search for: mergable

Hi! I'm interested in what attributes in LLVM mean, specifically how to say that the result is always the same for the given input parameters. The main thing would be to merge two calls with the same parameters when the function is declared but not defined. (just like two stores). I'll call this property mergability. %1 := call @test(%0) %2 := call @test(%0) and the optimization would

...the guest that we've got a new packet, we >> >> don't win on latency. We might reduce syscall overhead with a >> >> multi-dimensional readv to read multiple packets at once? >> > >> > Sounds like recvmmsg(2). >> >> Could we map this to mergable rx buffers though? >> >> Regards, >> >> Anthony Liguori > > Yes because we don't have to complete buffers in order. What I meant though was for GRO, we don't know how large the received packet is going to be. Mergable rx buffers lets us allocate a pool of d...

...the guest that we've got a new packet, we >> >> don't win on latency. We might reduce syscall overhead with a >> >> multi-dimensional readv to read multiple packets at once? >> > >> > Sounds like recvmmsg(2). >> >> Could we map this to mergable rx buffers though? >> >> Regards, >> >> Anthony Liguori > > Yes because we don't have to complete buffers in order. What I meant though was for GRO, we don't know how large the received packet is going to be. Mergable rx buffers lets us allocate a pool of d...

...? If we need to >> return to userspace to tell the guest that we've got a new packet, we >> don't win on latency. We might reduce syscall overhead with a >> multi-dimensional readv to read multiple packets at once? > > Sounds like recvmmsg(2). Could we map this to mergable rx buffers though? Regards, Anthony Liguori > > Stefan

...? If we need to >> return to userspace to tell the guest that we've got a new packet, we >> don't win on latency. We might reduce syscall overhead with a >> multi-dimensional readv to read multiple packets at once? > > Sounds like recvmmsg(2). Could we map this to mergable rx buffers though? Regards, Anthony Liguori > > Stefan

...ole bunch of cleanups. It's taken a long road to get here, and I'd like to thank the following people who made this possible: - Steve Hemminger for the initial prodding and extreme patience - Hank Janssen for providing the code and working with me to get it into a workable and semi-mergable state. His involvement within Microsoft was also invaluable. - Sam Ramji for his push within Microsoft to make this happen in a manner that works with the Linux community. - Novell for sponsoring my work on the Linux Driver project, without which, this would not have even been poss...

...ole bunch of cleanups. It's taken a long road to get here, and I'd like to thank the following people who made this possible: - Steve Hemminger for the initial prodding and extreme patience - Hank Janssen for providing the code and working with me to get it into a workable and semi-mergable state. His involvement within Microsoft was also invaluable. - Sam Ramji for his push within Microsoft to make this happen in a manner that works with the Linux community. - Novell for sponsoring my work on the Linux Driver project, without which, this would not have even been poss...

Hello, Tatu > Is that correct? I think it's just something to be aware of. Currently we're aggressively merging globals by default. Do you think it will be better to provide special flag to control this behavior? -- WBR, Anton Korobeynikov

...ently we're aggressively merging globals by default. Do you > think it > will be better to provide special flag to control this behavior? Please no flag. If we want to fix this problem, lets do it right. To me this consists of some flag on GlobalVariable that says that it is 'mergable' or something like that. Then -constmerge would be changed to only merge globals with this flag on it, or globals that are provably not "address exposed" (which could be modeled by having the optimizer set the bit). We'd also have to change the code generator to stop sen...

Hi László, On 8/13/20 5:21 PM, László Radnai via llvm-dev wrote: > (Sorry I clicked reply instead of reply to all) > I'm fighting with my email client, I hope the quoted text contains > what I want it to contain. > > ---------- Forwarded message ---------- > From: László Radnai <radlaci97 at gmail.com> > Date: Fri, 14 Aug 2020 00:11:35 +0200 > Subject:

...to mergeable sections in assembly. If we use the conservative definition of mergeable, fix any code that assumes distinct globals don't get merged, like the code that folds equality comparisons between distinct globals to false. Optionally, add a new optimization step which marks constants as mergable when their address isn't taken. -Eli

On 17/10/2008, Chris Lattner <clattner at apple.com> wrote: > Please no flag. If we want to fix this problem, lets do it right. To > me this consists of some flag on GlobalVariable that says that it is > 'mergable' or something like that. Wouldn't it be slightly cleaner to mark the distinct objects in the LLVM intermediate representation? This would make the default case the one resulting in best code, and seems to me to follow the principle of structural equivalence of types (and values) used elsew...

...ufficient: It is unspecified whether such a variable has an address distinct from that of any other object in the program to reuse the concept and words from 8.4p8 (n2461). This isn't quite right, but we know what is meant by it. The implementation is free to merge it with any other mergable object. > This has the following effects on current optimizers: constmerge only > merges globals marked mergeable. Only mergeable constants are emitted > into mergeable sections in assembly. If we use the conservative > definition of mergeable, fix any code that assumes distinct glob...

...e past few > releases. I'm slowly winnowing down the api to make it impossible to > get wrong for this type of thing, and am almost there. > > DRM is the big fish left to tackle, I have submitted some patches in the > past, but lots more cleanup needs to be done to get them into mergable > shape. I just need to find the time... Just to avoid duplication, Wambui (cc'ed) just started working on this. Expect a lot more void return values and a pile of deleted code rsn. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch

On 2/9/20 2:55 AM, Greg Kroah-Hartman wrote: > When calling debugfs functions, there is no need to ever check the > return value. The function can work or not, but the code logic should > never do something different based on this. > Should we follow that line of reasoning further, and simply return void from the debugfs functions--rather than playing whack-a-mole with this

On 07/31/2017 02:55 PM, Michal Hocko wrote: > On Mon 31-07-17 12:13:33, Wei Wang wrote: >> Ballooned pages will be marked as MADV_DONTNEED by the hypervisor and >> shouldn't be given to the host ksmd to scan. > Could you point me where this MADV_DONTNEED is done, please? Sure. It's done in the hypervisor when the balloon pages are received. Please see line 40 at

On 07/31/2017 02:55 PM, Michal Hocko wrote: > On Mon 31-07-17 12:13:33, Wei Wang wrote: >> Ballooned pages will be marked as MADV_DONTNEED by the hypervisor and >> shouldn't be given to the host ksmd to scan. > Could you point me where this MADV_DONTNEED is done, please? Sure. It's done in the hypervisor when the balloon pages are received. Please see line 40 at

Olly Betts writes: > On Thu, Dec 29, 2016 at 07:21:41PM +0100, Jean-Francois Dockes wrote: > > Xapian 1.2 supports a query like: > > > > (A OR B) NEAR (C OR D) > > > > and distributes the factors to create something like: > > > > (A NEAR 2 C) OR (B NEAR 2 C) OR (B NEAR 2 C) OR (A NEAR 2 C) > > > > Xapian 1.4 rejects such

...008, at 11:18 AM, danchr at gmail.com wrote: > On 17/10/2008, Chris Lattner <clattner at apple.com> wrote: >> Please no flag. If we want to fix this problem, lets do it right. >> To >> me this consists of some flag on GlobalVariable that says that it is >> 'mergable' or something like that. > > Wouldn't it be slightly cleaner to mark the distinct objects in the > LLVM intermediate representation? That is what I'm suggesting. Each llvm IR global variable would have its own flag. -Chris

.../linux/debugfs.h over the past few releases. I'm slowly winnowing down the api to make it impossible to get wrong for this type of thing, and am almost there. DRM is the big fish left to tackle, I have submitted some patches in the past, but lots more cleanup needs to be done to get them into mergable shape. I just need to find the time... thanks, greg k-h