|From:||Andrew Morton <akpm-AT-linux-foundation.org>|
|To:||Ankita Garg <ankita-AT-in.ibm.com>|
|Subject:||Re: [PATCH 00/10] mm: Linux VM Infrastructure to support Memory Power Management|
|Date:||Sat, 28 May 2011 00:56:40 -0700|
|Cc:||linux-arm-kernel-AT-lists.infradead.org, linux-mm-AT-kvack.org, linux-kernel-AT-vger.kernel.org, linux-pm-AT-lists.linux-foundation.org, svaidy-AT-linux.vnet.ibm.com, thomas.abraham-AT-linaro.org|
On Fri, 27 May 2011 18:01:28 +0530 Ankita Garg <email@example.com> wrote: > This patchset proposes a generic memory regions infrastructure that can be > used to tag boundaries of memory blocks which belongs to a specific memory > power management domain and further enable exploitation of platform memory > power management capabilities. A couple of quick thoughts... I'm seeing no estimate of how much energy we might save when this work is completed. But saving energy is the entire point of the entire patchset! So please spend some time thinking about that and update and maintain the [patch 0/n] description so others can get some idea of the benefit we might get from all of this. That estimate should include an estimate of what proportion of machines are likely to have hardware which can use this feature and in what timeframe. IOW, if it saves one microwatt on 0.001% of machines, not interested ;) Also, all this code appears to be enabled on all machines? So machines which don't have the requisite hardware still carry any additional overhead which is added here. I can see that ifdeffing a feature like this would be ghastly but please also have a think about the implications of this and add that discussion also. If possible, it would be good to think up some microbenchmarks which probe the worst-case performance impact and describe those and present the results. So others can gain an understanding of the runtime costs. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to firstname.lastname@example.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"email@example.com"> firstname.lastname@example.org </a>
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