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McKenney" , Boqun Feng , Wei Liu References: <20250813155941.014821755@linutronix.de> <12342355-b3fb-4e78-ad5b-dcfff1366ccf@kernel.dk> <87bjoi7vqx.ffs@tglx> Content-Language: en-US From: Jens Axboe In-Reply-To: <87bjoi7vqx.ffs@tglx> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/13/25 3:32 PM, Thomas Gleixner wrote: > On Wed, Aug 13 2025 at 11:45, Jens Axboe wrote: >> On 8/13/25 10:29 AM, Thomas Gleixner wrote: >>> >>> suffered badly from the stale eventmask bits and the cleaned up version >>> brought a whopping 25+% performance gain. >> >> Thanks for doing this work, it's been on my list to take a look at rseq >> as it's quite the pig currently and enabled by default (with what I >> assume is from a newer libc). > > Yes, recent glibc uses it. > > Could you give it a test ride to see whether this makes a difference in > your environment? Yep, I'll give a spin. Won't be before Monday as I'm out of town thu/fri this week, just as a heads-up. If I recall correct, I'd see rseq at 2-3% of overall CPU time last I tested. I'll try and do some pre/post numbers for some of the stuff I usually run. -- Jens Axboe