Re: [PATCH] pipe_read: don't wake up the writer if the pipe is still full

From: Oleg Nesterov
Date: Wed Feb 26 2025 - 13:13:53 EST


On 02/26, Sapkal, Swapnil wrote:
>
> >Can you reproduce with "--process" rather than "--threads" ?
> >
> I was able to reproduce the issue with processes also. Total 33 processes
> were sleeping out of which 20 were readers and 13 were writers.

Thanks a lot. I am wondering what makes your machine (or .config?)
special ;) A lot of people and robots tested this patch with these
options.

> The stack trace for main hackbench process is as follows:
>
> [<0>] do_wait+0xb5/0x110

Yes, this is clear, the main thread/process is not interesting.

> I am trying to reproduce the issue with suggestions by Mateusz.

Great.

So far I still have no clue. Most probably I will ask you to do
more testing after that, perhaps with some debugging patches.

Thanks again for your help,

Oleg.