Re: RE: RE: Memory performance / Cache problem
Mem clock is both times 166MHz. I don't know whether are differences in cycle access and timing, but memclock is fine. Following Siarhei hints of initialize the buffers (around 1.2 MByte each) I get different results in 22kernel for use of malloc alone memcpy = 473.764, loop4 = 448.430, loop1 = 102.770, rand =29.641 calloc alone memcpy = 405.947, loop4 = 361.550, loop1 =95.441, rand =21.853 malloc+memset: memcpy = 239.294, loop4 = 188.617, loop1 =80.871, rand = 4.726 In 31kernel all 3 measures are about the same (unfortunatly low) level of malloc+memset in 22. First of all: What performance can be expected? Does 22 make failures if it is so much faster? Can the later kernels get a boost in memory handling? I used a standard memcpy (think this is glib and hence not neonbased)? To be neonbased I guess it has to be recompiled? How can I find out that neon and cache settings are ok? Using a Omap3530 on EVM board Unfortunatly I don't have a Lauterbach, just a Spectrum Digital which works only until Linux kernel is booting. Best regards Steffen Original-Nachricht Datum: Wed, 14 Oct 2009 08:59:05 -0500 Von: Woodruff, Richard r-woodru...@ti.com An: e...@gmx.de e...@gmx.de, Premi, Sanjeev pr...@ti.com, linux-omap@vger.kernel.org linux-omap@vger.kernel.org Betreff: RE: RE: Memory performance / Cache problem There is no newer u-boot from TI available. There is a SDK 02.01.03.11 but it contains the same uboot 2008.10 with the only addition of the second generation of EVM boards with another network chip. So I checked the uboot from git, but this doesn't support Microns NAND Flash anymore. It is just working with ONENAND. I found a patch which shows the L2 Cache status while kernel boot and implemented it : L2 Cache seems to be already enabled - so this is not the reason. So any other ideas? Are you confident your memory bus isn't running at 1/2 speed? I recall there was a couple day window during wtbu kernel upgrades where memory bus speed with pm was running 1/2 speed after kernel started up. This was somewhat a side effect of constraints frame work and a regression in forward porting. It seems unlikely psp kernel would have shipped with this bug but its something to check. This would match your results. If your memcpy() is neon based then I might be worried about l1neon-caching effects along with factors of (exlcusive-l1-l2-read-allocate cache + pld not being effective on l1 only l2). Which memcpy test are you using? Something in lmbench or just one you wrote. Generally results are a little hard to interpret with exclusive cache behavior in 3430's r1px core. 3630's r3p2 core gives more traditional results as exclusive feature has been removed by arm. If you have the ability using Lauterbach + per file will allow internal space dump which will show all critical parameters during test. It's a 1 minute check for someone who has done it before to ensure the few parameters needed are in line. I can send an example off line of how to do capture. I won't have time to expand on all relevant parameters. Regards, Richard W. -- Neu: GMX DSL bis 50.000 kBit/s und 200,- Euro Startguthaben! http://portal.gmx.net/de/go/dsl02 -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: RE: RE: Memory performance / Cache problem
From: e...@gmx.de [mailto:e...@gmx.de] Sent: Wednesday, October 14, 2009 9:49 AM To: Woodruff, Richard; linux-omap@vger.kernel.org; Premi, Sanjeev Subject: Re: RE: RE: Memory performance / Cache problem Mem clock is both times 166MHz. I don't know whether are differences in cycle access and timing, but memclock is fine. How did you physically verify this? Following Siarhei hints of initialize the buffers (around 1.2 MByte each) I get different results in 22kernel for use of malloc alone memcpy = 473.764, loop4 = 448.430, loop1 = 102.770, rand =29.641 calloc alone memcpy = 405.947, loop4 = 361.550, loop1 =95.441, rand =21.853 malloc+memset: memcpy = 239.294, loop4 = 188.617, loop1 =80.871, rand = 4.726 In 31kernel all 3 measures are about the same (unfortunatly low) level of malloc+memset in 22. Yes aligned buffers can make a difference. But probably more so for small copies. Of course you must touch the memory or mprotect() it so its faulted in, but indications are you have done this. I used a standard memcpy (think this is glib and hence not neonbased)? To be neonbased I guess it has to be recompiled? The version of glibc in use can make a difference. CodeSourcery in 2009 release added PLD's to mem operations. This can give a good benefit. It might be you have optimized library in one case and a non-optimized in another. Regards, Richard W. -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: RE: RE: RE: Memory performance / Cache problem
Mem clock is both times 166MHz. I don't know whether are differences in cycle access and timing, but memclock is fine. How did you physically verify this? Oszi show 166MHz, also the kernel message about freq are in both kernels the same. Following Siarhei hints of initialize the buffers (around 1.2 MByte each) I get different results in 22kernel for use of malloc alone memcpy = 473.764, loop4 = 448.430, loop1 = 102.770, rand = 29.641 calloc alone memcpy = 405.947, loop4 = 361.550, loop1 =95.441, rand = 21.853 malloc+memset: memcpy = 239.294, loop4 = 188.617, loop1 =80.871, rand = 4.726 In 31kernel all 3 measures are about the same (unfortunatly low) level of malloc+memset in 22. Yes aligned buffers can make a difference. But probably more so for small copies. Of course you must touch the memory or mprotect() it so its faulted in, but indications are you have done this. Mh, alignment (to an address) is done with malloc already. Probably you mean something different. I don't understand the difference. For me is malloc+memset=calloc. I'll send you the benchmark code, if you like. I used a standard memcpy (think this is glib and hence not neonbased)? To be neonbased I guess it has to be recompiled? The version of glibc in use can make a difference. CodeSourcery in 2009 release added PLD's to mem operations. This can give a good benefit. It might be you have optimized library in one case and a non-optimized in another. In both kernels I used the same rootfs (via NFS). Indeed I used CS2009q1 and its libs, but we are talking about factor 2..6. This must be something serious. What is your feeling? Does the 22 something strange or are the newer kernels slower that they have to be. Would be interesting to see results on other Omap3 boards with both old an new kernels. Best regards Steffen -- GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT! Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01 -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: RE: RE: RE: Memory performance / Cache problem
From: e...@gmx.de [mailto:e...@gmx.de] Sent: Wednesday, October 14, 2009 12:23 PM To: Woodruff, Richard; Premi, Sanjeev; linux-omap@vger.kernel.org Subject: Re: RE: RE: RE: Memory performance / Cache problem Yes aligned buffers can make a difference. But probably more so for small copies. Of course you must touch the memory or mprotect() it so its faulted in, but indications are you have done this. Mh, alignment (to an address) is done with malloc already. Probably you mean something different. I don't understand the difference. For me is malloc+memset=calloc. I'll send you the benchmark code, if you like. Ok, if it compiles I could try on sdp3430 or sdp3630. Alignment to a cache line is always best. This is 64 bytes in A8. Better yet, being 4K aligned is a good thing to reduce MMU effects. In both kernels I used the same rootfs (via NFS). Indeed I used CS2009q1 and its libs, but we are talking about factor 2..6. This must be something serious. 2009 pay version has optimized thrumb2 and arm mode libraries you download separately. I don't recall if free/lite version integrated this. What is your feeling? Does the 22 something strange or are the newer kernels slower that they have to be. There are a lot of differences between 22 kernel and current ones. First things I'd check would be around MMU settings, special ARM cp15 memory control regs, then omap memory and clock settings. Also some bad device could undercut you. Always good to cat /proc/interrupts and make sure something isn't spewing. Would be interesting to see results on other Omap3 boards with both old an new kernels. I've not noticed anything on sdp on somewhat recent kernels. Regards, Richard W. -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
