From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx180.postini.com [74.125.245.180]) by kanga.kvack.org (Postfix) with SMTP id 8F1D76B0135 for ; Tue, 30 Apr 2013 13:53:02 -0400 (EDT) Date: Tue, 30 Apr 2013 17:53:00 +0000 From: Christoph Lameter Subject: Re: [PATCH 1/2] Make the batch size of the percpu_counter configurable In-Reply-To: <1367344094.27102.182.camel@schen9-DESK> Message-ID: <0000013e5c1377c5-49a8fca5-eb04-4e3a-a507-ce3a47fea685-000000@email.amazonses.com> References: <0000013e5b24d2c5-9b899862-e2fd-4413-8094-4f1e5a0c0f62-000000@email.amazonses.com> <1367339009.27102.174.camel@schen9-DESK> <0000013e5bfd1548-a6ef7962-7b00-495b-8e83-d7a08413e165-000000@email.amazonses.com> <1367344094.27102.182.camel@schen9-DESK> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Tim Chen Cc: Andrew Morton , Tejun Heo , Al Viro , Dave Hansen , Andi Kleen , linux-kernel , linux-mm On Tue, 30 Apr 2013, Tim Chen wrote: > > And why is it a pointer? > > A pointer because the default percpu_counter_batch value could change > later when cpus come online after we initialize per cpu counter and > percpu_counter_batch will get computed again in percpu_counter_startup. > Making it a pointer will make it unnecessary to come back and change the > batch sizes if we use static batch value and default batch size. But you will have to dereference the pointer whenever you want the batch size from the hot path. Looks like it would be better to put the value there directly. You have a list of percpu counters that can be traversed to change the batch size. -- 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