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Thu, 12 Nov 2026 10:33:27 -0800 (PST) Received: from krava ([173.38.220.46]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-c5095a5a78csm7085066b.4.2026.11.12.10.33.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Nov 2026 10:33:27 -0800 (PST) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Thu, 12 Nov 2026 19:33:24 +0100 To: Peter Zijlstra Cc: Masami Hiramatsu , Naveen N Rao , "David S. Miller" , Josh Poimboeuf , Jason Baron , Alice Ryhl , Steven Rostedt , Ard Biesheuvel , Thomas Gleixner , Ingo Molnar , Alan Maguire , x86@kernel.org, linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH 01/13] static_call: Index code text reservation lookups Message-ID: References: <20261109194916.1089703-1-jolsa@kernel.org> <20261109194916.1089703-2-jolsa@kernel.org> <20261112082709.GC2668804@noisy.programming.kicks-ass.net> X-Mailing-List: bpf@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261112082709.GC2668804@noisy.programming.kicks-ass.net> On Thu, Nov 12, 2026 at 09:27:09AM +0100, Peter Zijlstra wrote: > On Mon, Nov 09, 2026 at 08:49:04PM +0100, Jiri Olsa wrote: > > Text reservation checks scan every static call site. Build an address-sorted > > index for core text sites and use binary search to find the starting point > > near the requested range. > > > > Module indexing is intentionally unsupported. Module reservation checks > > continue to use a linear scan, avoiding per-module index allocation and > > teardown complexity. > > So this changelog leaves me wondering why, and at what cost. Why do I > want to have this extra array in my kernel and such. right, I'll include benchmark numbers for each change jirka