▲ 119 ▼ Why btrfs gets huge perf hit with background IO work? (lemmy.world) submitted 2 years ago by Alawami@lemmy.world to c/linux@lemmy.ml 37 comments fedilink hide all child comments
[–] redcalcium@lemmy.institute 22 points 2 years ago (1 child) I think it's not btrfs that's slow, it's bcachefs that's insanely fast. Bcachefs almost as fast as ext4 while having that many features is insane. permalink fedilink source hideshow 2 child comments replies: [–] Chewy7324@discuss.tchncs.de 22 points 2 years ago* (last edited 2 years ago) (1 child) This screenshot is the only metric where btrfs is incredibly slow. Bcachefs random and sequential writes and reads are much slower than other filesystems in this benchmark. I have no idea how the actual real world performance will be. Bcachefs still misses a lot of features so I'll continue to follow the development, hopefully including performance improvements. Bcachefs sequential write performance in this out-of-the-box comparison was coming in at around half the speed of Btrfs while XFS, F2FS, and EXT4 were the fastest. https://www.phoronix.com/review/bcachefs-linux-67/2 Edit: The benchmarks were done with a debug variable set, which explains the weak IO. https://www.phoronix.com/news/Bcachefs-Updated-Linux-6.7 permalink fedilink source parent hideshow 2 child comments replies: [–] redcalcium@lemmy.institute 4 points 2 years ago* (2 children) Wait, so the benchmarks mostly contradict claims that bcachefs is almost as fast as ext4 except in application startup time? What kind of test performed for that application startup time benchmark? permalink fedilink source parent hideshow 4 child comments replies: [–] yote_zip@pawb.social 25 points 2 years ago (1 child) Note that in this benchmark, bcachefs had a debug variable turned on that allegedly severely hampered performance. Bcachefs has released an update to disable this variable but Phoronix hasn't redone benchmarks yet. I wouldn't put much value into any bcachefs-related comparisons from this current benchmark. permalink fedilink source parent hideshow 2 child comments replies: [–] Chewy7324@discuss.tchncs.de 2 points 2 years ago Interesting, that hopefully explains the weak IO troughput. Thank you. permalink fedilink source parent [–] ProtonBadger@kbin.social 2 points 2 years ago* The application startup test is designed to cold-load an application with heavy background IO going on. permalink fedilink source parent
[–] Chewy7324@discuss.tchncs.de 22 points 2 years ago* (last edited 2 years ago) (1 child) This screenshot is the only metric where btrfs is incredibly slow. Bcachefs random and sequential writes and reads are much slower than other filesystems in this benchmark. I have no idea how the actual real world performance will be. Bcachefs still misses a lot of features so I'll continue to follow the development, hopefully including performance improvements. Bcachefs sequential write performance in this out-of-the-box comparison was coming in at around half the speed of Btrfs while XFS, F2FS, and EXT4 were the fastest. https://www.phoronix.com/review/bcachefs-linux-67/2 Edit: The benchmarks were done with a debug variable set, which explains the weak IO. https://www.phoronix.com/news/Bcachefs-Updated-Linux-6.7 permalink fedilink source parent hideshow 2 child comments replies: [–] redcalcium@lemmy.institute 4 points 2 years ago* (2 children) Wait, so the benchmarks mostly contradict claims that bcachefs is almost as fast as ext4 except in application startup time? What kind of test performed for that application startup time benchmark? permalink fedilink source parent hideshow 4 child comments replies: [–] yote_zip@pawb.social 25 points 2 years ago (1 child) Note that in this benchmark, bcachefs had a debug variable turned on that allegedly severely hampered performance. Bcachefs has released an update to disable this variable but Phoronix hasn't redone benchmarks yet. I wouldn't put much value into any bcachefs-related comparisons from this current benchmark. permalink fedilink source parent hideshow 2 child comments replies: [–] Chewy7324@discuss.tchncs.de 2 points 2 years ago Interesting, that hopefully explains the weak IO troughput. Thank you. permalink fedilink source parent [–] ProtonBadger@kbin.social 2 points 2 years ago* The application startup test is designed to cold-load an application with heavy background IO going on. permalink fedilink source parent
[–] redcalcium@lemmy.institute 4 points 2 years ago* (2 children) Wait, so the benchmarks mostly contradict claims that bcachefs is almost as fast as ext4 except in application startup time? What kind of test performed for that application startup time benchmark? permalink fedilink source parent hideshow 4 child comments replies: [–] yote_zip@pawb.social 25 points 2 years ago (1 child) Note that in this benchmark, bcachefs had a debug variable turned on that allegedly severely hampered performance. Bcachefs has released an update to disable this variable but Phoronix hasn't redone benchmarks yet. I wouldn't put much value into any bcachefs-related comparisons from this current benchmark. permalink fedilink source parent hideshow 2 child comments replies: [–] Chewy7324@discuss.tchncs.de 2 points 2 years ago Interesting, that hopefully explains the weak IO troughput. Thank you. permalink fedilink source parent [–] ProtonBadger@kbin.social 2 points 2 years ago* The application startup test is designed to cold-load an application with heavy background IO going on. permalink fedilink source parent
[–] yote_zip@pawb.social 25 points 2 years ago (1 child) Note that in this benchmark, bcachefs had a debug variable turned on that allegedly severely hampered performance. Bcachefs has released an update to disable this variable but Phoronix hasn't redone benchmarks yet. I wouldn't put much value into any bcachefs-related comparisons from this current benchmark. permalink fedilink source parent hideshow 2 child comments replies: [–] Chewy7324@discuss.tchncs.de 2 points 2 years ago Interesting, that hopefully explains the weak IO troughput. Thank you. permalink fedilink source parent
[–] Chewy7324@discuss.tchncs.de 2 points 2 years ago Interesting, that hopefully explains the weak IO troughput. Thank you. permalink fedilink source parent
[–] ProtonBadger@kbin.social 2 points 2 years ago* The application startup test is designed to cold-load an application with heavy background IO going on. permalink fedilink source parent
