From mboxrd@z Thu Jan 1 00:00:00 1970 From: venkappa.m@samsung.com (Venkappa Mala) Date: Thu, 19 Feb 2015 12:26:01 +0000 (UTC) Subject: [PATCH v10 4/6] ARM: add vdso user-space code References: <1411413485-7675-1-git-send-email-nathan_lynch@mentor.com> <1411413485-7675-5-git-send-email-nathan_lynch@mentor.com> <54E24D7B.3050806@mentor.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Nathan Lynch mentor.com> writes: > Hi, > > Sorry for not seeing this earlier but it doesn't look like my address > was in the recipients list, and I just happened to catch up on list > traffic today. > > It looks like Catalin already covered everything, but just to sum up - - > the patches need to be updated to avoid enabling the VDSO gettimeofday > on systems where CNTVCT is not usable, for whatever reason. I do not > intend to enable user space / VDSO access to CNTPCT to accommodate > systems that don't initialize the virtual counter/offset correctly. > Hello Nathan, Now, it's clear about current vDSO patch set and it is validated with virtual timer/VCT by using workaround with the below results on ARMv7-A: CortexA7: Quad core, 1.2GHz, About 1 iteration (gettimeofday), WITHOUT VDSO : 30-35 ?sec WITH VDSO : 4-7 ?sec About 1000 iteration (gettimeofday), WITHOUT VDSO : 27-30 msec WITH VDSO : 13-15 msec As you have mentioned about avoid enabling the VDSO gettimeofday on systems where CNTVCT is not usable, for whatever reason, please take care about this one in the updated patch list so that the things will be very clean. Meanwhile, i will discuss further on "firmware is broken about CNTVOFF initialization zero + HYP disabled" in the following thread as mentioned in the previous reply to Catalin, arm: Handle starting up in secure mode https://lkml.org/lkml/2014/9/16/552 Thanks for the patch list, BR, Venkappa