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[35.233.145.57]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1ff58f29e18sm89049615ad.11.2024.08.06.07.47.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Aug 2024 07:47:56 -0700 (PDT) Date: Tue, 6 Aug 2024 14:47:52 +0000 From: Carlos Llamas To: Waiman Long Cc: Andrew Morton , linux-kernel@vger.kernel.org, kernel-team@android.com, Peter Zijlstra , Boqun Feng , Ingo Molnar , Will Deacon Subject: Re: [PATCH 2/3] lockdep: clarify size for LOCKDEP_*_BITS configs Message-ID: References: <20240806010128.402852-1-cmllamas@google.com> <20240806010128.402852-3-cmllamas@google.com> <218314e9-7c7c-490c-bb2e-9611243cade3@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <218314e9-7c7c-490c-bb2e-9611243cade3@redhat.com> On Mon, Aug 05, 2024 at 09:36:43PM -0400, Waiman Long wrote: > > Many kernel developers understand that BITS refers to a size of 2^n. Besides > LOCKDEP, there are also many instances of such use in other kconfig entries. > It can be a bit odd to explicitly state that just for LOCKDEP. > > Cheers, > Longman Right, and similar to BITS there is SHIFT, which is also a common way to specify the 2^n values. I'd point out though, that it is also common to clarify the "power of two" explicitly. To name a few examples that are doing so: SECURITY_SELINUX_SIDTAB_HASH_BITS, NODES_SHIFT, CMA_ALIGNMENT, IP_VS_SH_TAB_BITS, LOG_BUF_SHIFT but there is more. Perhaps this is because the audience for these configs is not always a kernel developer? Anyway, this is pretty much a trivial patch to address Andrew's comment below. But let me know if you think I should drop it, it seems to me it can be helpful. [...] btw, the help text "Bitsize for MAX_LOCKDEP_CHAINS" is odd. What's a bitsize? Maybe "bit shift count for..." or such. Thanks, -- Carlos Llamas