RandomAccessFile and the native futex

Hi All

I see 52 ms being spent in calls to readFully() method of the RandomAccessFile. I ran strace against my process and figured that these weren't reads going to disk. All reads were being served from the buffer cache (verified by running iostat). It also looks like the 52 ms is a futex timeout but strace doesn't report which system call causes this. I was wondering if anyone has seen this problem before and how do I go about addressing this? Do I have access to the source code of the native library used by RandomAccessFile? Here is the output from strace (the offending line is in bold):


29673 16:36:47.747658 
futex(0x2aac3f62a674, FUTEX_WAIT, 1, {0, 49972000} <unfinished 
...>
29716 16:36:47.784379 <... futex 
resumed> ) = -1 ETIMEDOUT (Connection timed out) 
<0.044427>
29716 16:36:47.784469 
futex(0x2aac3f66e328, FUTEX_WAKE, 1) = 0 
<0.000012>
29716 16:36:47.784548 
clock_gettime(CLOCK_REALTIME, {1197938207, 784565000}) = 0 
<0.000012>
29716 16:36:47.784610 
futex(0x2aac3f670314, FUTEX_WAIT, 1, {0, 19970000} <unfinished 
...>
29673 16:36:47.799354 <... futex 
resumed> ) = -1 ETIMEDOUT (Connection timed out) 
<0.051676>
29673 16:36:47.799392 
futex(0x2aac3f2a7228, FUTEX_WAKE, 1) = 0 
<0.000011>
29673 16:36:47.799434 
clock_gettime(CLOCK_MONOTONIC, {6497274, 522227024}) = 0 
<0.000007>
29673 16:36:47.799481 
clock_gettime(CLOCK_MONOTONIC, {6497274, 522275024}) = 0 
<0.000007>

Thanks
Avinash

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