similar to: [LLVMdev] Should LLVM JIT default to lazy or non-lazy?

On Wed, Oct 28, 2009 at 9:50 AM, Chris Lattner <clattner at apple.com> wrote: > > On Oct 28, 2009, at 9:41 AM, Jeffrey Yasskin wrote: > >> In r85295, in response to the discussion at http://llvm.org/PR5184 >> (Lazy JIT ain't thread-safe), I changed the default JIT from lazy to >> non-lazy. It has since come to my attention that this may have been >> the

>From where I sit, this boils down to a very simple question (modulo Chris's point): Either choice will surprise some users. Which surprise is worse? Personally, I'd always prefer correct but slow behavior by default, and explicitly enabling dangerous (but in some cases fast) behavior. I would also point out that it seems that most of the people new to the JIT are surprised by the

I have no objection to Chris' proposal. Evan On Oct 29, 2009, at 9:45 AM, Jeffrey Yasskin wrote: > Are you objecting to Chris's proposal? I was waiting to implement it > until you replied so I wouldn't have to implement two things. I > disagree with a lot of what you wrote below, but it's not worth > arguing about if there's a compromise we can both live with.

There is nothing here that prevents users from enabling or disabling lazy JIT. We're talk about flipping the default behavior. That does not make the API any better or worse. Nor does it fix the inherent thread safety issue. I can tell you there are no Apple clients that depend on the lazy JIT. Please do not imply I am being secretive. I am simply busy. My objection is simple.

Cool, I'll start implementing it. Thanks all for the decision! On Thu, Oct 29, 2009 at 11:03 AM, Evan Cheng <evan.cheng at apple.com> wrote: > I have no objection to Chris' proposal. > > Evan > > On Oct 29, 2009, at 9:45 AM, Jeffrey Yasskin wrote: > >> Are you objecting to Chris's proposal? I was waiting to implement it >> until you replied so I

On Oct 28, 2009, at 9:41 AM, Jeffrey Yasskin wrote: > In r85295, in response to the discussion at http://llvm.org/PR5184 > (Lazy JIT ain't thread-safe), I changed the default JIT from lazy to > non-lazy. It has since come to my attention that this may have been > the wrong change, so I wanted to ask you guys. > > A couple reasons to make the default non-lazy compilation:

On Oct 28, 2009, at 10:07 AM, Chandler Carruth wrote: > From where I sit, this boils down to a very simple question (modulo > Chris's point): Either choice will surprise some users. Which surprise > is worse? Personally, I'd always prefer correct but slow behavior by > default, and explicitly enabling dangerous (but in some cases fast) > behavior. The behavior is only

On Wed, Oct 28, 2009 at 12:21 PM, Evan Cheng <evan.cheng at apple.com> wrote: > > On Oct 28, 2009, at 10:07 AM, Chandler Carruth wrote: > >> From where I sit, this boils down to a very simple question (modulo >> Chris's point): Either choice will surprise some users. Which surprise >> is worse? Personally, I'd always prefer correct but slow behavior by

Are you objecting to Chris's proposal? I was waiting to implement it until you replied so I wouldn't have to implement two things. I disagree with a lot of what you wrote below, but it's not worth arguing about if there's a compromise we can both live with. On Thu, Oct 29, 2009 at 12:36 AM, Evan Cheng <evan.cheng at apple.com> wrote: > There is nothing here that prevents

A possible patch implementing this is at http://codereview.appspot.com/144074 (http://codereview.appspot.com/download/issue144074_1.diff). I do NOT think we should accept this patch: It changes a lot of APIs and makes users specify the choice in many places, while I think most users really just want one choice for their whole app. There's a good argument to be made that users may want to

Hi Jeffrey, Jeffrey Yasskin wrote: > Cool, I'll start implementing it. > Great! Thanks. Just to clarify things: on my end, it doesn't really matter what is the default behavior, as long as vmkit can continue to have the existing behavior of lazy compilation. With Chris' solution, I was wondering how you would implement the getPointerToFunction{Eager, Lazy} functions when

On Thu, Oct 29, 2009 at 2:30 PM, Nicolas Geoffray <nicolas.geoffray at lip6.fr> wrote: > Hi Jeffrey, > > Jeffrey Yasskin wrote: >> >> Cool, I'll start implementing it. >> > > Great! Thanks. > > Just to clarify things: on my end, it doesn't really matter what is the > default behavior, as long as vmkit can continue to have the existing >

On Wed, Oct 28, 2009 at 9:57 AM, Jeffrey Yasskin <jyasskin at google.com> wrote: > On Wed, Oct 28, 2009 at 9:50 AM, Chris Lattner <clattner at apple.com> wrote: >> >> On Oct 28, 2009, at 9:41 AM, Jeffrey Yasskin wrote: >> >>> In r85295, in response to the discussion at http://llvm.org/PR5184 >>> (Lazy JIT ain't thread-safe), I changed the

On Wed, Oct 28, 2009 at 11:41 AM, Jeffrey Yasskin <jyasskin at google.com> wrote: > And a couple to default to lazy compilation: > * It's safe for single-threaded code. > * There are existing users who have assumed this default. And what might break if this assumption doesn't hold?

Thanks Jeffrey ! If possible, keep me inform (on revision number), I'm interested to see how you will do the unit test. (For my future patch... :) ). Thanks again. Olivier. On Wed, Feb 10, 2010 at 6:22 PM, Jeffrey Yasskin <jyasskin at google.com>wrote: > Thanks for the patch! I'll clean this up, convert your sample to a > unit test, and commit it for 2.7. > > On Sun,

On 2009-10-29 23:55, Jeffrey Yasskin wrote: > On Thu, Oct 29, 2009 at 2:30 PM, Nicolas Geoffray > <nicolas.geoffray at lip6.fr> wrote: > >> Hi Jeffrey, >> >> Jeffrey Yasskin wrote: >> >>> Cool, I'll start implementing it. >>> >>> >> Great! Thanks. >> >> Just to clarify things: on my end, it

Hi Jeffrey, Thanks for pointing me in the right direction ! I'm not using the JIT in lazy mode, but it was fun to understand the lazy-stub code. Attached you will find a patch which follow your 1st option : a map Stub_address -> JITResolver instance, except that the used map is a "std::map" to apply the same upper_bound trick as in the map CallSiteToFunctionMap of the

On 2009-11-01 08:40, Jeffrey Yasskin wrote: > 2009/10/30 Török Edwin <edwintorok at gmail.com>: > >> On 2009-10-29 23:55, Jeffrey Yasskin wrote: >> >>> On Thu, Oct 29, 2009 at 2:30 PM, Nicolas Geoffray >>> <nicolas.geoffray at lip6.fr> wrote: >>> >>> >>>> Hi Jeffrey, >>>> >>>>

Thanks for the patch! I'll clean this up, convert your sample to a unit test, and commit it for 2.7. On Sun, Feb 7, 2010 at 6:09 AM, Olivier Meurant <meurant.olivier at gmail.com> wrote: > Hi Jeffrey, > > Thanks for pointing me in the right direction ! > I'm not using the JIT in lazy mode, but it was fun to understand the > lazy-stub code. > > Attached you will

2009/10/30 Török Edwin <edwintorok at gmail.com>: > On 2009-10-29 23:55, Jeffrey Yasskin wrote: >> On Thu, Oct 29, 2009 at 2:30 PM, Nicolas Geoffray >> <nicolas.geoffray at lip6.fr> wrote: >> >>> Hi Jeffrey, >>> >>> Jeffrey Yasskin wrote: >>> >>>> Cool, I'll start implementing it. >>>> >>>>