Brendan Gregg

OCTOBER 8, 2018

Screenshot: tracing read latency for PID 181: # bpftrace -e 'kprobe:vfs_read /pid == 30153/ { @start[tid] = nsecs; } kretprobe:vfs_read /@start[tid]/ { @ns = hist(nsecs - @start[tid]); delete(@start[tid]); }'. Hit Ctrl-C to end.n"); } self int last[dev_t]; /* * Process io start */ io:genunix::start /self->last[args[0]->b_edev] !=

C++ 110

C++ Virtualization Programming Latency 110

Brendan Gregg

OCTOBER 7, 2018

Screenshot: tracing read latency for PID 181: # bpftrace -e 'kprobe:vfs_read /pid == 30153/ { @start[tid] = nsecs; } kretprobe:vfs_read /@start[tid]/ { @ns = hist(nsecs - @start[tid]); delete(@start[tid]); }'. Hit Ctrl-C to end.n"); } self int last[dev_t]; /* * Process io start */ io:genunix::start /self->last[args[0]->b_edev] !=

C++ 40

C++ Virtualization Programming Latency 40

SQL Server According to Bob

JANUARY 11, 2020

The caching of data pages and grouping of log records helps remove much, if not all, of the command latency associated with a write operation. In versions ​​ earlier than ​​ SQL Server 2004 SP4, SQL Server latch enforcement protection involved more protection transitions.

Servers 40

Servers Cache Database Media 40