| Message ID | 1681882824-17532-1-git-send-email-zhaoyang.huang@unisoc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: skip CMA pages when they are not available | expand |
"zhaoyang.huang" <zhaoyang.huang@unisoc.com> writes: > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > It is wasting of effort to reclaim CMA pages if they are not availabe > for current context during direct reclaim. Skip them when under corresponding > circumstance. Do you have any performance number for this change? Best Regards, Huang, Ying > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > --- > mm/vmscan.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index bd6637f..04424d9 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2225,10 +2225,16 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan, > unsigned long nr_skipped[MAX_NR_ZONES] = { 0, }; > unsigned long skipped = 0; > unsigned long scan, total_scan, nr_pages; > + bool cma_cap = true; > + struct page *page; > LIST_HEAD(folios_skipped); > > total_scan = 0; > scan = 0; > + if ((IS_ENABLED(CONFIG_CMA)) && !current_is_kswapd() > + && (gfp_migratetype(sc->gfp_mask) != MIGRATE_MOVABLE)) > + cma_cap = false; > + > while (scan < nr_to_scan && !list_empty(src)) { > struct list_head *move_to = src; > struct folio *folio; > @@ -2239,7 +2245,10 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan, > nr_pages = folio_nr_pages(folio); > total_scan += nr_pages; > > - if (folio_zonenum(folio) > sc->reclaim_idx) { > + page = &folio->page; > + > + if (folio_zonenum(folio) > sc->reclaim_idx || > + (get_pageblock_migratetype(page) == MIGRATE_CMA && !cma_cap)) { > nr_skipped[folio_zonenum(folio)] += nr_pages; > move_to = &folios_skipped; > goto move;
On Wed, Apr 19, 2023 at 2:07 PM Huang, Ying <ying.huang@intel.com> wrote: > > "zhaoyang.huang" <zhaoyang.huang@unisoc.com> writes: > > > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > > > It is wasting of effort to reclaim CMA pages if they are not availabe > > for current context during direct reclaim. Skip them when under corresponding > > circumstance. > > Do you have any performance number for this change? Sorry, No. This patch arised from bellowing OOM issue which is caused by MIGRATE_CMA occupying almost 100 percent of zones free pages and solved by "168676649 mm,page_alloc,cma: conditionally prefer cma pageblocks for movable allocations". This could be a common scenario for a zone that has a large proportion of CMA reserved page blocks which need to be considered in both allocation and reclaiming perspective. 04166 < 4> [ 36.172486] [03-19 10:05:52.172] ActivityManager: page allocation failure: order:0, mode:0xc00(GFP_NOIO), nodemask=(null),cpuset=foreground,mems_allowed=0 0419C < 4> [ 36.189447] [03-19 10:05:52.189] DMA32: 0*4kB 447*8kB (C) 217*16kB (C) 124*32kB (C) 136*64kB (C) 70*128kB (C) 22*256kB (C) 3*512kB (C) 0*1024kB 0*2048kB 0*4096kB = 35848kB 0419D < 4> [ 36.193125] [03-19 10:05:52.193] Normal: 231*4kB (UMEH) 49*8kB (MEH) 14*16kB (H) 13*32kB (H) 8*64kB (H) 2*128kB (H) 0*256kB 1*512kB (H) 0*1024kB 0*2048kB 0*4096kB = 3236kB ...... 041EA < 4> [ 36.234447] [03-19 10:05:52.234] SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC) 041EB < 4> [ 36.234455] [03-19 10:05:52.234] cache: ext4_io_end, object size: 64, buffer size: 64, default order: 0, min order: 0 041EC < 4> [ 36.234459] [03-19 10:05:52.234] node 0: slabs: 53, objs: 3392, free: 0 > > Best Regards, > Huang, Ying > > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > --- > > mm/vmscan.c | 11 ++++++++++- > > 1 file changed, 10 insertions(+), 1 deletion(-) > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index bd6637f..04424d9 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -2225,10 +2225,16 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan, > > unsigned long nr_skipped[MAX_NR_ZONES] = { 0, }; > > unsigned long skipped = 0; > > unsigned long scan, total_scan, nr_pages; > > + bool cma_cap = true; > > + struct page *page; > > LIST_HEAD(folios_skipped); > > > > total_scan = 0; > > scan = 0; > > + if ((IS_ENABLED(CONFIG_CMA)) && !current_is_kswapd() > > + && (gfp_migratetype(sc->gfp_mask) != MIGRATE_MOVABLE)) > > + cma_cap = false; > > + > > while (scan < nr_to_scan && !list_empty(src)) { > > struct list_head *move_to = src; > > struct folio *folio; > > @@ -2239,7 +2245,10 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan, > > nr_pages = folio_nr_pages(folio); > > total_scan += nr_pages; > > > > - if (folio_zonenum(folio) > sc->reclaim_idx) { > > + page = &folio->page; > > + > > + if (folio_zonenum(folio) > sc->reclaim_idx || > > + (get_pageblock_migratetype(page) == MIGRATE_CMA && !cma_cap)) { > > nr_skipped[folio_zonenum(folio)] += nr_pages; > > move_to = &folios_skipped; > > goto move;
Zhaoyang Huang <huangzhaoyang@gmail.com> writes: > On Wed, Apr 19, 2023 at 2:07 PM Huang, Ying <ying.huang@intel.com> wrote: >> >> "zhaoyang.huang" <zhaoyang.huang@unisoc.com> writes: >> >> > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> >> > >> > It is wasting of effort to reclaim CMA pages if they are not availabe >> > for current context during direct reclaim. Skip them when under corresponding >> > circumstance. >> >> Do you have any performance number for this change? > Sorry, No. This patch arised from bellowing OOM issue which is caused > by MIGRATE_CMA occupying almost 100 percent of zones free pages and > solved by "168676649 mm,page_alloc,cma: conditionally prefer cma > pageblocks for movable allocations". This could be a common scenario > for a zone that has a large proportion of CMA reserved page blocks > which need to be considered in both allocation and reclaiming > perspective. IIUC, your patch is inspired by the OOM issue and the commit 168676649? Anyway, I think it's better for you to describe the issues you want to address in the patch description, and show how your patch addresses it with some tests if possible. Performance number is just one way to show it. Best Regards, Huang, Ying > 04166 < 4> [ 36.172486] [03-19 10:05:52.172] ActivityManager: page > allocation failure: order:0, mode:0xc00(GFP_NOIO), > nodemask=(null),cpuset=foreground,mems_allowed=0 > 0419C < 4> [ 36.189447] [03-19 10:05:52.189] DMA32: 0*4kB 447*8kB > (C) 217*16kB (C) 124*32kB (C) 136*64kB (C) 70*128kB (C) 22*256kB (C) > 3*512kB (C) 0*1024kB 0*2048kB 0*4096kB = 35848kB > 0419D < 4> [ 36.193125] [03-19 10:05:52.193] Normal: 231*4kB (UMEH) > 49*8kB (MEH) 14*16kB (H) 13*32kB (H) 8*64kB (H) 2*128kB (H) 0*256kB > 1*512kB (H) 0*1024kB 0*2048kB 0*4096kB = 3236kB > ...... > 041EA < 4> [ 36.234447] [03-19 10:05:52.234] SLUB: Unable to > allocate memory on node -1, gfp=0xa20(GFP_ATOMIC) > 041EB < 4> [ 36.234455] [03-19 10:05:52.234] cache: ext4_io_end, > object size: 64, buffer size: 64, default order: 0, min order: 0 > 041EC < 4> [ 36.234459] [03-19 10:05:52.234] node 0: slabs: 53, > objs: 3392, free: 0 >> >> Best Regards, >> Huang, Ying >> >> > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> >> > --- >> > mm/vmscan.c | 11 ++++++++++- >> > 1 file changed, 10 insertions(+), 1 deletion(-) >> > >> > diff --git a/mm/vmscan.c b/mm/vmscan.c >> > index bd6637f..04424d9 100644 >> > --- a/mm/vmscan.c >> > +++ b/mm/vmscan.c >> > @@ -2225,10 +2225,16 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan, >> > unsigned long nr_skipped[MAX_NR_ZONES] = { 0, }; >> > unsigned long skipped = 0; >> > unsigned long scan, total_scan, nr_pages; >> > + bool cma_cap = true; >> > + struct page *page; >> > LIST_HEAD(folios_skipped); >> > >> > total_scan = 0; >> > scan = 0; >> > + if ((IS_ENABLED(CONFIG_CMA)) && !current_is_kswapd() >> > + && (gfp_migratetype(sc->gfp_mask) != MIGRATE_MOVABLE)) >> > + cma_cap = false; >> > + >> > while (scan < nr_to_scan && !list_empty(src)) { >> > struct list_head *move_to = src; >> > struct folio *folio; >> > @@ -2239,7 +2245,10 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan, >> > nr_pages = folio_nr_pages(folio); >> > total_scan += nr_pages; >> > >> > - if (folio_zonenum(folio) > sc->reclaim_idx) { >> > + page = &folio->page; >> > + >> > + if (folio_zonenum(folio) > sc->reclaim_idx || >> > + (get_pageblock_migratetype(page) == MIGRATE_CMA && !cma_cap)) { >> > nr_skipped[folio_zonenum(folio)] += nr_pages; >> > move_to = &folios_skipped; >> > goto move;
Hi zhaoyang.huang,
kernel test robot noticed the following build errors:
[auto build test ERROR on akpm-mm/mm-everything]
url: https://github.com/intel-lab-lkp/linux/commits/zhaoyang-huang/mm-skip-CMA-pages-when-they-are-not-available/20230419-134421
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/1681882824-17532-1-git-send-email-zhaoyang.huang%40unisoc.com
patch subject: [PATCH] mm: skip CMA pages when they are not available
config: i386-randconfig-a012-20230417 (https://download.01.org/0day-ci/archive/20230419/202304191908.Bqx6phWT-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/346b74f2bf2155cb8be6af66b346157c7681b9c9
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review zhaoyang-huang/mm-skip-CMA-pages-when-they-are-not-available/20230419-134421
git checkout 346b74f2bf2155cb8be6af66b346157c7681b9c9
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304191908.Bqx6phWT-lkp@intel.com/
All errors (new ones prefixed by >>):
>> mm/vmscan.c:2317:40: error: use of undeclared identifier 'MIGRATE_CMA'; did you mean 'MIGRATE_SYNC'?
(get_pageblock_migratetype(page) == MIGRATE_CMA && !cma_cap)) {
^~~~~~~~~~~
MIGRATE_SYNC
include/linux/migrate_mode.h:18:2: note: 'MIGRATE_SYNC' declared here
MIGRATE_SYNC,
^
1 error generated.
vim +2317 mm/vmscan.c
2261
2262 /*
2263 * Isolating page from the lruvec to fill in @dst list by nr_to_scan times.
2264 *
2265 * lruvec->lru_lock is heavily contended. Some of the functions that
2266 * shrink the lists perform better by taking out a batch of pages
2267 * and working on them outside the LRU lock.
2268 *
2269 * For pagecache intensive workloads, this function is the hottest
2270 * spot in the kernel (apart from copy_*_user functions).
2271 *
2272 * Lru_lock must be held before calling this function.
2273 *
2274 * @nr_to_scan: The number of eligible pages to look through on the list.
2275 * @lruvec: The LRU vector to pull pages from.
2276 * @dst: The temp list to put pages on to.
2277 * @nr_scanned: The number of pages that were scanned.
2278 * @sc: The scan_control struct for this reclaim session
2279 * @lru: LRU list id for isolating
2280 *
2281 * returns how many pages were moved onto *@dst.
2282 */
2283 static unsigned long isolate_lru_folios(unsigned long nr_to_scan,
2284 struct lruvec *lruvec, struct list_head *dst,
2285 unsigned long *nr_scanned, struct scan_control *sc,
2286 enum lru_list lru)
2287 {
2288 struct list_head *src = &lruvec->lists[lru];
2289 unsigned long nr_taken = 0;
2290 unsigned long nr_zone_taken[MAX_NR_ZONES] = { 0 };
2291 unsigned long nr_skipped[MAX_NR_ZONES] = { 0, };
2292 unsigned long skipped = 0;
2293 unsigned long scan, total_scan, nr_pages;
2294 bool cma_cap = true;
2295 struct page *page;
2296 LIST_HEAD(folios_skipped);
2297
2298 total_scan = 0;
2299 scan = 0;
2300 if ((IS_ENABLED(CONFIG_CMA)) && !current_is_kswapd()
2301 && (gfp_migratetype(sc->gfp_mask) != MIGRATE_MOVABLE))
2302 cma_cap = false;
2303
2304 while (scan < nr_to_scan && !list_empty(src)) {
2305 struct list_head *move_to = src;
2306 struct folio *folio;
2307
2308 folio = lru_to_folio(src);
2309 prefetchw_prev_lru_folio(folio, src, flags);
2310
2311 nr_pages = folio_nr_pages(folio);
2312 total_scan += nr_pages;
2313
2314 page = &folio->page;
2315
2316 if (folio_zonenum(folio) > sc->reclaim_idx ||
> 2317 (get_pageblock_migratetype(page) == MIGRATE_CMA && !cma_cap)) {
2318 nr_skipped[folio_zonenum(folio)] += nr_pages;
2319 move_to = &folios_skipped;
2320 goto move;
2321 }
2322
2323 /*
2324 * Do not count skipped folios because that makes the function
2325 * return with no isolated folios if the LRU mostly contains
2326 * ineligible folios. This causes the VM to not reclaim any
2327 * folios, triggering a premature OOM.
2328 * Account all pages in a folio.
2329 */
2330 scan += nr_pages;
2331
2332 if (!folio_test_lru(folio))
2333 goto move;
2334 if (!sc->may_unmap && folio_mapped(folio))
2335 goto move;
2336
2337 /*
2338 * Be careful not to clear the lru flag until after we're
2339 * sure the folio is not being freed elsewhere -- the
2340 * folio release code relies on it.
2341 */
2342 if (unlikely(!folio_try_get(folio)))
2343 goto move;
2344
2345 if (!folio_test_clear_lru(folio)) {
2346 /* Another thread is already isolating this folio */
2347 folio_put(folio);
2348 goto move;
2349 }
2350
2351 nr_taken += nr_pages;
2352 nr_zone_taken[folio_zonenum(folio)] += nr_pages;
2353 move_to = dst;
2354 move:
2355 list_move(&folio->lru, move_to);
2356 }
2357
2358 /*
2359 * Splice any skipped folios to the start of the LRU list. Note that
2360 * this disrupts the LRU order when reclaiming for lower zones but
2361 * we cannot splice to the tail. If we did then the SWAP_CLUSTER_MAX
2362 * scanning would soon rescan the same folios to skip and waste lots
2363 * of cpu cycles.
2364 */
2365 if (!list_empty(&folios_skipped)) {
2366 int zid;
2367
2368 list_splice(&folios_skipped, src);
2369 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
2370 if (!nr_skipped[zid])
2371 continue;
2372
2373 __count_zid_vm_events(PGSCAN_SKIP, zid, nr_skipped[zid]);
2374 skipped += nr_skipped[zid];
2375 }
2376 }
2377 *nr_scanned = total_scan;
2378 trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan,
2379 total_scan, skipped, nr_taken,
2380 sc->may_unmap ? 0 : ISOLATE_UNMAPPED, lru);
2381 update_lru_sizes(lruvec, lru, nr_zone_taken);
2382 return nr_taken;
2383 }
2384
diff --git a/mm/vmscan.c b/mm/vmscan.c index bd6637f..04424d9 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2225,10 +2225,16 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan, unsigned long nr_skipped[MAX_NR_ZONES] = { 0, }; unsigned long skipped = 0; unsigned long scan, total_scan, nr_pages; + bool cma_cap = true; + struct page *page; LIST_HEAD(folios_skipped); total_scan = 0; scan = 0; + if ((IS_ENABLED(CONFIG_CMA)) && !current_is_kswapd() + && (gfp_migratetype(sc->gfp_mask) != MIGRATE_MOVABLE)) + cma_cap = false; + while (scan < nr_to_scan && !list_empty(src)) { struct list_head *move_to = src; struct folio *folio; @@ -2239,7 +2245,10 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan, nr_pages = folio_nr_pages(folio); total_scan += nr_pages; - if (folio_zonenum(folio) > sc->reclaim_idx) { + page = &folio->page; + + if (folio_zonenum(folio) > sc->reclaim_idx || + (get_pageblock_migratetype(page) == MIGRATE_CMA && !cma_cap)) { nr_skipped[folio_zonenum(folio)] += nr_pages; move_to = &folios_skipped; goto move;