nr ' s/(.) (. *)/\2/p '/etc/passwd2. Delete the second character of each line of the file.Sed ' S/.//2 ' install.logSed ' s/(.) (.) (. *)/1\3\/' Install.logSed-nr ' s/(.) (.) (. *)/\1\3/p '/etc/passwd3. Delete the last character of each line of the file.sed ' s/.$//' install.logSed-
$ Sed-e '/test/h '-e '/check/x ' example
Swaps the pattern space and preserves the contents of the buffer. That is, the line that contains test and check is swapped.Nine, practice1. Delete the first character of each line of the file.
Sed-n ' S/^.//GP '/etc/passwd
Sed-nr ' s/(.) (. *)/\2/p '/etc/passwd
2. Delete the second character of each line of the file.
Sed-nr
)(4) MAJFLT/S: The number of main pages generated per second(5) pgfree/s: Number of pages per second that are placed in the idle queue(6) pgscank/s: Number of pages scanned by KSWAPD per second(7) pgscand/s: Number of pages scanned directly per second(8) PGSTEAL/S: The number of pages per second that are purged from the cache to meet memory requirements(9)%vmeff: The percentage of pages (Pgsteal) purged per second that are the Total Scan page (Pgscank+pgscand).
Monitoring of I nodes, files and
tabawk built-in variablesSave the content of Awk's current read releaseFileName to save the file name of awk currently working on filesNR Save the number of rows that awk is currently working onFNR Save the number of rows in the file that awk is currently working onNF Store the number of the current row, column (field) after splitting with the specified split symbol$ ... $n represents the field after the data is split with the specified separatorVariable 1th column $2nd ColumnFS save field spli
a "\ t" COUNT [a] "\ n"} 'www.2cto.com 2. for more than 20 requests, see netstat-anlp | grep 80 | grep tcp | awk '{print $5}' | awk-F: '{print $1}' | sort | uniq-c | sort-nr | head-n20 netstat-ant | awk '/: 80/{split ($5, ip, ":"); ++ A [ip [1]} END {for (I in A) print A [I], i} '| sort-rn | head-n20 3. use tcpdump to sniff access to port 80 to see who has the highest tcpdump-I eth0-tnn dst port 80-c 1000 | awk-F ". "'{print $1 ". "$2 ". "$3 ". "$4}
sed jobs:1. Delete the first character of each line of the file.Sed ' s/.//' install.logSed-n ' S/^.//GP '/etc/passwd sed-nr ' s/(.) (. *)/\2/p '/etc/passwd2, delete the second character of each line of the file.Sed ' S/.//2 ' install.logSed ' s/(.) (.) (. *)/1\3\/' Install.logSed-nr ' s/(.) (.) (. *)/\1\3/p '/etc/passwd3. Delete the last character of each line of the file.Sed ' s/.$//' install.logSed-
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.