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Peter Anvin" , "Alexander Gordeev" , "Vincenzo Frascino" , linux-s390@vger.kernel.org, x86@kernel.org, "Aneesh Kumar K.V" , "Ingo Molnar" , "Naveen N. Rao" , "Christian Borntraeger" , "Vasily Gorbik" , "Heiko Carstens" , "Nicholas Piggin" , "Borislav Petkov" , "Andy Lutomirski" , "Bjorn Helgaas" , "Anna-Maria Gleixner" , "Stephen Boyd" , "Randy Dunlap" , linux-kernel@vger.kernel.org, "Sven Schnelle" , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH V2 00/19] timekeeping: Handle potential multiplication overflow Content-Type: text/plain On Mon, Mar 25, 2024, at 07:40, Adrian Hunter wrote: > > Extend the facility also to VDSO, dependent on new config option > GENERIC_VDSO_OVERFLOW_PROTECT which is selected by x86 only, so other > architectures are not affected. The result is a calculation that has > similar performance as before. Most machines showed performance benefit, > except Skylake-based hardware such as Intel Kaby Lake which was seen <1% > worse. I've read through the series, and this pretty much all makes sense, nice work! There are a few patches that just rearrange the local variable declarations to save a few lines, and I don't see those as an improvement, but they also don't hurt aside from distracting slightly from the real changes. Arnd