From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Mon, 24 Aug 2015 15:36:20 +0100 Subject: [PATCH 0/4] Efficiency cleanups In-Reply-To: <20150821134630.GW7557@n2100.arm.linux.org.uk> References: <20150821133043.GV7557@n2100.arm.linux.org.uk> <20150821134630.GW7557@n2100.arm.linux.org.uk> Message-ID: <20150824143619.GD20147@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Aug 21, 2015 at 02:46:30PM +0100, Russell King - ARM Linux wrote: > While developing the previous patch set, I noticed that the kernel's > "fast" exit path efficiency was not what it's supposed to be due to the > addition of trace and context tracking. > > These add several instances of register stacking and unstacking around > various function calls, several of which we can avoid. Many of these > instances don't need to stack any register other than r0. > > Moreover, we can avoid stacking and unstacking r0 if these features are > enabled by storing r0 in the pt_regs as we would do in our slow return > path. > > Various other cleanups are included in this set as well. Acks welcome. All four patches look fine to me: Acked-by: Will Deacon For some reason, I thought the numbering of the TIF_ flags was important for some immediate construction in asm code, but either I'm mistaken or it's no longer the case. Will