From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1886A17C21E; Fri, 13 Dec 2024 17:10:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734109815; cv=none; b=Ek6fvjLs/MjxlnzoFS3CmvxyGR3aMM+UMPgLLNUOdFZDsTucwWf7QuJpDa5NayThIatZ4TJt291UuDWO2xi39E1XfVxCl638AuFSrLzJsfAZH906wtaHiSiajiA8l+h7B/T+HabJWrWIy4LXFSrrYci/9xw/Qfr1ymsl6M+DPAg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734109815; c=relaxed/simple; bh=FzbxNtPRI9eJSeo8RCJjgFaAAq9gXHyaLbj1CzzKD8w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QxJ8E7Wwa6N/vF/xLgxJ3hk8yl0kZIgil2hBADnMZ4JvDdgYRqDnw027dcl536q/MfanfTCV5oTo5aQjRU5KHuCdePAf601xt6iY6KLVlhGFILPMiYV3wCpq6IbrvFDxnDH++qQZUEA0XBWxXK2nWbbEg8IIzucAmdTFnZMjTpw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LLSB5NV7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LLSB5NV7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CF73C4CED0; Fri, 13 Dec 2024 17:10:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1734109814; bh=FzbxNtPRI9eJSeo8RCJjgFaAAq9gXHyaLbj1CzzKD8w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LLSB5NV7qLwPeUWsPfcfbfreuZjY4hYPf9J+yxiOD+gJdl6N7KFAQArDJ8a4dFWx0 FwCuqwbwOpMF0fhib95adoQ6urHuUg2tUMs20eJXhMVDMZg18u6b3iS7SnZcqka7K5 BwgLPiWP2h+lWwacvklTgbZ8D6MNWyCYCNCqFuD9NYtwa2ovDMolOxZMMBd6Sr/WDX X9b143zzvPsrGosV45ozXfsLoxBfrBmMAkjEMXUrCnUzrpd6Ywu/y233fl827WQU3e JT+C5rF2uaP9h6RYmYBBPxX3WRRkOlGJM++6VJ13iEqM6i5gixFszEEMvzkrlXjSu8 8jJTkdoTF45mw== Date: Fri, 13 Dec 2024 09:10:12 -0800 From: Namhyung Kim To: Ian Rogers Cc: Arnaldo Carvalho de Melo , Kan Liang , Jiri Olsa , Adrian Hunter , Peter Zijlstra , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org, Andrii Nakryiko , Song Liu , bpf@vger.kernel.org, Stephane Eranian , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Kees Cook Subject: Re: [PATCH v2 0/4] perf lock contention: Symbolize locks using slab cache names Message-ID: References: <20241108061500.2698340-1-namhyung@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Hello, On Mon, Nov 18, 2024 at 10:35:43AM -0800, Namhyung Kim wrote: > On Mon, Nov 11, 2024 at 11:46:37AM -0800, Ian Rogers wrote: > > On Thu, Nov 7, 2024 at 10:15 PM Namhyung Kim wrote: > > > > > > Hello, > > > > > > This is to support symbolization of dynamic locks using slab > > > allocator's metadata. The kernel support is in the bpf-next tree now. > > > > > > It provides the new "kmem_cache" BPF iterator and "bpf_get_kmem_cache" > > > kfunc to get the information from an address. The feature detection is > > > done using BTF type info and it won't have any effect on old kernels. > > > > > > v2 changes) > > > > > > * don't use libbpf_get_error() (Andrii) > > > > > > v1) https://lore.kernel.org/linux-perf-users/20241105172635.2463800-1-namhyung@kernel.org > > > > > > With this change, it can show locks in a slab object like below. I > > > added "&" sign to distinguish them from global locks. > > > > I know the & is intentional but I worry it could later complicate > > parsing of filters. Perhaps @ is a viable alternative. Other than > > that: > > > > Acked-by: Ian Rogers > > Thanks for the review! > > I don't think it clashes with BPF sample filters which works on sample > data generated from a perf_event. Technically this command doesn't use > perf_event and just attaches the BPF program to tracepoint directly. > > Also sample filters don't use '&' symbol in the syntax as of now. :) Can we merge this series if no more feedback? About the build issue, I think it's transient and it's not the default to build with generated vmlinux.h. We could disable the generation but it might be better to keep it to test other issues. Anyway, it can be done independently. Thanks, Namhyung