From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f179.google.com (mail-ob0-f179.google.com [209.85.214.179]) by kanga.kvack.org (Postfix) with ESMTP id AA6BD6B0038 for ; Tue, 18 Nov 2014 23:19:30 -0500 (EST) Received: by mail-ob0-f179.google.com with SMTP id va2so3562368obc.24 for ; Tue, 18 Nov 2014 20:19:30 -0800 (PST) Received: from aserp1040.oracle.com (aserp1040.oracle.com. [141.146.126.69]) by mx.google.com with ESMTPS id bq7si377971obb.79.2014.11.18.20.19.28 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 18 Nov 2014 20:19:29 -0800 (PST) Message-ID: <546C18C5.5090508@oracle.com> Date: Tue, 18 Nov 2014 23:12:53 -0500 From: Sasha Levin MIME-Version: 1.0 Subject: Re: mm: shmem: freeing mlocked page References: <545C4A36.9050702@oracle.com> <5466142C.60100@oracle.com> <20141118135843.bd711e95d3977c74cf51d803@linux-foundation.org> <546C1202.1020502@oracle.com> <20141118195656.f80ff650.akpm@linux-foundation.org> In-Reply-To: <20141118195656.f80ff650.akpm@linux-foundation.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Hugh Dickins , "linux-mm@kvack.org" , LKML , Dave Jones , Jens Axboe On 11/18/2014 10:56 PM, Andrew Morton wrote: >> Trinity can't really log anything because attempts to log syscalls slow everything >> > down to a crawl to the point nothing reproduces. > Ah. I was thinking that it could be worked out by looking at the > trinity source around where it calls splice(). But I suspect that > doesn't make sense if trinity just creates a zillion threads each of > which sprays semi-random syscalls at the kernel(?). I think Dave would agree here that this is a rather accurate description of Trinity :) >> > I've just looked at that trace above, and got a bit more confused. I didn't think >> > that you can mlock page cache. How would a user do that exactly? > mmap it then mlock it! The kernel will fault everything in for you > then pin it down. But that's a pipe buffer, I didn't think userspace can mmap pipes? I have some reading to do. Thanks, Sasha -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org