x86: Add optimized popcnt variants
in [Kernel]
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From: Borislav Petkov on 9 Mar 2010 11:30 From: Peter Zijlstra <peterz(a)infradead.org> Date: Tue, Mar 09, 2010 at 04:50:40PM +0100 > Should all be fine as it is, that patch > ( http://lkml.org/lkml/2010/2/4/119 ) is against a kernel with fce877e3 > in, I've just checked and it still applies to tip/master as of this > writing (although it grew a single 2 line offset for 1 hunk). Well, this way, I'm getting .... In file included from include/linux/kernel.h:15, from /home/linux-2.6/arch/x86/include/asm/percpu.h:45, from /home/linux-2.6/arch/x86/include/asm/current.h:5, from /home/linux-2.6/arch/x86/include/asm/processor.h:15, from /home/linux-2.6/arch/x86/include/asm/atomic.h:6, from include/linux/crypto.h:20, from arch/x86/kernel/asm-offsets_64.c:8, from arch/x86/kernel/asm-offsets.c:4: include/linux/bitops.h:52:1: warning: "HWEIGHT8" redefined .... due to the fact that we have multiple definitions of HWEIGHT*: The one batch is in <include/linux/bitops.h> introduced by fce877e3. The other is in <include/asm-generic/bitops/const_hweight.h> which is pulled in into <include/linux/bitops.h> through "#include <asm/bitops.h>", which, in turn, <includes asm/arch_hweight.h> and <include/asm-generic/bitops/const_hweight.h>. The obvious resolution is to remove the HWEIGHT* batch from <include/asm-generic/bitops/const_hweight.h> since they're functionally identical with the ones in <include/linux/bitops.h>, no? -- Regards/Gruss, Boris. - Advanced Micro Devices, Inc. Operating Systems Research Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Peter Zijlstra on 9 Mar 2010 11:40 On Tue, 2010-03-09 at 17:23 +0100, Borislav Petkov wrote: > From: Peter Zijlstra <peterz(a)infradead.org> > Date: Tue, Mar 09, 2010 at 04:50:40PM +0100 > > > Should all be fine as it is, that patch > > ( http://lkml.org/lkml/2010/2/4/119 ) is against a kernel with fce877e3 > > in, I've just checked and it still applies to tip/master as of this > > writing (although it grew a single 2 line offset for 1 hunk). > > Well, this way, I'm getting > > ... > In file included from include/linux/kernel.h:15, > from /home/linux-2.6/arch/x86/include/asm/percpu.h:45, > from /home/linux-2.6/arch/x86/include/asm/current.h:5, > from /home/linux-2.6/arch/x86/include/asm/processor.h:15, > from /home/linux-2.6/arch/x86/include/asm/atomic.h:6, > from include/linux/crypto.h:20, > from arch/x86/kernel/asm-offsets_64.c:8, > from arch/x86/kernel/asm-offsets.c:4: > include/linux/bitops.h:52:1: warning: "HWEIGHT8" redefined > ... > > due to the fact that we have multiple definitions of HWEIGHT*: > > The one batch is in <include/linux/bitops.h> introduced by fce877e3. > > The other is in <include/asm-generic/bitops/const_hweight.h> which > is pulled in into <include/linux/bitops.h> through "#include > <asm/bitops.h>", which, in turn, <includes asm/arch_hweight.h> and > <include/asm-generic/bitops/const_hweight.h>. > > The obvious resolution is to remove the HWEIGHT* batch from > <include/asm-generic/bitops/const_hweight.h> since they're functionally > identical with the ones in <include/linux/bitops.h>, no? I thought the patch did that, see this hunk (straight from http://lkml.org/lkml/2010/2/4/119 ): --- Index: linux-2.6/include/linux/bitops.h =================================================================== --- linux-2.6.orig/include/linux/bitops.h +++ linux-2.6/include/linux/bitops.h @@ -45,31 +45,6 @@ static inline unsigned long hweight_long return sizeof(w) == 4 ? hweight32(w) : hweight64(w); } -/* - * Clearly slow versions of the hweightN() functions, their benefit is - * of course compile time evaluation of constant arguments. - */ -#define HWEIGHT8(w) \ - ( BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + \ - (!!((w) & (1ULL << 0))) + \ - (!!((w) & (1ULL << 1))) + \ - (!!((w) & (1ULL << 2))) + \ - (!!((w) & (1ULL << 3))) + \ - (!!((w) & (1ULL << 4))) + \ - (!!((w) & (1ULL << 5))) + \ - (!!((w) & (1ULL << 6))) + \ - (!!((w) & (1ULL << 7))) ) - -#define HWEIGHT16(w) (HWEIGHT8(w) + HWEIGHT8((w) >> 8)) -#define HWEIGHT32(w) (HWEIGHT16(w) + HWEIGHT16((w) >> 16)) -#define HWEIGHT64(w) (HWEIGHT32(w) + HWEIGHT32((w) >> 32)) - -/* - * Type invariant version that simply casts things to the - * largest type. - */ -#define HWEIGHT(w) HWEIGHT64((u64)(w)) - /** * rol32 - rotate a 32-bit value left * @word: value to rotate -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Peter Zijlstra on 9 Mar 2010 12:40 On Tue, 2010-03-09 at 18:32 +0100, Borislav Petkov wrote: > From: Peter Zijlstra <peterz(a)infradead.org> > Date: Tue, Mar 09, 2010 at 05:32:49PM +0100 > > > I thought the patch did that, see this hunk (straight from > > http://lkml.org/lkml/2010/2/4/119 ): > > Bollocks, I seem to have lost that hunk while applying the patch by > foot, sorry for the noise. > > By the way, I can't seem to find your patch in Andrew's tree, is it > still going through his tree? I hope so, Andrew, need me to resend or do you still have a copy? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Borislav Petkov on 9 Mar 2010 12:40 From: Peter Zijlstra <peterz(a)infradead.org> Date: Tue, Mar 09, 2010 at 05:32:49PM +0100 > I thought the patch did that, see this hunk (straight from > http://lkml.org/lkml/2010/2/4/119 ): Bollocks, I seem to have lost that hunk while applying the patch by foot, sorry for the noise. By the way, I can't seem to find your patch in Andrew's tree, is it still going through his tree? -- Regards/Gruss, Boris. - Advanced Micro Devices, Inc. Operating Systems Research Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Borislav Petkov on 18 Mar 2010 07:20
From: "H. Peter Anvin" <hpa(a)zytor.com> Date: Sat, Feb 27, 2010 at 12:00:26PM -0800 > On 02/27/2010 12:28 AM, Borislav Petkov wrote: > > > >> I guess, on the other hand, if it ends up not getting merged until .35 > >> it's not a huge deal either. > > > > Yeah, let's give it another round of testing and queue it for .35 - > > AFAIR Ingo runs also a wide testing effort so it spending another cycle > > in -tip and being hammered on by us could give us a bit more certainty. > > > > Yes, if we can get into -tip then we'll get more test coverage, so I'll > queue it up for .35 as soon as the merge window closes. Please remind > me if I forget. Ok, I've been pretty busy lately and this got pushed back on the todo list. I finally got around to do some build-testing with a bunch of compilers and -fcall-saved* seem to get accepted. I haven't stared at their asm output though, yet: command: make CC=gcc-<version> HOSTCC=gcc-<version> -j4 compile stats (64bit only): not ok: - gcc-3.3 (GCC) 3.3.5 (Debian 1:3.3.5-13): OOM KILLER goes off, gcc-3.3 leak maybe ok: - gcc-3.4 (GCC) 3.4.4 20050314 (prerelease) (Debian 3.4.3-13sarge1) - gcc-4.1 (GCC) 4.1.3 20080704 (prerelease) (Debian 4.1.2-27) - gcc-4.3 (Debian 4.3.4-6) 4.3.4 - gcc (Debian 4.4.2-6) 4.4.2 - gcc (Debian 4.4.3-3) 4.4.3 - gcc-3.4.6 (GCC) 3.4.6 (Gentoo 3.4.6-r2 p1.6, ssp-3.4.6-1.0, pie-8.7.10) - gcc-4.1.2 (GCC) 4.1.2 (Gentoo 4.1.2 p1.3) I'm attaching the versions of the patches I'm using. The first one by PeterZ touches a bunch of arches and Andrew hasn't picked it up yet so the question of getting the second (popcnt) patch to see wider testing in some tree is still unresolved. Suggestions, ideas? Thanks. -- Regards/Gruss, Boris. -- Advanced Micro Devices, Inc. Operating Systems Research Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |