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RE: What on Earth is JFFS2 GC doing?




>> [root@xxxxxxx.profilesnap-5 -m
>> /boot/linux-2.4.1-JFFS2.System.map
>>      4 startup_32                                 0.0127
>>      1 printk                                     0.0024
>>      1 get_unused_buffer_head                     0.0069
>>      2 write_profile                              0.0417
>>      3 cfi_amdstd_erase_onesize                   0.0031
>>      3 physmap_read32                             0.0938
>>      2 __generic_copy_to_user                     0.0312
>>      1 __generic_copy_from_user                   0.0156
>>     17 total                                      0.0000

>Am I interpreting the above correctly? During the 22.9-second period it 
>took to perform that write, there were a total of 17 timer ticks?

That's what the profile says! I haven't touched my program. Something caused
the ticks to go way down (from ~220+) to the ~17, but the block time still
has not come down? What's taking the rest of the time? I take it that each
"tick" is the kernel 10ms tick?

If so, that's just 170 ms, where is the rest of the time?

>I did expect the worst case times to get a lot better though - 22
>seconds is
>better than 60.

It never was 60. The 60 number came when I turned verbose debug on. I have
never seem more than ~18 secs with debug turned off. It was turned off this
time- so the 22 is the worst we have ever seen till now, but the ticks is
down quite a bit.

Mystery!

Vipin

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