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Mercier" X-Priority: 3 X-Content-Kind-Code: NORMAL In-Reply-To: X-Drm-Type: N,general X-Msg-Generator: Mail X-Msg-Type: PERSONAL X-Reply-Demand: N Message-ID: <20230118073043epcms1p8b5cfde0d773e296770775581b6ce7105@epcms1p8> Date: Wed, 18 Jan 2023 16:30:43 +0900 X-CMS-MailID: 20230118073043epcms1p8b5cfde0d773e296770775581b6ce7105 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" X-Sendblock-Type: SVC_REQ_APPROVE CMS-TYPE: 101P X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrEJsWRmVeSWpSXmKPExsWy7bCmga7KguPJBg1tvBZz1q9hs1j48C6z xepNvhbdm2cyWvS+f8Vk8efERjaLy7vmsFncW/Of1eL1t2XMFqfufma3eLf+C5sDt8fhN++Z PfZ+W8DisXPWXXaPBZtKPTat6mTz2PRpErvHnWt72DxOzPjN4tG3ZRWjx+dNcgFcUdk2GamJ KalFCql5yfkpmXnptkrewfHO8aZmBoa6hpYW5koKeYm5qbZKLj4Bum6ZOUAXKymUJeaUAoUC EouLlfTtbIryS0tSFTLyi0tslVILUnIKzAr0ihNzi0vz0vXyUkusDA0MjEyBChOyM/Z+PsRe sCW84tyCHSwNjAccuxg5OSQETCTe3T/NAmILCexglHjUKtnFyMHBKyAo8XeHMEhYWMBF4vbq PmaIEiWJsz+usEPEdSWauleDtbIJaEu8XzCJFcQWEVCReDj3J1sXIxcHs8BJZokrfw6xQezi lZjR/pQFwpaW2L58KyOIzSkQKLF34S5miLioxM3Vb9lh7PfH5jNC2CISrffOQtUISjz4uRsq LiVxrvs4E4RdLrFjzn6oXRUSv/uXQc3Rl7jSPxOshlfAV2L2lFawQ1kEVCVOvrnPClHjItHT +QGsl1lAXmL72znMoHBgFtCUWL9LH6JEUWLn77mMECV8Eu++9rDCvLVj3hOoE9QkWp59hYrL SPz99wzK9pBoXtPEAgoTIYF+Jon+9VdZJzAqzEIE9Swkm2chbF7AyLyKUSy1oDg3PbXYsMAQ HrnJ+bmbGMGJV8t0B+PEtx/0DjEycTAeYpTgYFYS4fXbdThZiDclsbIqtSg/vqg0J7X4EKMp 0M8TmaVEk/OBqT+vJN7QxNLAxMzIxMLY0thMSZzXJmJdspBAemJJanZqakFqEUwfEwenVAPT AVObM9aTL87f/Hzf9S0bbTlu/N83iT3gxpzeSVsTl9z+2BGYflWjR3DNjuM7voedUT0Td2XV 96zPki+LanJP/q/edlPvzKH4gp2a9nd/t4rYqltmL/FQa1bp8hE/tYp1ahqHv7nF1VOTr17n Wh56hPv0tRjB7+f5PocZmE58nmifaKvbevH76ewHk3fH8M7qSnU7vXZlTIxnXhXjJIYF05UY 1WP2P1+mcNWjnOPLt/6YlW9KTC/efc2mrPIk4rfXqxz3wMjvz/dfPzcx+t+KZUc+ZvlEBU6V Lepf/Vfe6pLrcukZsxvXPn0ftSQxMnCHLvfUzDfX5Z98jdKYa1GSd1tN+fyePSzsB88vCJzu ukaJpTgj0VCLuag4EQA3viykRQQAAA== DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20230117082521epcas1p22a709521a9e6d2346d06ac220786560d References: <20230117082508.8953-1-jaewon31.kim@samsung.com> <20230117083103epcms1p63382eee1cce1077248a4b634681b0aca@epcms1p6> X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: E937220013 X-Rspam-User: X-Stat-Signature: 3yrdi676w4etdd1beognxwgkn5w5ixqk X-HE-Tag: 1674027048-478923 X-HE-Meta: U2FsdGVkX18yHXN3TjOrk/WVXRkgPjkYem4ZW93SgA/x2xlskTAip8XKQRZDwLHs9SQEppX0DYHvcoVc+wbV9BQGtgBiK4ZpuoaeIf6Jdny+/evrljhWSS780IvRlX5EKGqeE4W8IDBWzQXBLIYgII+cTWhfvQn3g6kJOl27q48Jp6QHUyTjM7fDd1yaHu4TnDP7EpZXKabH29ph9FIHEXMGSed6jDONI5bf/TZ652I99G++vdR5KuvjJbO5lHfyJxZeDOiwQ4mV9C0Gq2AQiiH6ZLJNflbmZ9vtZBeO/vPjjnLk9N4f8o2Y4WlEf8bG65JUSRYabb7JbUknTclG0CjS/qLA7l/jNZXlsKJAaBNY45lhaUkikzmHh2okfFrOdWyBQytb01YNciLnUTR1yTuKhAs1+GhbMrr9v5LHvZu5KdfB/X9sKzIraKqvmTUlqiaa8fovOqsJtU+8zd0fFS+3C7G2u0TKnqbYeMe0utY0JzHSn8sYQ+ZLEe9ZMQ0TDseljvKsJGZh4XhZ3XDEuXrn1WvbpEv+8JR9egbbAZt0kR118+m97lkfJXQEEaZJCOWStTemlrXhnM6pk+OZFwsNuuToezhzzvzqmJYFZKKbslnmKztjJq0WEfBYSIhjDhQSb+9Ee8XEA4iQntxwd21815Zo/wZVztGuCtEF4VtAj0cAOI0+U4X2dZk4lu5pBhbtdW+nv2U9Lh1hiR1AtcwAEfjHIi8jpGvO0Y1ybRaNX3B/AulbNj1jH1/kCpN0ckeuRWwveeMYSTczIi2em8ZYjo1uOhYTa6NeozSIODixNr1c9yVigtAYvBNn6zRR2hJtDuWZZDmOhihkGytOjuuUUrreCveGayMtnZFiqzJPIHil5ApGkM5iFThLO9J7fHaA8IXLxPWAdu907AS9edez6rP82dRgSabFNV0+Iglzj2NbtyrYErCiwsJxrL5I219GJ91RMQOj1p+Tsd/ pK2mWIRK 6mVk+Zba9WU/ikAiRzXrevNGgVQF3D4vGryDSng01fG6UwATxfbGmZ0cPL84e1ParE8R1ir0QVANJN89HI3IVfgWbuqYdXNtVeyY1cpQAJtuef6dWi1bkoq5G7ICTR7X+/OIXeuNcaDMT1NtTtEPPQJOkv/wCYBmZqL+N0qRmvQLXGeyVOrNZI0+kcFhjOPO1d5jyUOBzslSKEu7Z4On7efZp+96i/eqlxQmawiIhwKIOT2uPpf0nsUUEae2A/jk9LlzQDSdHC8pnyCbFRJppcPzCW+bZx9c61GDuNwxD1JhkQ+s= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: >On Tue, Jan 17, 2023 at 12:31 AM Jaewon Kim wrote: >> > Using order 4 pages would be helpful for many IOMMUs, but it could spend >> > quite much time in page allocation perspective. >> > >> > The order 4 allocation with __GFP_RECLAIM may spend much time in >> > reclaim and compation logic. __GFP_NORETRY also may affect. These cause >> > unpredictable delay. >> > >> > To get reasonable allocation speed from dma-buf system heap, use >> > HIGH_ORDER_GFP for order 4 to avoid reclaim. > >Thanks for sharing this! >The case where the allocation gets stuck behind reclaim under pressure >does sound undesirable, but I'd be a bit hesitant to tweak numbers >that have been used for a long while (going back to ion) without a bit >more data. > >It might be good to also better understand the tradeoff of potential >on-going impact to performance from using low order pages when the >buffer is used. Do you have any details like or tests that you could >share to help ensure this won't impact other users? > >TJ: Do you have any additional thoughts on this? > >thanks >-john Let me share what I tested with trace events of compaction, direct_reclaim. This log was captured within one dma-buf alloc for 1,957,888 byte size. It shows direct reclaim spent 4.973 msec total so that it could reclaim 209 pages total. But it spent 12.606 msec in compaction. I might miss preempted time but I think compaction is quite time consuming job. Sorry I don't know how much the current gfp is helpful to IOMMU. I think the default should be set like my change to improve allocation, and the current gfp could be set if need through other options like cmdline. -5972 [006] .... 7971.248176: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x40000 free_pfn=0xffc00 zone_end=0x100000, mode=async -5972 [006] .... 7971.248394: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xac800 free_pfn=0xffc00 zone_end=0x100000, mode=async status=contended -5972 [006] .... 7971.248399: mm_vmscan_direct_reclaim_begin: order=4 gfp_flags=GFP_HIGHUSER|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO -5972 [006] .... 7971.248922: mm_vmscan_direct_reclaim_end: nr_reclaimed=17 -5972 [006] .... 7971.248974: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0xacc00 free_pfn=0xffc00 zone_end=0x100000, mode=async -5972 [006] .... 7971.249063: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xb5c00 free_pfn=0xffc00 zone_end=0x100000, mode=async status=contended -5972 [006] .... 7971.249067: mm_vmscan_direct_reclaim_begin: order=4 gfp_flags=GFP_HIGHUSER|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO -5972 [006] .... 7971.249768: mm_vmscan_direct_reclaim_end: nr_reclaimed=18 -5972 [006] .... 7971.249843: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0xb6000 free_pfn=0xafc00 zone_end=0x100000, mode=async -5972 [006] .... 7971.249845: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xb6000 free_pfn=0xafc00 zone_end=0x100000, mode=async status=partial_skipped -5972 [006] .... 7971.249849: mm_vmscan_direct_reclaim_begin: order=4 gfp_flags=GFP_HIGHUSER|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO -5972 [006] .... 7971.250116: mm_vmscan_direct_reclaim_end: nr_reclaimed=22 -5972 [006] .... 7971.250152: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x40000 free_pfn=0xaf800 zone_end=0x100000, mode=async -5972 [006] .... 7971.250305: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xac400 free_pfn=0xaf800 zone_end=0x100000, mode=async status=success -5972 [006] .... 7971.250375: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0xac800 free_pfn=0xaf800 zone_end=0x100000, mode=async -5972 [006] .... 7971.250380: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xaf800 free_pfn=0xaf800 zone_end=0x100000, mode=async status=partial_skipped -5972 [006] .... 7971.250384: mm_vmscan_direct_reclaim_begin: order=4 gfp_flags=GFP_HIGHUSER|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO -5972 [006] .... 7971.250597: mm_vmscan_direct_reclaim_end: nr_reclaimed=20 -5972 [006] .... 7971.251289: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x40000 free_pfn=0xaf000 zone_end=0x100000, mode=async -5972 [006] .... 7971.251497: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xac400 free_pfn=0xaf000 zone_end=0x100000, mode=async status=contended -5972 [006] .... 7971.251502: mm_vmscan_direct_reclaim_begin: order=4 gfp_flags=GFP_HIGHUSER|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO -5972 [006] .... 7971.251797: mm_vmscan_direct_reclaim_end: nr_reclaimed=22 -5972 [006] .... 7971.251890: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x5b400 free_pfn=0xb0400 zone_end=0x100000, mode=sync -5972 [006] .... 7971.252740: mm_compaction_end: zone_start=0x40000 migrate_pfn=0x63800 free_pfn=0xb0400 zone_end=0x100000, mode=sync status=success -5972 [006] .... 7971.252774: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x63c00 free_pfn=0xb0000 zone_end=0x100000, mode=async -5972 [006] .... 7971.253325: mm_compaction_end: zone_start=0x40000 migrate_pfn=0x74e20 free_pfn=0xade92 zone_end=0x100000, mode=async status=success -5972 [006] .... 7971.253333: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x83400 free_pfn=0xafc00 zone_end=0x100000, mode=async -5972 [006] .... 7971.253683: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xac400 free_pfn=0xafc00 zone_end=0x100000, mode=async status=contended -5972 [006] .... 7971.253688: mm_vmscan_direct_reclaim_begin: order=4 gfp_flags=GFP_HIGHUSER|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO -5972 [006] .... 7971.254134: mm_vmscan_direct_reclaim_end: nr_reclaimed=22 -5972 [006] .... 7971.254206: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0xad000 free_pfn=0xafc00 zone_end=0x100000, mode=async -5972 [006] .... 7971.254289: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xae1c0 free_pfn=0xae000 zone_end=0x100000, mode=async status=partial_skipped -5972 [006] .... 7971.254304: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x40000 free_pfn=0xffc00 zone_end=0x100000, mode=async -5972 [006] .... 7971.254510: mm_compaction_end: zone_start=0x40000 migrate_pfn=0x74db0 free_pfn=0xadcc1 zone_end=0x100000, mode=async status=success -5972 [006] .... 7971.254519: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x75000 free_pfn=0xffc00 zone_end=0x100000, mode=async -5972 [006] .... 7971.254612: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xac400 free_pfn=0xffc00 zone_end=0x100000, mode=async status=contended -5972 [006] .... 7971.254617: mm_vmscan_direct_reclaim_begin: order=4 gfp_flags=GFP_HIGHUSER|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO -5972 [006] .... 7971.255303: mm_vmscan_direct_reclaim_end: nr_reclaimed=22 -5972 [006] .... 7971.255307: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x75000 free_pfn=0xffc00 zone_end=0x100000, mode=sync -5972 [006] .... 7971.260198: mm_compaction_end: zone_start=0x40000 migrate_pfn=0x751e5 free_pfn=0xaa83f zone_end=0x100000, mode=sync status=success -5972 [006] .... 7971.260236: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x40000 free_pfn=0xffc00 zone_end=0x100000, mode=async -5972 [006] .... 7971.260883: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xb5c00 free_pfn=0xffc00 zone_end=0x100000, mode=async status=contended -5972 [006] .... 7971.260891: mm_vmscan_direct_reclaim_begin: order=4 gfp_flags=GFP_HIGHUSER|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO -5972 [006] .... 7971.261174: mm_vmscan_direct_reclaim_end: nr_reclaimed=22 -5972 [006] .... 7971.261178: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x75000 free_pfn=0xffc00 zone_end=0x100000, mode=sync -5972 [006] .... 7971.264861: mm_compaction_end: zone_start=0x40000 migrate_pfn=0x75681 free_pfn=0xffc00 zone_end=0x100000, mode=sync status=success -5972 [006] .... 7971.264873: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0xbbc00 free_pfn=0xffc00 zone_end=0x100000, mode=async -5972 [006] .... 7971.264889: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xc1400 free_pfn=0xffc00 zone_end=0x100000, mode=async status=contended -5972 [006] .... 7971.264891: mm_vmscan_direct_reclaim_begin: order=4 gfp_flags=GFP_HIGHUSER|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO -5972 [006] .... 7971.265141: mm_vmscan_direct_reclaim_end: nr_reclaimed=22 -5972 [002] .... 7971.265585: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0xc1800 free_pfn=0xffc00 zone_end=0x100000, mode=async -5972 [002] .... 7971.265669: mm_compaction_end: zone_start=0x40000 migrate_pfn=0xc2c00 free_pfn=0xffc00 zone_end=0x100000, mode=async status=contended -5972 [002] .... 7971.265678: mm_vmscan_direct_reclaim_begin: order=4 gfp_flags=GFP_HIGHUSER|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO -5972 [002] .... 7971.266987: mm_vmscan_direct_reclaim_end: nr_reclaimed=22 -5972 [006] .... 7971.267466: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x40000 free_pfn=0xffc00 zone_end=0x100000, mode=sync -5972 [006] .... 7971.267778: mm_compaction_end: zone_start=0x40000 migrate_pfn=0x5d000 free_pfn=0xffc00 zone_end=0x100000, mode=sync status=success -5972 [006] .... 7971.267927: mm_compaction_begin: zone_start=0x40000 migrate_pfn=0x5c000 free_pfn=0xffc00 zone_end=0x100000, mode=async -5972 [006] .... 7971.268092: mm_compaction_end: zone_start=0x40000 migrate_pfn=0x74d70 free_pfn=0xffc00 zone_end=0x100000, mode=async status=success Thank you Jaewon Kim