Re: [PATCH v4 28/39] unwind_user/deferred: Add deferred unwinding interface
From: Peter Zijlstra <peterz@infradead.org>
Date: 2025-01-22 13:37:47
Also in:
linux-perf-users, linux-toolchains, lkml
On Tue, Jan 21, 2025 at 06:31:20PM -0800, Josh Poimboeuf wrote:
+/* + * The context cookie is a unique identifier which allows post-processing to + * correlate kernel trace(s) with user unwinds. The high 12 bits are the CPU
s/12/16/ ?
+ * id; the lower 48 bits are a per-CPU entry counter.
+ */
+static u64 ctx_to_cookie(u64 cpu, u64 ctx)
+{
+ BUILD_BUG_ON(NR_CPUS > 65535);
+ return (ctx & ((1UL << 48) - 1)) | (cpu << 48);
+}