From: vbabka@suse.cz (Vlastimil Babka) Date: Wed, 16 Mar 2016 13:03:21 +0100 Subject: Suspicious error for CMA stress test In-Reply-To: References: <56D93ABE.9070406@huawei.com> <20160307043442.GB24602@js1304-P5Q-DELUXE> <56DD38E7.3050107@huawei.com> <56DDCB86.4030709@redhat.com> <56DE30CB.7020207@huawei.com> <56DF7B28.9060108@huawei.com> <56E2FB5C.1040602@suse.cz> <20160314064925.GA27587@js1304-P5Q-DELUXE> <56E662E8.700@suse.cz> <20160314071803.GA28094@js1304-P5Q-DELUXE> <56E6AED1.6060703@suse.cz> Message-ID: <56E94B89.80706@suse.cz> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/14/2016 03:10 PM, Joonsoo Kim wrote: > 2016-03-14 21:30 GMT+09:00 Vlastimil Babka : > > Now I see why this happen. I enabled CONFIG_DEBUG_PAGEALLOC > and it makes difference. > > I tested on x86_64, gcc (Ubuntu 4.8.4-2ubuntu1~14.04.1) 4.8.4. > > With CONFIG_CMA + CONFIG_DEBUG_PAGEALLOC > ./scripts/bloat-o-meter page_alloc_base.o page_alloc_vlastimil_orig.o > add/remove: 0/0 grow/shrink: 2/0 up/down: 510/0 (510) > function old new delta > free_one_page 1050 1334 +284 > free_pcppages_bulk 1396 1622 +226 > > ./scripts/bloat-o-meter page_alloc_base.o page_alloc_mine.o > add/remove: 0/0 grow/shrink: 2/0 up/down: 351/0 (351) > function old new delta > free_one_page 1050 1230 +180 > free_pcppages_bulk 1396 1567 +171 > > > With CONFIG_CMA + !CONFIG_DEBUG_PAGEALLOC > (pa_b is base, pa_v is yours and pa_m is mine) > > ./scripts/bloat-o-meter pa_b.o pa_v.o > add/remove: 0/0 grow/shrink: 1/1 up/down: 88/-23 (65) > function old new delta > free_one_page 761 849 +88 > free_pcppages_bulk 1117 1094 -23 > > ./scripts/bloat-o-meter pa_b.o pa_m.o > add/remove: 0/0 grow/shrink: 2/0 up/down: 329/0 (329) > function old new delta > free_one_page 761 1031 +270 > free_pcppages_bulk 1117 1176 +59 > > Still, it has difference but less than before. > Maybe, we are still using different configuration. Could you > check if CONFIG_DEBUG_VM is enabled or not? In my case, it's not It's disabled here. > enabled. And, do you think this bloat isn't acceptable? Well, it is quite significant. But given that Hanjun sees the errors still, it's not the biggest issue now :/ > Thanks. >