Message 366623 - Python tracker

Message366623

Author	Mark.Shannon
Recipients	Mark.Shannon, carljm, corona10, dino.viehland, eelizondo, gregory.p.smith, nascheme, pablogsal, pitrou, shihai1991, steve.dower, tim.peters, vstinner
Date	2020-04-16.18:41:10
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1587062470.13.0.23341654956.issue40255@roundup.psfhosted.org>
In-reply-to

Content
Do you have more details on your comparison? I'm somewhat puzzled how a version that does no more work and has no jumps is slower. The memory hit is not immediate, but making the object header immutable prevents changes like https://github.com/markshannon/cpython/commit/c73407e7b5d1a0fc794d55c6bcc91cfdc958f6c4 which would potentially save the two word per object overhead that the cyclic GC currently imposes.

Content

Do you have more details on your comparison?
I'm somewhat puzzled how a version that does no more work and has no jumps is slower.

The memory hit is not immediate, but making the object header immutable prevents changes like https://github.com/markshannon/cpython/commit/c73407e7b5d1a0fc794d55c6bcc91cfdc958f6c4
which would potentially save the two word per object overhead that the cyclic GC currently imposes.

History
Date	User	Action	Args
2020-04-16 18:41:10	Mark.Shannon	set	recipients: + Mark.Shannon, tim.peters, nascheme, gregory.p.smith, pitrou, vstinner, carljm, dino.viehland, steve.dower, corona10, pablogsal, eelizondo, shihai1991
2020-04-16 18:41:10	Mark.Shannon	set	messageid: <1587062470.13.0.23341654956.issue40255@roundup.psfhosted.org>
2020-04-16 18:41:10	Mark.Shannon	link	issue40255 messages
2020-04-16 18:41:10	Mark.Shannon	create