Hi Gregory, On Tue, Feb 16, 2016 at 04:33:35PM +0100, Gregory CLEMENT wrote: > Hello, > > A few weeks ago I sent a proposal for a API set for HW Buffer > management, to have a better view of the motivation for this API see > the cover letter of this proposal: > http://thread.gmane.org/gmane.linux.kernel/2125152 > > Since this version I took into account the review from Florian: > - The hardware buffer management helpers are no more built by default > and now depend on a hidden config symbol which has to be selected > by the driver if needed > - The hwbm_pool_refill() and hwbm_pool_add() now receive a gfp_t as > argument allowing the caller to specify the flag it needs. > - buf_num is now tested to ensure there is no wrapping > - A spinlock has been added to protect the hwbm_pool_add() function in > SMP or irq context. > > I also used pr_warn instead of pr_debug in case of errors. > > I fixed the mvneta implementation by returning the buffer to the pool > at various place instead of ignoring it. > > About the series itself I tried to make this series easier to merge: > - Squashed "bus: mvenus-mbus: Fix size test for > mvebu_mbus_get_dram_win_info" into bus: mvebu-mbus: provide api for > obtaining IO and DRAM window information. > - Added my signed-otf-by on all the patches as submitter of the series. > - Renamed the dts patches with the pattern "ARM: dts: platform:" > - Removed the patch "ARM: mvebu: enable SRAM support in > mvebu_v7_defconfig" of this series and already applied it > - Rodified the order of the patches. > > In order to ease the test the branch mvneta-BM-framework-v2 is > available at g...@github.com:MISL-EBU-System-SW/mainline-public.git.
Well, I tested this patch series on top of latest master (from today) on my fresh new clearfog board. I compared carefully with and without the patchset. My workload was haproxy receiving connections and forwarding them to my PC via the same port. I tested both with short connections (HTTP GET of an empty file) and long ones (1 MB or more). No trouble was detected at all, which is pretty good. I noticed a very tiny performance drop which is more noticeable on short connections (high packet rates), my forwarded connection rate went down from 17500/s to 17300/s. But I have not checked yet what can be tuned when using the BM, nor did I compare CPU usage. I remember having run some tests in the past, I guess it was on the XP-GP board, and noticed that the BM could save a significant amount of CPU and improve cache efficiency, so if this is the case here, we don't really care about a possible 1% performance drop. I'll try to provide more results as time permits. In the mean time if you want (or plan to submit a next batch), feel free to add a Tested-by: Willy Tarreau <w...@1wt.eu>. cheers, Willy
