From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f198.google.com (mail-qk0-f198.google.com [209.85.220.198]) by kanga.kvack.org (Postfix) with ESMTP id A9D266B025F for ; Tue, 25 Jul 2017 14:33:54 -0400 (EDT) Received: by mail-qk0-f198.google.com with SMTP id s18so75831646qks.4 for ; Tue, 25 Jul 2017 11:33:54 -0700 (PDT) Received: from mail-qt0-x244.google.com (mail-qt0-x244.google.com. [2607:f8b0:400d:c0d::244]) by mx.google.com with ESMTPS id s13si11641770qki.511.2017.07.25.11.33.53 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 25 Jul 2017 11:33:53 -0700 (PDT) Received: by mail-qt0-x244.google.com with SMTP id i19so5046451qte.1 for ; Tue, 25 Jul 2017 11:33:53 -0700 (PDT) Date: Tue, 25 Jul 2017 14:33:52 -0400 From: Josef Bacik Subject: Re: [PATCH v2 12/23] percpu: increase minimum percpu allocation size and align first regions Message-ID: <20170725183351.GL18880@destiny> References: <20170724230220.21774-1-dennisz@fb.com> <20170724230220.21774-13-dennisz@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170724230220.21774-13-dennisz@fb.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dennis Zhou Cc: Tejun Heo , Christoph Lameter , Josef Bacik , linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com, Dennis Zhou On Mon, Jul 24, 2017 at 07:02:09PM -0400, Dennis Zhou wrote: > From: "Dennis Zhou (Facebook)" > > This patch increases the minimum allocation size of percpu memory to > 4-bytes. This change will help minimize the metadata overhead > associated with the bitmap allocator. The assumption is that most > allocations will be of objects or structs greater than 2 bytes with > integers or longs being used rather than shorts. > > The first chunk regions are now aligned with the minimum allocation > size. The reserved region is expected to be set as a multiple of the > minimum allocation size. The static region is aligned up and the delta > is removed from the dynamic size. This works because the dynamic size is > increased to be page aligned. If the static size is not minimum > allocation size aligned, then there must be a gap that is added to the > dynamic size. The dynamic size will never be smaller than the set value. > > Signed-off-by: Dennis Zhou Reviewed-by: Josef Bacik Thanks, Josef -- 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