| 7086ad6919feb2415c6027163f5c63323bcca27c |
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20-Jun-2014 |
Elliott Hughes <enh@google.com> |
Cache getpid.
In practice, with this implementation we never need to make a system call.
We get the main thread's tid (which is the same as our pid) back from
the set_tid_address system call we have to make during initialization.
A new pthread will have the same pid as its parent, and a fork child's
main (and only) thread will have a pid equal to its tid, which we get for
free from the kernel before clone returns.
The only time we'd actually have to make a getpid system call now is if
we take a signal during fork and the signal handler calls getpid. (That,
or we call getpid in the dynamic linker while it's still dealing with its
own relocations and hasn't even set up the main thread yet.)
Bug: 15387103
Change-Id: I6d4718ed0a5c912fc75b5f738c49a023dbed5189
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| b27a840f4b520bfa095db99b0a2e5205634b0003 |
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11-Jun-2014 |
Elliott Hughes <enh@google.com> |
Add __pure2 to a few more functions, most notably gettid and pthread_self.
Change-Id: I7eee9f26f45130038af09d8285782b07f70a996f
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| 7634db5a0657129225869c3650a992f9cbe82fe4 |
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10-Jun-2014 |
Elliott Hughes <enh@google.com> |
Add a couple more system call benchmarks.
Bug: 15387103
Change-Id: I13419ddf77d201fdbde4c784259c0cb0dcfb9a77
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| 5d9a7ba0dc9c24ed4e4efa9cac0e796fd524b308 |
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31-May-2014 |
Elliott Hughes <enh@google.com> |
Avoid a system call in 'gettid'.
System calls can be pretty slow. This is mako, which has one of our
lowest latencies:
iterations ns/op
BM_unistd_getpid 10000000 209
BM_unistd_gettid 200000000 8
Bug: 15297299 (kernel panic from too many gettid calls)
Bug: 15315766 (excessive gettid overhead in liblogd)
Change-Id: I49656c0fc5b5d092390264a59e4f2c0d8a8b1aeb
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| b28e490b7350b21c5ae9e5b3bb3e082d8357a1b0 |
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11-Mar-2014 |
Elliott Hughes <enh@google.com> |
Add various benchmarks.
These are based on ones from system/extras/tests/bionic/.
Change-Id: I7b1ae15a2ca5d1031a6a511d97b88125c1770047
|