pdsouza

main(_,b,o,g,O){char s[]="@\r$rjre#|dgkwule#|ssdKjj&LOL";if(_^'*'>>1)main(-~_,_,~_,_,-~_);putchar(_--[s]-~0xFC);}

pdsouza

import java.util.concurrent.atomic.AtomicInteger;

/**
 * Simple thread contention microbenchmark consisting of
 * concurrently updating a shared counter a bunch of times.
 *
 * Synchronization strategies used:
 *      (1) intrinsic monitor lock
 *      (2) compare-and-swap atomic instruction via AtomicInteger
 */

pdsouza

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Version: GnuPG v1

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pdsouza

Quick reference

Which commits are on branch B, but not on branch A?

$ git log --oneline A..B

Which commits are not reachable from both A and B? (Symmetric difference)

$ git log --oneline A...B

pdsouza

Linux Kernel Debugging

Debugging an Oops

Let's say we have a kernel oops like in maruos/platform_external_lxc#2 (comment). Here's the relevant snippet:

[  289.238687] Unhandled fault: synchronous external abort (0x96000010) at 0xffffff800087a000
[  289.238853] Internal error: : 96000010 [#1] PREEMPT SMP
[ 289.239003] CPU: 0 PID: 4928 Comm: lxc-start Not tainted 3.10.73-g84d48e8-00002-gfb7b9c7 #1

pdsouza

# http://stackoverflow.com/a/7944434/996825

def max_subarray(a)
    sum = [0]
    max, head, tail = sum[0], -1, -1
    cur_head = 0

    (0...a.size).each do |j|
        # base case included below since sum[-1] = sum[0]
        sum[j] = [0, sum[j-1] + a[j]].max