os/bluestore: _dump_onode() don't prolongate Onode anymore. #19841
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Before the patch `BlueStore::_dump_onode()` takes `OnodeRef`
by value effectively extending the object's life time.
This is unnecessary and can be costly as `BlueStore::OnodeRef`
is ref-counted with `boost::intrusive_ptr`. Moreover, callers
are supposed to already hold a reference, so the optimization
for `count == 0` case stays without effect of inhibiting call
to `BlueStore::Onode::put()` and atomic integer increment.
```
0000000000907d70 <BlueStore::_do_read(BlueStore::Collection*, boost::intrusive_ptr<BlueStore::Onode>, unsigned long, unsigned long, ceph::buffer::list&, unsigned int)>:
907d70: 41 57 push %r15
907d72: 41 56 push %r14
...
907f1f: 48 8b 44 24 78 mov 0x78(%rsp),%rax
907f24: 48 8b 00 mov (%rax),%rax
907f27: 48 85 c0 test %rax,%rax
907f2a: 48 89 84 24 a0 01 00 mov %rax,0x1a0(%rsp)
907f31: 00
907f32: 74 04 je 907f38 <BlueStore::_do_read(BlueStore::Collection*, boost::intrusive_ptr<BlueStore::Onode>, unsigned long, unsigned long, ceph::buffer::list&, unsigned int)+0x1c8>
907f34: f0 83 00 01 lock addl $0x1,(%rax)
907f38: 48 8d 84 24 a0 01 00 lea 0x1a0(%rsp),%rax
907f3f: 00
907f40: ba 1e 00 00 00 mov $0x1e,%edx
907f45: 4c 89 ff mov %r15,%rdi
907f48: 48 89 c6 mov %rax,%rsi
907f4b: 48 89 44 24 20 mov %rax,0x20(%rsp)
907f50: e8 9b bc fb ff callq 8c3bf0 <BlueStore::_dump_onode(boost::intrusive_ptr<BlueStore::Onode>, int)>
907f55: 48 8b bc 24 a0 01 00 mov 0x1a0(%rsp),%rdi
907f5c: 00
907f5d: 48 85 ff test %rdi,%rdi
907f60: 74 05 je 907f67 <BlueStore::_do_read(BlueStore::Collection*, boost::intrusive_ptr<BlueStore::Onode>, unsigned long, unsigned long, ceph::buffer::list&, unsigned int)+0x1f7>
907f62: e8 99 14 02 00 callq 929400 <BlueStore::Onode::put()>
907f67: 48 8d 84 24 d0 00 00 lea 0xd0(%rsp),%rax
```
Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>
liewegas
approved these changes
Jan 8, 2018
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Before the patch
BlueStore::_dump_onode()takesOnodeRefby value effectively extending the object's life time.This is unnecessary and can be costly as
BlueStore::OnodeRefis ref-counted withboost::intrusive_ptr. Moreover, callers are supposed to already hold a reference, so the optimization forcount == 0case stays without effect of inhibiting call toBlueStore::Onode::put()and atomic integer increment.Signed-off-by: Radoslaw Zarzynski rzarzyns@redhat.com