Re: 2.4.20: Proccess stuck in __lock_page ...

[manish]

Marcelo Tosatti wrote:

>
>On Tue, 27 May 2003, Marc-Christian Petersen wrote:
>
>>On Tuesday 27 May 2003 19:47, Marcelo Tosatti wrote:
>>
>>Hi Marcelo,
>>
>>>>A pause is _not_ perfectly fine, even not to some extent. That pause we
>>>>are discussing about is a pause of the _whole_ machine, not just disk i/o
>>>>pauses. Mouse stops, keyboard stops, everything stops, who knows wtf.
>>>>
>>>Do you also notice them?
>>>
>>I do, people I know do also, numbers of those people only _I_ know are about
>>~30. I've reported this problem over a year ago while 2.4.19-pre time.
>>
>
>Can you please try to reproduce it with -aa?
>
>>>>That behaviour is absolutely bullshit for desktop users. For serverusage
>>>>you may not notice it in this dimension (mostly no X so no mouse), but
>>>>also for a server environment this may be very bad.
>>>>
>>>Agreed.
>>>
Hello !

After several tests, I have noticed that I can produce this problem 
easily when my bdflush settings are:

30   50      32      100     50      300   60       0       0

and it occurs very less frequently when my settings are:

2       50      32      100     50      300     1       0       0

Right now, I noticed the following stack trace for one such stuck process:

sys_read
generic_file_read
do_generic_file_read
page_cache_read
__alloc_pages
balance_classzone
try_to_free_pages
shrink_caches
shrink_cache
try_to_release_page
try_to_free_buffer
sync_page_buffers
wait_on_buffer
__wait_on_buffer
schedule

Thanks
-Manish