From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9180F18871F for ; Wed, 20 Nov 2024 08:15:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732090510; cv=none; b=ekI0kg7Tgvy71YDjvDAMklDLTqbQZ9ntZnv8dGx478VBAkI+L72+K6EpErWt8sUeWbbKTjbU/qJQZgVK2KNVTXPvqYP5OV294JqCck4J2dHgzmtF6DqACURD3cZykeiuxW4jA4T90gBk4w433bpCKH3NQktnHVw5AEXvXLgpkBA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732090510; c=relaxed/simple; bh=+ILn7l9xoJYN8Aice81GkTbQQFEOlF0scq3+2w9WoQY=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=uJUuy+4KovzNIyLciBcxfmga33mbtjryw2+apH/BEcE65Ypr+etc5+xbbbWQJy+LUsmDN6bqLc9+xrARtmIFeOmpR/Dj03inTFyNjCCOLre9EfwZQR2HNK5roULO5YBbZf54asxm1MV8+XSjCrq3Fr+A8v0oZUAWjnE/dpZLB54= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kEAicyZF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kEAicyZF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB7A8C4CECD; Wed, 20 Nov 2024 08:15:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1732090510; bh=+ILn7l9xoJYN8Aice81GkTbQQFEOlF0scq3+2w9WoQY=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=kEAicyZFCuOtaRZXlLTOmxFCV4j7YZ21P2IrwAVGlpGJYCFLVVyD+XD0plc/MCnzR 7QjnFldnDeD50Y3ywihEytVS3QaEeBTaGZmztfP1JEnJPEaal9WQ557bGkqagiRCgo +Vjk7vO2KV0KGJnCyw1KsXsJ4XtmrR6j76+jev/jHfcZQ4tDNE3h26Tl5BQ266wige troDzkWaY8MFW3K19QK8TOPQpBV7xjerSF7RKYtIp/YJZdplN8RCaLTGKz3+HbKlRV RFmMONn427A123Sck9y2Otb4LxY7SWdqN2uqOroGulg/wRhBrTRfXqNSy9KLVlHVPC rWy4cI2ENryQw== Message-ID: <5b40ca3c-efd6-4b50-8d11-845930a0e365@kernel.org> Date: Wed, 20 Nov 2024 16:15:05 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: Chao Yu , Xiuhong Wang , Xiuhong Wang , jaegeuk@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, hao_hao.wang@unisoc.com, ke.wang@unisoc.com Subject: Re: [PATCH] f2fs: Fix to avoid long time to shrink extent cache To: Zhiguo Niu References: <20241112110627.1314632-1-xiuhong.wang@unisoc.com> <5b0c17da-f1e1-490d-a560-3312bc8c3247@kernel.org> <65b89566-1038-4422-9e2e-4d7da26dd1c7@kernel.org> Content-Language: en-US From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2024/11/20 13:45, Zhiguo Niu wrote: > Chao Yu 于2024年11月20日周三 11:26写道： >> >> On 2024/11/19 16:26, Zhiguo Niu wrote: >>> Chao Yu 于2024年11月19日周二 15:50写道： >>>> >>>> On 2024/11/19 14:46, Xiuhong Wang wrote: >>>>> Chao Yu 于2024年11月19日周二 14:05写道： >>>>>> >>>>>> On 2024/11/12 19:06, Xiuhong Wang wrote: >>>>>>> We encountered a system hang problem based on the following >>>>>>> experiment: >>>>>>> There are 17 processes, 8 of which do 4k data read, write and >>>>>>> compare tests, and 8 do 64k read, write and compare tests. Each >>>>>>> thread writes a 256M file, and another thread writes a large file >>>>>>> to 80% of the disk, and then keeps doing read operations, all of >>>>>>> which are direct operations. This will cause the large file to be >>>>>>> filled to 80% of the disk to be severely fragmented. On a 512GB >>>>>>> device, this large file may generate a huge zombie extent tree. >>>>>>> >>>>>>> When system shutting down, the init process needs to wait for the >>>>>>> writeback process, and the writeback process may encounter the >>>>>>> situation where the READ_EXTENT_CACHE space is insufficient and >>>>>>> needs to free the zombie extent tree. The extent tree has a large >>>>>>> number of extent nodes, it will a long free time to free, which >>>>>>> triggers system hang. >>>>>> > > The stack when the problem occurs is as follows: >>>>>>> crash_arm64> bt 1 >>>>>>> PID: 1 TASK: ffffff80801a9200 CPU: 1 COMMAND: "init" >>>>>>> #0 [ffffffc00806b9a0] __switch_to at ffffffc00810711c >>>>>>> #1 [ffffffc00806ba00] __schedule at ffffffc0097c1c4c >>>>>>> #2 [ffffffc00806ba60] schedule at ffffffc0097c2308 >>>>>>> #3 [ffffffc00806bab0] wb_wait_for_completion at ffffffc0086320d4 >>>>>>> #4 [ffffffc00806bb20] writeback_inodes_sb at ffffffc00863719c >>>>>>> #5 [ffffffc00806bba0] sync_filesystem at ffffffc00863c98c >>>>>>> #6 [ffffffc00806bbc0] f2fs_quota_off_umount at ffffffc00886fc60 >>>>>>> #7 [ffffffc00806bc20] f2fs_put_super at ffffffc0088715b4 >>>>>>> #8 [ffffffc00806bc60] generic_shutdown_super at ffffffc0085cd61c >>>>>>> #9 [ffffffc00806bcd0] kill_f2fs_super at ffffffc00886b3dc >>>>>>> >>>>>>> crash_arm64> bt 14997 >>>>>>> PID: 14997 TASK: ffffff8119d82400 CPU: 3 COMMAND: "kworker/u16:0" >>>>>>> #0 [ffffffc019f8b760] __detach_extent_node at ffffffc0088d5a58 >>>>>>> #1 [ffffffc019f8b790] __release_extent_node at ffffffc0088d5970 >>>>>>> #2 [ffffffc019f8b810] f2fs_shrink_extent_tree at ffffffc0088d5c7c >>>>>>> #3 [ffffffc019f8b8a0] f2fs_balance_fs_bg at ffffffc0088c109c >>>>>>> #4 [ffffffc019f8b910] f2fs_write_node_pages at ffffffc0088bd4d8 >>>>>>> #5 [ffffffc019f8b990] do_writepages at ffffffc0084a0b5c >>>>>>> #6 [ffffffc019f8b9f0] __writeback_single_inode at ffffffc00862ee28 >>>>>>> #7 [ffffffc019f8bb30] writeback_sb_inodes at ffffffc0086358c0 >>>>>>> #8 [ffffffc019f8bc10] wb_writeback at ffffffc0086362dc >>>>>>> #9 [ffffffc019f8bcc0] wb_do_writeback at ffffffc008634910 >>>>>>> >>>>>>> Process 14997 ran for too long and caused the system hang. >>>>>>> >>>>>>> At this time, there are still 1086911 extent nodes in this zombie >>>>>>> extent tree that need to be cleaned up. >>>>>>> >>>>>>> crash_arm64_sprd_v8.0.3++> extent_tree.node_cnt ffffff80896cc500 >>>>>>> node_cnt = { >>>>>>> counter = 1086911 >>>>>>> }, >>>>>>> >>>>>>> The root cause of this problem is that when the f2fs_balance_fs >>>>>>> function is called in the write process, it will determine >>>>>>> whether to call f2fs_balance_fs_bg, but it is difficult to >>>>>>> meet the condition of excess_cached_nats. When the >>>>>>> f2fs_shrink_extent_tree function is called to free during >>>>>>> f2fs_write_node_pages, there are too many extent nodes on the >>>>>>> extent tree, which causes a loop and causes a system hang. >>>>>>> >>>>>>> To solve this problem, when calling f2fs_balance_fs, check whether >>>>>>> the extent cache is sufficient. If not, release the zombie extent >>>>>>> tree. >>>>>>> >>>>>>> Signed-off-by: Xiuhong Wang >>>>>>> Signed-off-by: Zhiguo Niu >>>>>>> --- >>>>>>> Test the problem with the temporary versions: >>>>>>> patch did not reproduce the problem, the patch is as follows: >>>>>>> @@ -415,7 +415,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need) >>>>>>> f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_FAULT_INJECT); >>>>>>> >>>>>>> /* balance_fs_bg is able to be pending */ >>>>>>> - if (need && excess_cached_nats(sbi)) >>>>>>> + if (need) >>>>>>> f2fs_balance_fs_bg(sbi, false); >>>>>>> >>>>>>> --- >>>>>>> fs/f2fs/segment.c | 4 +++- >>>>>>> 1 file changed, 3 insertions(+), 1 deletion(-) >>>>>>> >>>>>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c >>>>>>> index 1766254279d2..390bec177567 100644 >>>>>>> --- a/fs/f2fs/segment.c >>>>>>> +++ b/fs/f2fs/segment.c >>>>>>> @@ -415,7 +415,9 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need) >>>>>>> f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_FAULT_INJECT); >>>>>>> >>>>>>> /* balance_fs_bg is able to be pending */ >>>>>>> - if (need && excess_cached_nats(sbi)) >>>>>>> + if (need && (excess_cached_nats(sbi) || >>>>>>> + !f2fs_available_free_memory(sbi, READ_EXTENT_CACHE) || >>>>>>> + !f2fs_available_free_memory(sbi, AGE_EXTENT_CACHE))) >>>>>> >>>>>> Hi, >>>>>> >>>>>> I doubt if there is no enough memory, we may still run into >>>>>> f2fs_shrink_extent_tree() and suffer such long time delay. >>>>>> >>>>>> So, can we just let __free_extent_tree() break the loop once we have >>>>>> released entries w/ target number? something like this: >>>>>> >>>>>> --- >>>>>> fs/f2fs/extent_cache.c | 15 ++++++++++----- >>>>>> 1 file changed, 10 insertions(+), 5 deletions(-) >>>>>> >>>>>> diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c >>>>>> index 019c1f7b7fa5..38c71c1c4fb7 100644 >>>>>> --- a/fs/f2fs/extent_cache.c >>>>>> +++ b/fs/f2fs/extent_cache.c >>>>>> @@ -379,11 +379,12 @@ static struct extent_tree *__grab_extent_tree(struct inode *inode, >>>>>> } >>>>>> >>>>>> static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi, >>>>>> - struct extent_tree *et) >>>>>> + struct extent_tree *et, unsigned int nr_shrink) >>>>>> { >>>>>> struct rb_node *node, *next; >>>>>> struct extent_node *en; >>>>>> unsigned int count = atomic_read(&et->node_cnt); >>>>>> + unsigned int i = 0; >>>>>> >>>>>> node = rb_first_cached(&et->root); >>>>>> while (node) { >>>>>> @@ -391,6 +392,9 @@ static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi, >>>>>> en = rb_entry(node, struct extent_node, rb_node); >>>>>> __release_extent_node(sbi, et, en); >>>>>> node = next; >>>>>> + >>>>>> + if (nr_shrink && ++i >= nr_shrink) >>>>>> + break; >>>>>> } >>>>>> >>>>>> return count - atomic_read(&et->node_cnt); >>>>>> @@ -761,7 +765,7 @@ static void __update_extent_tree_range(struct inode *inode, >>>>>> } >>>>>> >>>>>> if (is_inode_flag_set(inode, FI_NO_EXTENT)) >>>>>> - __free_extent_tree(sbi, et); >>>>>> + __free_extent_tree(sbi, et, 0); >>>>>> >>>>>> if (et->largest_updated) { >>>>>> et->largest_updated = false; >>>>>> @@ -942,7 +946,8 @@ static unsigned int __shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink >>>>>> list_for_each_entry_safe(et, next, &eti->zombie_list, list) { >>>>>> if (atomic_read(&et->node_cnt)) { >>>>>> write_lock(&et->lock); >>>>>> - node_cnt += __free_extent_tree(sbi, et); >>>>>> + node_cnt += __free_extent_tree(sbi, et, >>>>>> + nr_shrink - node_cnt - tree_cnt); >>>>>> write_unlock(&et->lock); >>>>>> } >>>>>> f2fs_bug_on(sbi, atomic_read(&et->node_cnt)); >>>>>> @@ -1095,7 +1100,7 @@ static unsigned int __destroy_extent_node(struct inode *inode, >>>>>> return 0; >>>>>> >>>>>> write_lock(&et->lock); >>>>>> - node_cnt = __free_extent_tree(sbi, et); >>>>>> + node_cnt = __free_extent_tree(sbi, et, 0); >>>>>> write_unlock(&et->lock); >>>>>> >>>>>> return node_cnt; >>>>>> @@ -1117,7 +1122,7 @@ static void __drop_extent_tree(struct inode *inode, enum extent_type type) >>>>>> return; >>>>>> >>>>>> write_lock(&et->lock); >>>>>> - __free_extent_tree(sbi, et); >>>>>> + __free_extent_tree(sbi, et, 0); >>>>>> if (type == EX_READ) { >>>>>> set_inode_flag(inode, FI_NO_EXTENT); >>>>>> if (et->largest.len) { >>>>>> -- >>>>>> 2.40.1 >>>>>> >>>>>> Thanks, >>>>>> >>>>>>> f2fs_balance_fs_bg(sbi, false); >>>>>>> >>>>>>> if (!f2fs_is_checkpoint_ready(sbi)) >>>>>> >>>>> >>>>> >>>>> Hi chao, >>>>> >>>>> We have also considered this approach, but the problem still occurs >>>>> after retesting. >>>>> 1. The problem still occurs in the following call of the unmount data process. >>>>> f2fs_put_super -> f2fs_leave_shrinker >>>> >>>> Yes, I guess we need to fix this path as well, however, your patch didn't >>>> cover this path as well, am I missing something? >>> Dear Chao, >>> This patch version aim to shrink extent cache as early as possible on >>> the "all write path" >>> by "write action" -> f2fs_balance_fs -> f2fs_balance_fs_bg >> >> Zhiguo, thanks for explaining again. >> > Dear Chao, >> However, I doubt covering all write paths is not enough, because extent >> node can increase when f2fs_precache_extents() was called from paths >> including fadvise/fiemap/swapon/ioc_precache_extents, and there may be >> no writeback, so we may get no chance to call into f2fs_balance_fs_bg(), >> e.g. there is no data update in mountpoint, or mountpoint is readonly. > yes, Indeed it is. >> >>> As the comment , the "excess_cached_nats" is difficult to achieve in >>> this scenario, and >> >> Another concern is, in high-end products w/ more memory, it may has less >> chance to hit newly added condition in f2fs_balance_fs()? not sure though. > I also agree with this. > There is no other better idea for me(^^) excpetion for the two methods > we discussed above. > any good suggestions ? ^^ What do you think of this? From 8646c28027d5b050938335066ab56abbeca799e7 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Tue, 19 Nov 2024 11:53:09 +0800 Subject: [PATCH 1/2] f2fs: fix to shrink read extent node in batches Signed-off-by: Chao Yu --- fs/f2fs/extent_cache.c | 64 ++++++++++++++++++++++++------------------ 1 file changed, 37 insertions(+), 27 deletions(-) diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c index 019c1f7b7fa5..0c0d05f8551a 100644 --- a/fs/f2fs/extent_cache.c +++ b/fs/f2fs/extent_cache.c @@ -379,21 +379,22 @@ static struct extent_tree *__grab_extent_tree(struct inode *inode, } static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi, - struct extent_tree *et) + struct extent_tree *et, unsigned int nr_shrink) { struct rb_node *node, *next; struct extent_node *en; - unsigned int count = atomic_read(&et->node_cnt); + unsigned int count; node = rb_first_cached(&et->root); - while (node) { + + for (count = 0; node && count < nr_shrink; count++) { next = rb_next(node); en = rb_entry(node, struct extent_node, rb_node); __release_extent_node(sbi, et, en); node = next; } - return count - atomic_read(&et->node_cnt); + return count; } static void __drop_largest_extent(struct extent_tree *et, @@ -622,6 +623,30 @@ static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi, return en; } +static unsigned int __destroy_extent_node(struct inode *inode, + enum extent_type type) +{ + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); + struct extent_tree *et = F2FS_I(inode)->extent_tree[type]; + unsigned int nr_shrink = type == EX_READ ? + READ_EXTENT_CACHE_SHRINK_NUMBER : + AGE_EXTENT_CACHE_SHRINK_NUMBER; + unsigned int node_cnt = 0; + + if (!et || !atomic_read(&et->node_cnt)) + return 0; + + while (atomic_read(&et->node_cnt)) { + write_lock(&et->lock); + node_cnt = __free_extent_tree(sbi, et, nr_shrink); + write_unlock(&et->lock); + } + + f2fs_bug_on(sbi, atomic_read(&et->node_cnt)); + + return node_cnt; +} + static void __update_extent_tree_range(struct inode *inode, struct extent_info *tei, enum extent_type type) { @@ -760,9 +785,6 @@ static void __update_extent_tree_range(struct inode *inode, } } - if (is_inode_flag_set(inode, FI_NO_EXTENT)) - __free_extent_tree(sbi, et); - if (et->largest_updated) { et->largest_updated = false; updated = true; @@ -780,6 +802,9 @@ static void __update_extent_tree_range(struct inode *inode, out_read_extent_cache: write_unlock(&et->lock); + if (is_inode_flag_set(inode, FI_NO_EXTENT)) + __destroy_extent_node(inode, EX_READ); + if (updated) f2fs_mark_inode_dirty_sync(inode, true); } @@ -942,7 +967,8 @@ static unsigned int __shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink list_for_each_entry_safe(et, next, &eti->zombie_list, list) { if (atomic_read(&et->node_cnt)) { write_lock(&et->lock); - node_cnt += __free_extent_tree(sbi, et); + node_cnt += __free_extent_tree(sbi, et, + nr_shrink - node_cnt - tree_cnt); write_unlock(&et->lock); } f2fs_bug_on(sbi, atomic_read(&et->node_cnt)); @@ -1084,23 +1110,6 @@ unsigned int f2fs_shrink_age_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink return __shrink_extent_tree(sbi, nr_shrink, EX_BLOCK_AGE); } -static unsigned int __destroy_extent_node(struct inode *inode, - enum extent_type type) -{ - struct f2fs_sb_info *sbi = F2FS_I_SB(inode); - struct extent_tree *et = F2FS_I(inode)->extent_tree[type]; - unsigned int node_cnt = 0; - - if (!et || !atomic_read(&et->node_cnt)) - return 0; - - write_lock(&et->lock); - node_cnt = __free_extent_tree(sbi, et); - write_unlock(&et->lock); - - return node_cnt; -} - void f2fs_destroy_extent_node(struct inode *inode) { __destroy_extent_node(inode, EX_READ); @@ -1109,7 +1118,6 @@ void f2fs_destroy_extent_node(struct inode *inode) static void __drop_extent_tree(struct inode *inode, enum extent_type type) { - struct f2fs_sb_info *sbi = F2FS_I_SB(inode); struct extent_tree *et = F2FS_I(inode)->extent_tree[type]; bool updated = false; @@ -1117,7 +1125,6 @@ static void __drop_extent_tree(struct inode *inode, enum extent_type type) return; write_lock(&et->lock); - __free_extent_tree(sbi, et); if (type == EX_READ) { set_inode_flag(inode, FI_NO_EXTENT); if (et->largest.len) { @@ -1126,6 +1133,9 @@ static void __drop_extent_tree(struct inode *inode, enum extent_type type) } } write_unlock(&et->lock); + + __destroy_extent_node(inode, type); + if (updated) f2fs_mark_inode_dirty_sync(inode, true); } -- 2.40.1 From 3a1b7ec606d6211b2eaf72d148ebe52d38a0bf59 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Wed, 20 Nov 2024 15:37:22 +0800 Subject: [PATCH 2/2] f2fs: add a sysfs node to limit max read extent count per-inode Signed-off-by: Chao Yu --- Documentation/ABI/testing/sysfs-fs-f2fs | 6 ++++++ fs/f2fs/extent_cache.c | 5 ++++- fs/f2fs/f2fs.h | 4 ++++ fs/f2fs/sysfs.c | 7 +++++++ 4 files changed, 21 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs index 513296bb6f29..3e1630c70d8a 100644 --- a/Documentation/ABI/testing/sysfs-fs-f2fs +++ b/Documentation/ABI/testing/sysfs-fs-f2fs @@ -822,3 +822,9 @@ Description: It controls the valid block ratio threshold not to trigger excessiv for zoned deivces. The initial value of it is 95(%). F2FS will stop the background GC thread from intiating GC for sections having valid blocks exceeding the ratio. + +What: /sys/fs/f2fs//max_read_extent_count +Date: November 2024 +Contact: "Chao Yu" +Description: It controls max read extent count for per-inode, the value of threshold + is 10240 by default. diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c index 0c0d05f8551a..b08563ad010d 100644 --- a/fs/f2fs/extent_cache.c +++ b/fs/f2fs/extent_cache.c @@ -717,7 +717,9 @@ static void __update_extent_tree_range(struct inode *inode, } if (end < org_end && (type != EX_READ || - org_end - end >= F2FS_MIN_EXTENT_LEN)) { + (org_end - end >= F2FS_MIN_EXTENT_LEN && + atomic_read(&et->node_cnt) < + sbi->max_read_extent_count))) { if (parts) { __set_extent_info(&ei, end, org_end - end, @@ -1209,6 +1211,7 @@ void f2fs_init_extent_cache_info(struct f2fs_sb_info *sbi) sbi->hot_data_age_threshold = DEF_HOT_DATA_AGE_THRESHOLD; sbi->warm_data_age_threshold = DEF_WARM_DATA_AGE_THRESHOLD; sbi->last_age_weight = LAST_AGE_WEIGHT; + sbi->max_read_extent_count = DEF_MAX_READ_EXTENT_COUNT; } int __init f2fs_create_extent_cache(void) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index b65b023a588a..6f2cbf4c5740 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -635,6 +635,9 @@ enum { #define DEF_HOT_DATA_AGE_THRESHOLD 262144 #define DEF_WARM_DATA_AGE_THRESHOLD 2621440 +/* default max read extent count per inode */ +#define DEF_MAX_READ_EXTENT_COUNT 10240 + /* extent cache type */ enum extent_type { EX_READ, @@ -1619,6 +1622,7 @@ struct f2fs_sb_info { /* for extent tree cache */ struct extent_tree_info extent_tree[NR_EXTENT_CACHES]; atomic64_t allocated_data_blocks; /* for block age extent_cache */ + unsigned int max_read_extent_count; /* max read extent count per inode */ /* The threshold used for hot and warm data seperation*/ unsigned int hot_data_age_threshold; diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index bdbf24db667b..d1356c656cac 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -787,6 +787,13 @@ static ssize_t __sbi_store(struct f2fs_attr *a, return count; } + if (!strcmp(a->attr.name, "max_read_extent_count")) { + if (t > UINT_MAX) + return -EINVAL; + *ui = (unsigned int)t; + return count; + } + if (!strcmp(a->attr.name, "ipu_policy")) { if (t >= BIT(F2FS_IPU_MAX)) return -EINVAL; -- 2.40.1 > thanks！ >> >> + if (need && (excess_cached_nats(sbi) || >> + !f2fs_available_free_memory(sbi, READ_EXTENT_CACHE) || >> + !f2fs_available_free_memory(sbi, AGE_EXTENT_CACHE))) >> >> I mean will f2fs_available_free_memory(sbi, {READ,AGE}_EXTENT_CACHE) >> return true if available memory is sufficient? >> >> Thanks, >> >>> trigger the issue in path f2fs_write_node_pages->f2fs_balance_fs_bg(is >>> called directly here). >>> At that time, there were already a lot of extent node cnt. >>> Thanks! >>>> >>>>> 2. Writing back the inode in the normal write-back process will >>>>> release the extent cache, and the problem still occurs. The stack is >>>>> as follows: >>>> >>>> Ditto, >>>> >>>> Thanks, >>>> >>>>> [H 103098.974356] c2 [] (rb_erase+0x204/0x334) >>>>> [H 103098.974389] c2 [] (__release_extent_node+0xc8/0x168) >>>>> [H 103098.974425] c2 [] >>>>> (f2fs_update_extent_tree_range+0x4a0/0x724) >>>>> [H 103098.974459] c2 [] (f2fs_update_extent_cache+0x19c/0x1b0) >>>>> [H 103098.974495] c2 [] (f2fs_outplace_write_data+0x74/0xf0) >>>>> [H 103098.974525] c2 [] (f2fs_do_write_data_page+0x3e4/0x6c8) >>>>> [H 103098.974552] c2 [] >>>>> (f2fs_write_single_data_page+0x478/0xab0) >>>>> [H 103098.974574] c2 [] (f2fs_write_cache_pages+0x454/0xaac) >>>>> [H 103098.974596] c2 [] (__f2fs_write_data_pages+0x40c/0x4f0) >>>>> [H 103098.974617] c2 [] (f2fs_write_data_pages+0x30/0x40) >>>>> [H 103098.974645] c2 [] (do_writepages+0x18c/0x3e8) >>>>> [H 103098.974678] c2 [] (__writeback_single_inode+0x48/0x498) >>>>> [H 103098.974720] c2 [] (writeback_sb_inodes+0x454/0x9b0) >>>>> [H 103098.974754] c2 [] (__writeback_inodes_wb+0x198/0x224) >>>>> [H 103098.974788] c2 [] (wb_writeback+0x1c0/0x698) >>>>> [H 103098.974819] c2 [] (wb_do_writeback+0x420/0x54c) >>>>> [H 103098.974853] c2 [] (wb_workfn+0xe4/0x388) >>>> >>