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Marchesi" , Beau Belgrave , Linus Torvalds , Andrew Morton , Florian Weimer , Kees Cook , Carlos O'Donell , Sam James , Dylan Hatch , Borislav Petkov , Dave Hansen , David Hildenbrand , "H. Peter Anvin" , "Liam R. Howlett" , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Suren Baghdasaryan , Vlastimil Babka , Heiko Carstens , Vasily Gorbik Subject: Re: [PATCH v13 00/18] unwind_deferred: Implement sframe handling Message-ID: <20260205135411.5fb22df2@gandalf.local.home> In-Reply-To: References: <20260127150554.2760964-1-jremus@linux.ibm.com> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam11 X-Stat-Signature: 34m6appoctf5a1m933b61or15i9hqscy X-Rspam-User: X-Rspamd-Queue-Id: 020CD40005 X-HE-Tag: 1770317620-132922 X-HE-Meta: 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 EzwNkqYt jeoZfy/uj54kDR3wz0PfAUkHUSGR3JoNFAWETtpqy/7AQ/szhvnZlzeM02TTAUtlVYTDk/ra64AyZuzC0ENvFp3paqD7r6hp4OzIM3Hp6iKpOU5n346DyqJWObJFYpo0DUicghrnJdrH21IAb7kJX/m3Z79Qylm+SW+CN+fr3QbDC1htjGW4RS1IIc9EL2n0FeSylPyJZvf5uqIG4yW/f7JV/RV+dj/5q7cLJfuis5zuxQoKXI6Wd7hrv/bJ/A2rsItJA X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, 5 Feb 2026 10:26:10 -0800 Namhyung Kim wrote: > > Namhyung Kim's related perf tools deferred callchain support can be used > > for testing ("perf record --call-graph fp,defer" and "perf report/script"). > > Is it possible for users to choose the unwinder - frame pointer or > SFrame at runtime? I feel like the option should be > "--call-graph sframe,defer" or just "--call-graph sframe" if it always > uses deferred unwinding. Currently no, and I'm not sure we want that do we? The idea is to use the best option that is available. Why use frame pointers if sframe is available and it's being called with defer? If there's no defer, then sframes are not available, so it defaults to the best option available (which will likely be frame pointers). -- Steve