From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 09 Oct 2020 10:24:09 +0900 Message-ID: From: Hajime Tazaki Subject: Re: [RFC v7 07/21] um: extend arch_switch_to for alternate SUBARCH In-Reply-To: <5502f24bcdc07372fbc5ee86c700770038b041c4.camel@sipsolutions.net> References: <5502f24bcdc07372fbc5ee86c700770038b041c4.camel@sipsolutions.net> MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII To: johannes@sipsolutions.net Cc: linux-um@lists.infradead.org, jdike@addtoit.com, richard@nod.at, anton.ivanov@cambridgegreys.com, tavi.purdila@gmail.com, linux-kernel-library@freelists.org, linux-arch@vger.kernel.org, retrage01@gmail.com List-ID: On Thu, 08 Oct 2020 00:25:06 +0900, Johannes Berg wrote: > > On Tue, 2020-10-06 at 18:44 +0900, Hajime Tazaki wrote: > > This commit introduces additional argument of previous task when > > context switch happens. New SUBARCH can use the new information to > > switch tasks in a subarch-specific manner. > > > > The patch is particularly required by nommu mode implemented as a > > SUBARCH of UML. > > Would probably be good to already say why here? Agree. The patch is particularly required by nommu mode because it uses previous task information to control the previous thread (e.g., down semaphore, terminate thread, clean up thread flags). Something like this ? -- Hajime