Re: What every programmer should know about memory, in 2019?
On Mon, Oct 28, 2019 at 12:13:57AM +1100, Andrew McGlashan wrote: > -BEGIN PGP SIGNED MESSAGE- > Hash: SHA256 > > Hi, > > On 25/10/19 1:22 am, Boyan Penkov wrote: > > Hello, > > > > Ulrich Drepper's piece on on-chip memory architectures is a > > fantastic read, and I recently had the chance to revisit it -- > > https://people.freebsd.org/~lstewart/articles/cpumemory.pdf > > > > I am writing to ask more knowledgeable folks if the last 13 years > > have seen sufficient changes that render parts of this out of date > > or misleading on 2019 hardware. > > Well, I don't have any great insights here, but row hammer, spectre, > meltdown and the like weren't a thing back then were it? I guess they were "technically" possible back then, but not as important as these days... Cheers -- t signature.asc Description: Digital signature
Re: What every programmer should know about memory, in 2019?
On Sun, Oct 27, 2019 at 08:40:33AM -0400, Boyan Penkov wrote: > Thanks, Tomas — any pointers to where I might find such an revised, amended > version? I'd have told you if I knew... Cheers -- t signature.asc Description: Digital signature
Re: What every programmer should know about memory, in 2019?
Andrew McGlashan wrote: > Well, I don't have any great insights here, but row hammer, spectre, > meltdown and the like weren't a thing back then were it? There are > more "modern" day exploits against memory, especially with shared > servers ... you know, those cloud servers that too many people trust ;-) Haha, I was thinking those cloud servers are exploited per default or by itself
Re: What every programmer should know about memory, in 2019?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA256 Hi, On 25/10/19 1:22 am, Boyan Penkov wrote: > Hello, > > Ulrich Drepper's piece on on-chip memory architectures is a > fantastic read, and I recently had the chance to revisit it -- > https://people.freebsd.org/~lstewart/articles/cpumemory.pdf > > I am writing to ask more knowledgeable folks if the last 13 years > have seen sufficient changes that render parts of this out of date > or misleading on 2019 hardware. Well, I don't have any great insights here, but row hammer, spectre, meltdown and the like weren't a thing back then were it? There are more "modern" day exploits against memory, especially with shared servers ... you know, those cloud servers that too many people trust ;-) Cheers A. -BEGIN PGP SIGNATURE- iHUEAREIAB0WIQTJAoMHtC6YydLfjUOoFmvLt+/i+wUCXbWYDgAKCRCoFmvLt+/i ++vIAP9fLpZ0UtWzuLRNYwO8As+6Mhe17evrjCHUm2+Uqmv2NAD9HKQ1U0OhVT22 8+NBfi7qFnm+RWfbmsFZGZuypUR+zCQ= =cjSG -END PGP SIGNATURE-
Re: What every programmer should know about memory, in 2019?
Thanks, Tomas — any pointers to where I might find such an revised, amended version? Cheers! -- Boyan Penkov www.boyanpenkov.com > On Oct 25, 2019, at 03:22, to...@tuxteam.de wrote: > > On Fri, Oct 25, 2019 at 02:11:58AM +0200, deloptes wrote: >> Boyan Penkov wrote: >> >>> Ulrich Drepper's piece on on-chip memory architectures is a fantastic >>> read, and I recently had the chance to revisit it -- >>> https://people.freebsd.org/~lstewart/articles/cpumemory.pdf >>> >>> I am writing to ask more knowledgeable folks if the last 13 years have >>> seen sufficient changes that render parts of this out of date or >>> misleading on 2019 hardware. >> >> 114 pages! Really :) I am not an expert but let me ask you a question - did >> something change in the past 13y regarding memory in context of >> programming? I think no. Only "developers" became dumber. > > Processors have (again) changed a bit: the gap between processor > speed and memory has widened a tad, there are more cores on a > package (putting even more pressure on the memory bottleneck). > > Compilers have become smarter (and more insidious, depending on > your problem at hand) [1] to try to keep that illusion of Moore's > "law" upright. > > So yes, an update on Ulrich Drepper's paper would be welcome. > > A good read, btw. > > Cheers > [1] https://lwn.net/Articles/799218/ > -- tomás
Re: What every programmer should know about memory, in 2019?
On Fri, Oct 25, 2019 at 02:11:58AM +0200, deloptes wrote: > Boyan Penkov wrote: > > > Ulrich Drepper's piece on on-chip memory architectures is a fantastic > > read, and I recently had the chance to revisit it -- > > https://people.freebsd.org/~lstewart/articles/cpumemory.pdf > > > > I am writing to ask more knowledgeable folks if the last 13 years have > > seen sufficient changes that render parts of this out of date or > > misleading on 2019 hardware. > > 114 pages! Really :) I am not an expert but let me ask you a question - did > something change in the past 13y regarding memory in context of > programming? I think no. Only "developers" became dumber. Processors have (again) changed a bit: the gap between processor speed and memory has widened a tad, there are more cores on a package (putting even more pressure on the memory bottleneck). Compilers have become smarter (and more insidious, depending on your problem at hand) [1] to try to keep that illusion of Moore's "law" upright. So yes, an update on Ulrich Drepper's paper would be welcome. A good read, btw. Cheers [1] https://lwn.net/Articles/799218/ -- tomás signature.asc Description: Digital signature
Re: What every programmer should know about memory, in 2019?
Boyan Penkov wrote: > Ulrich Drepper's piece on on-chip memory architectures is a fantastic > read, and I recently had the chance to revisit it -- > https://people.freebsd.org/~lstewart/articles/cpumemory.pdf > > I am writing to ask more knowledgeable folks if the last 13 years have > seen sufficient changes that render parts of this out of date or > misleading on 2019 hardware. 114 pages! Really :) I am not an expert but let me ask you a question - did something change in the past 13y regarding memory in context of programming? I think no. Only "developers" became dumber.
