* [patch 0/2] adaptive readahead fixes [not found] <20061129111416.430835000@intel.ustc.edu.cn> @ 2006-11-29 11:14 ` Fengguang Wu [not found] ` <20061129112948.751104000@intel.ustc.edu.cn> [not found] ` <20061129112948.946621000@intel.ustc.edu.cn> 2 siblings, 0 replies; 3+ messages in thread From: Fengguang Wu @ 2006-11-29 11:14 UTC (permalink / raw) To: Andrew Morton; +Cc: Neil Brown, linux-kernel Andrew, Here are two bug fix patches against -mm, with their recommended placement: readahead-events-accounting.patch readahead-rescue_pages.patch readahead-sysctl-parameters.patch +readahead-sysctl-parameters-fix.patch readahead-min-max-sizes.patch readahead-state-based-method-aging-accounting.patch readahead-state-based-method-routines.patch readahead-loop-case.patch readahead-nfsd-case.patch readahead-nfsd-case-fix.patch +readahead-nfsd-case-fix-uninitialized-ra_min-ra_max.patch readahead-turn-on-by-default.patch readahead-remove-size-limit-on-read_ahead_kb.patch readahead-remove-size-limit-of-max_sectors_kb-on-read_ahead_kb.patch readahead-sysctl-parameters-fix.patch ===================================== Two trivial fixes. // Was three, but you were so swift on CTL_UNNUMBERED :-) readahead-nfsd-case-fix-uninitialized-ra_min-ra_max.patch ========================================================= The NFS benchmark is ran again with the bug fixed. The summary is included in the patch as changelog. The raw numbers are here: pattern=f rsize=8k ratio=1 3.04s clock 0.64s kernel 0.01s user 224+1987 cs ratio=1 3.06s clock 0.66s kernel 0.02s user 199+2340 cs ratio=1 3.10s clock 0.63s kernel 0.02s user 254+2264 cs ratio=50 2.59s clock 0.60s kernel 0.02s user 106+1180 cs ratio=50 2.43s clock 0.59s kernel 0.01s user 94+1189 cs ratio=50 2.50s clock 0.59s kernel 0.02s user 98+1174 cs pattern=f rsize=32k ratio=1 2.39s clock 0.29s kernel 0.02s user 1046+59 cs ratio=1 2.40s clock 0.29s kernel 0.01s user 1040+69 cs ratio=1 2.41s clock 0.28s kernel 0.02s user 1114+55 cs ratio=50 2.18s clock 0.32s kernel 0.02s user 227+213 cs ratio=50 2.15s clock 0.32s kernel 0.02s user 230+215 cs ratio=50 2.17s clock 0.33s kernel 0.01s user 225+208 cs pattern=f rsize=128k ratio=1 2.42s clock 0.32s kernel 0.01s user 436+131 cs ratio=1 2.38s clock 0.33s kernel 0.02s user 441+128 cs ratio=1 2.39s clock 0.31s kernel 0.01s user 448+122 cs ratio=50 2.36s clock 0.30s kernel 0.01s user 202+67 cs ratio=50 2.21s clock 0.31s kernel 0.02s user 194+72 cs ratio=50 2.47s clock 0.30s kernel 0.01s user 201+63 cs pattern=ff rsize=8k ratio=1 12.19s clock 1.18s kernel 0.38s user 4152+13042 cs ratio=1 12.88s clock 1.21s kernel 0.33s user 4564+12574 cs ratio=1 12.26s clock 1.22s kernel 0.38s user 4857+12453 cs ratio=50 6.53s clock 1.27s kernel 0.32s user 174+2256 cs ratio=50 6.33s clock 1.27s kernel 0.33s user 164+2252 cs ratio=50 6.35s clock 1.24s kernel 0.35s user 151+2264 cs pattern=ff rsize=32k ratio=1 14.49s clock 0.90s kernel 0.37s user 2904+9906 cs ratio=1 14.55s clock 1.00s kernel 0.34s user 2899+9803 cs ratio=1 14.81s clock 1.00s kernel 0.31s user 2910+10147 cs ratio=50 5.48s clock 0.65s kernel 0.30s user 177+512 cs ratio=50 5.42s clock 0.68s kernel 0.29s user 181+509 cs ratio=50 5.47s clock 0.65s kernel 0.29s user 175+521 cs pattern=ff rsize=128k ratio=1 15.87s clock 0.90s kernel 0.32s user 1496+8738 cs ratio=1 15.33s clock 0.89s kernel 0.34s user 1718+8350 cs ratio=1 16.17s clock 0.91s kernel 0.32s user 1706+7959 cs ratio=50 5.18s clock 0.56s kernel 0.28s user 175+255 cs ratio=50 5.22s clock 0.57s kernel 0.30s user 172+258 cs ratio=50 5.16s clock 0.54s kernel 0.30s user 168+260 cs pattern=d rsize=8k ratio=1 2.86s clock 0.45s kernel 0.07s user 7961+729 cs ratio=1 2.87s clock 0.50s kernel 0.07s user 8036+627 cs ratio=1 2.80s clock 0.51s kernel 0.07s user 7986+640 cs ratio=50 2.58s clock 0.51s kernel 0.07s user 8873+177 cs ratio=50 2.39s clock 0.51s kernel 0.05s user 8782+194 cs ratio=50 2.48s clock 0.51s kernel 0.06s user 8884+171 cs pattern=d rsize=32k ratio=1 2.49s clock 0.40s kernel 0.05s user 7428+83 cs ratio=1 2.57s clock 0.40s kernel 0.06s user 7425+86 cs ratio=1 2.54s clock 0.41s kernel 0.06s user 7427+83 cs ratio=50 2.02s clock 0.40s kernel 0.08s user 7478+169 cs ratio=50 1.99s clock 0.43s kernel 0.05s user 7488+162 cs ratio=50 1.95s clock 0.39s kernel 0.05s user 7483+169 cs pattern=d rsize=128k ratio=1 2.17s clock 0.41s kernel 0.05s user 7248+120 cs ratio=1 2.13s clock 0.42s kernel 0.05s user 7242+133 cs ratio=1 2.23s clock 0.43s kernel 0.07s user 7247+121 cs ratio=50 2.09s clock 0.39s kernel 0.06s user 7315+97 cs ratio=50 1.93s clock 0.41s kernel 0.05s user 7314+131 cs ratio=50 1.97s clock 0.43s kernel 0.07s user 7317+132 cs pattern=dd rsize=8k ratio=1 8.23s clock 1.04s kernel 0.18s user 15564+1306 cs ratio=1 8.20s clock 1.06s kernel 0.17s user 15465+1251 cs ratio=1 8.04s clock 1.03s kernel 0.15s user 15487+1226 cs ratio=50 8.06s clock 1.03s kernel 0.18s user 16992+291 cs ratio=50 8.14s clock 0.98s kernel 0.19s user 17011+297 cs ratio=50 7.77s clock 1.01s kernel 0.16s user 16920+292 cs pattern=dd rsize=32k ratio=1 8.46s clock 0.91s kernel 0.16s user 14248+593 cs ratio=1 8.27s clock 0.85s kernel 0.17s user 14266+564 cs ratio=1 8.09s clock 0.86s kernel 0.18s user 14255+551 cs ratio=50 6.85s clock 0.89s kernel 0.18s user 14304+301 cs ratio=50 6.79s clock 0.93s kernel 0.14s user 14302+274 cs ratio=50 6.99s clock 0.93s kernel 0.17s user 14296+303 cs pattern=dd rsize=128k ratio=1 7.87s clock 0.88s kernel 0.17s user 13845+368 cs ratio=1 7.81s clock 0.89s kernel 0.17s user 13853+393 cs ratio=1 7.57s clock 0.90s kernel 0.17s user 13838+433 cs ratio=50 6.97s clock 0.84s kernel 0.19s user 13816+235 cs ratio=50 6.90s clock 0.88s kernel 0.19s user 13816+225 cs ratio=50 7.03s clock 0.84s kernel 0.18s user 13813+222 cs Regards, Fengguang Wu PS. About the partial sendfile problem mentioned in the previous benchmark mail: The stock readahead is not handling it correctly, but not so destructive. So I choose not to submit the patch. ^ permalink raw reply [flat|nested] 3+ messages in thread
[parent not found: <20061129112948.751104000@intel.ustc.edu.cn>]
* [patch 1/2] readahead sysctl parameters fix [not found] ` <20061129112948.751104000@intel.ustc.edu.cn> @ 2006-11-29 11:14 ` Fengguang Wu 0 siblings, 0 replies; 3+ messages in thread From: Fengguang Wu @ 2006-11-29 11:14 UTC (permalink / raw) To: Andrew Morton; +Cc: Neil Brown, linux-kernel [-- Attachment #1: readahead-sysctl-parameters-fix.patch --] [-- Type: text/plain, Size: 1350 bytes --] - do no extra readahead when (readahead_ratio == 1) - define readahead_hit_rate inside CONFIG_ADAPTIVE_READAHEAD ifdefs Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> --- --- linux-2.6.19-rc6-mm1.orig/include/linux/mm.h +++ linux-2.6.19-rc6-mm1/include/linux/mm.h @@ -1074,7 +1074,7 @@ extern int readahead_ratio; static inline int prefer_adaptive_readahead(void) { - return readahead_ratio > 1; + return readahead_ratio != 1; } /* Do stack extension */ --- linux-2.6.19-rc6-mm1.orig/Documentation/sysctl/vm.txt +++ linux-2.6.19-rc6-mm1/Documentation/sysctl/vm.txt @@ -234,7 +234,7 @@ plenty of memory(>>2MB per reader), a bi readahead_ratio also selects the readahead logic: VALUE CODE PATH ------------------------------------------- - 0 disable readahead totally + 0 read as is, no extra readahead 1 select the stock readahead logic 2-100 select the adaptive readahead logic --- linux-2.6.19-rc6-mm1.orig/mm/readahead.c +++ linux-2.6.19-rc6-mm1/mm/readahead.c @@ -40,10 +40,10 @@ /* Set read-ahead size to ##% of the thrashing-threshold. */ int readahead_ratio = 50; EXPORT_SYMBOL_GPL(readahead_ratio); -#endif /* Readahead as long as cache hit ratio keeps above 1/##. */ int readahead_hit_rate = 0; +#endif /* CONFIG_ADAPTIVE_READAHEAD */ /* * Detailed classification of read-ahead behaviors. -- ^ permalink raw reply [flat|nested] 3+ messages in thread
[parent not found: <20061129112948.946621000@intel.ustc.edu.cn>]
* [patch 2/2] readahead nfsd case: fix uninitialized ra_min/ra_max [not found] ` <20061129112948.946621000@intel.ustc.edu.cn> @ 2006-11-29 11:14 ` Fengguang Wu 0 siblings, 0 replies; 3+ messages in thread From: Fengguang Wu @ 2006-11-29 11:14 UTC (permalink / raw) To: Andrew Morton; +Cc: Neil Brown, linux-kernel [-- Attachment #1: readahead-nfsd-case-fix-uninitialized-ra_min-ra_max.patch --] [-- Type: text/plain, Size: 2256 bytes --] ra_min/ra_max are not initialized, fix it. New benchmark numbers on hda: ST3250820A, ATA DISK drive hda: max request size: 512KiB hda: 488397168 sectors (250059 MB) w/8192KiB Cache, CHS=30401/255/63, UDMA(100) with nfs mount mount -o tcp,rsize=$((rsize<<10)) localhost:$EXPORT $MNT rsize stock adaptive ================================== f 8k 3.07 2.51 -18.2% 32k 2.40 2.17 -9.6% 128k 2.40 2.35 -2.1% ff 8k 12.44 6.40 -48.6% 32k 14.62 5.46 -62.7% 128k 15.79 5.19 -67.1% d 8k 2.84 2.48 -12.7% 32k 2.53 1.99 -21.3% 128k 2.18 2.00 -8.3% dd 8k 8.16 7.99 -2.1% 32k 8.27 6.88 -16.8% 128k 7.75 6.97 -10.1% The 4 patterns tested are: f: single file read ff: double file parallel read d: single dir read dd: double dir parallel read Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> --- --- linux-2.6.19-rc6-mm1.orig/mm/readahead.c +++ linux-2.6.19-rc6-mm1/mm/readahead.c @@ -1616,6 +1616,10 @@ page_cache_readahead_adaptive(struct add unsigned long ra_max; int ret; + /* no read-ahead */ + if (!ra->ra_pages) + return 0; + if (page) { ClearPageReadahead(page); @@ -1635,9 +1639,6 @@ page_cache_readahead_adaptive(struct add offset + LAPTOP_POLL_INTERVAL)) return 0; } - } else if (ra->flags & RA_FLAG_NFSD) { /* nfsd read */ - ra_size = max_sane_readahead(req_size); - goto readit; } if (page) @@ -1647,11 +1648,13 @@ page_cache_readahead_adaptive(struct add get_readahead_bounds(ra, &ra_min, &ra_max); - /* read-ahead disabled? */ - if (unlikely(!ra_max || !readahead_ratio)) { - ra_size = max_sane_readahead(req_size); + /* read as is */ + if (!readahead_ratio) + goto readit; + + /* nfsd read */ + if (!page && (ra->flags & RA_FLAG_NFSD)) goto readit; - } /* * Start of file. @@ -1698,11 +1701,11 @@ page_cache_readahead_adaptive(struct add return 0; } +readit: /* * Random read. */ ra_size = min(req_size, ra_max); -readit: ra_size = __do_page_cache_readahead(mapping, filp, offset, ra_size, 0); ra_account(ra, RA_EVENT_RANDOM_READ, ra_size); -- ^ permalink raw reply [flat|nested] 3+ messages in thread
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2006-11-29 11:14 ` [patch 0/2] adaptive readahead fixes Fengguang Wu
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2006-11-29 11:14 ` [patch 1/2] readahead sysctl parameters fix Fengguang Wu
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2006-11-29 11:14 ` [patch 2/2] readahead nfsd case: fix uninitialized ra_min/ra_max Fengguang Wu
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