Return-Path: Message-ID: <1460307544.1800.53.camel@perches.com> Subject: Re: [PATCH] Bluetooth: Deinline large functions From: Joe Perches To: Denys Vlasenko , Johan Hedberg Cc: linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org Date: Sun, 10 Apr 2016 09:59:04 -0700 In-Reply-To: <1460305444-14159-1-git-send-email-dvlasenk@redhat.com> References: <1460305444-14159-1-git-send-email-dvlasenk@redhat.com> Content-Type: text/plain; charset="ISO-8859-1" Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: On Sun, 2016-04-10 at 18:24 +0200, Denys Vlasenko wrote: > Fastest existing Bluetooth standard's top speed is 2.4 MB/s. > It is way off from being CPU limited, no need to squeeze > last few cycles by excessive inlining. > > This patch delinlines the following functions: > > hci_conn_hash_lookup_handle: 345 bytes, 39 calls > hci_conn_hash_lookup_ba: 372 bytes, 36 calls > hci_conn_hash_lookup_le: 382 bytes, 8 calls > hci_conn_hash_lookup_state: 356 bytes, 3 calls > hci_lookup_le_connect: 378 bytes, 7 calls > hci_conn_drop: 186 bytes, 30 calls > hci_connect_cfm: 121 bytes, 15 calls > hci_disconn_cfm: 121 bytes, 2 calls > hci_auth_cfm: 156 bytes, 2 calls > hci_encrypt_cfm: 156 bytes, 3 calls > > Size reduction is about 40k: > > ????text?????data??????bss???????dec?????hex filename > 95943139 20860256 35991552 152794947 91b7743 vmlinux_before > 95903714 20860256 35991552 152755522 91add42 vmlinux Hello Denys While removing unnecessary inlines is generally a good thing, for extremely low power embedded systems like a coin-battery operated bicycle computer or a heart rate monitor, this might cause a throughput reduction. Also, the size decrease for a defconfig should be quite a bit smaller than this. Can you please also show the size decrease when done with a defconfig with bluetooth support? And for these types of patches in general, please add a defconfig size reduction to the commit message. This is an x86-64 defconfig with bluetooth with and without this patch: $ size vmlinux.defconfig.* ???text ???data ????bss ????dec ????hex filename 10214414 4313816 1097728 15625958 ?ee6ee6 vmlinux.defconfig.new 10224014 4313816 1097728 15635558 ?ee9466 vmlinux.defconfig.old ~10k total