Bug 121129

Summary: NetworkProcess can hit the dispatch thread limit
Product: WebKit Reporter: Brady Eidson <beidson>
Component: WebKit2Assignee: Brady Eidson <beidson>
Status: ASSIGNED    
Severity: Normal CC: andersca, ap, sam
Priority: P2 Keywords: InRadar
Version: 528+ (Nightly build)   
Hardware: Mac   
OS: All   
Attachments:
Description Flags
Patch v1 ap: review+

Brady Eidson
Reported 2013-09-10 15:32:27 PDT
NetworkProcess can hit the dispatch thread limit. With certain usage patterns we can have 64+ dispatch threads going, and this can hang the network process into an unrecoverable state. Instead of using a singleton dispatch queue with a high limit, we should use individual queues per-connection with a width of 1. In radar as <rdar://problem/13913483>
Attachments
Patch v1 (4.08 KB, patch)
2013-09-10 15:37 PDT, Brady Eidson 		ap: review+
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Brady Eidson
Comment 1 2013-09-10 15:37:10 PDT
Created attachment 211255 [details] Patch v1 Way too many variables on reproducing this so it's impossible to have a test for. That said, all tests pass locally and "Basic Browsing Seems To Work™"
Geoffrey Garen
Comment 2 2013-09-10 15:49:52 PDT
Comment on attachment 211255 [details] Patch v1 The code here looks right to me. But why does more queues avoid the dispatch thread limit?
Brady Eidson
Comment 3 2013-09-10 15:56:32 PDT
(In reply to comment #2) > (From update of attachment 211255 [details]) > The code here looks right to me. > > But why does more queues avoid the dispatch thread limit? Following up with Geoff IRL.
Sam Weinig
Comment 4 2013-09-10 16:02:45 PDT
(In reply to comment #3) > (In reply to comment #2) > > (From update of attachment 211255 [details] [details]) > > The code here looks right to me. > > > > But why does more queues avoid the dispatch thread limit? > > Following up with Geoff IRL. Will you tell us the answer as well?
Brady Eidson
Comment 5 2013-09-10 16:03:57 PDT
(In reply to comment #4) > (In reply to comment #3) > > (In reply to comment #2) > > > (From update of attachment 211255 [details] [details] [details]) > > > The code here looks right to me. > > > > > > But why does more queues avoid the dispatch thread limit? > > > > Following up with Geoff IRL. > > Will you tell us the answer as well? Following up with Sam IRL also.
Anders Carlsson
Comment 6 2013-09-10 16:09:39 PDT
(In reply to comment #5) > (In reply to comment #4) > > (In reply to comment #3) > > > (In reply to comment #2) > > > > (From update of attachment 211255 [details] [details] [details] [details]) > > > > The code here looks right to me. > > > > > > > > But why does more queues avoid the dispatch thread limit? > > > > > > Following up with Geoff IRL. > > > > Will you tell us the answer as well? > > Following up with Sam IRL also. If possible, it would be nice to have this stored in the bug for future reference. If it’s not possible, please comment in the radar.
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