Lewis Chan

something wrong with compile.sh

1

Hi. I see this article https://johnnysswlab.com/faster-hash-maps-binary-trees-etc-through-data-layout-modification/ and is eager to try the example. But I find that something wrong with https://github.com/ibogosavljevic/johnysswlab/blob/master/2023-09-datastucturelayout/compile.sh `clang++ -Werror -DLIKWID_PERFMON -O3 -std=c++17 -Werror -g array_of_pointers.cpp -I...

array_of_pointer example behave wired

2

Hi. I like this article https://johnnysswlab.com/faster-hash-maps-binary-trees-etc-through-data-layout-modification/ I try it by self and find interesting results. compile: `clang++ -DLIKWID_PERFMON -O3 -std=c++17 -g array_of_pointers.cpp -I ../common -fopenmp` On fedora, clang 15 within...

Do you think the word machine is greatly misused ?

1

Hi, calio. I love this cheat sheet. I've learned some concepts from `ragel-guide.pdf`. Somehow I think the word `machine` is misused by the author. Isn't it better to replace it...

empty info when opening web window

1

I run it on x86_64 in virtualbox, but it shows empty. Don't know what's wrong. gcc and other tools are located /usr/bin, so I have to use `--gcc-tools-base` , or...

why pg_lock_tracer need -r whereas lw_lock,row_lock tool don't ?

1

According to README page, I find that only `pg_lock_tracer ` do with `-r` option, whereas the other two don't. I try to remove `-r` from `pg_lock_tracer ` command, and it...

the tool cannot apply on pg process on production server ?

1

> In order to be able to attach the uprobes to the functions, they should not to be optimized away (e.g., inlined) during the compilation of PostgreSQL. Otherwise errors like...

Hi, after reading https://johnnysswlab.com/the-memory-subsystem-from-the-viewpoint-of-software-how-memory-subsystem-effects-software-performance-1-2/ , I feel it's worthy to try by myself. As I run many times, it's not convenient to copy every data into Excel or google charts...