| Message ID | 1497455067-6050-1-git-send-email-jeffm@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 6/14/17 11:44 AM, jeffm@suse.com wrote: > From: Jeff Mahoney <jeffm@suse.com> > > In a heavy write scenario, we can end up with a large number of pinned > bytes. This can translate into (very) premature ENOSPC because pinned > bytes must be accounted for when allowing a reservation but aren't > accounted for when deciding whether to create a new chunk. > > This patch adds the accounting to should_alloc_chunk so that we can > create the chunk. > > Signed-off-by: Jeff Mahoney <jeffm@suse.com> > --- > fs/btrfs/extent-tree.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index cb0b924..d027807 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -4389,7 +4389,7 @@ static int should_alloc_chunk(struct btrfs_fs_info *fs_info, > { > struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; > u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly; > - u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved; > + u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned + sinfo->bytes_may_use; > u64 thresh; > > if (force == CHUNK_ALLOC_FORCE) > Ignore this patch. It certainly allocates chunks more aggressively, but it means we end up with a ton of metadata chunks even when we don't have much metadata. -Jeff
On 06/21/2017 04:14 PM, Jeff Mahoney wrote: > On 6/14/17 11:44 AM, jeffm@suse.com wrote: >> From: Jeff Mahoney <jeffm@suse.com> >> >> In a heavy write scenario, we can end up with a large number of pinned >> bytes. This can translate into (very) premature ENOSPC because pinned >> bytes must be accounted for when allowing a reservation but aren't >> accounted for when deciding whether to create a new chunk. >> >> This patch adds the accounting to should_alloc_chunk so that we can >> create the chunk. >> >> Signed-off-by: Jeff Mahoney <jeffm@suse.com> >> --- >> fs/btrfs/extent-tree.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c >> index cb0b924..d027807 100644 >> --- a/fs/btrfs/extent-tree.c >> +++ b/fs/btrfs/extent-tree.c >> @@ -4389,7 +4389,7 @@ static int should_alloc_chunk(struct btrfs_fs_info *fs_info, >> { >> struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; >> u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly; >> - u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved; >> + u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned + sinfo->bytes_may_use; >> u64 thresh; >> >> if (force == CHUNK_ALLOC_FORCE) >> > > > Ignore this patch. It certainly allocates chunks more aggressively, but > it means we end up with a ton of metadata chunks even when we don't have > much metadata. > Josef and I pushed this needle back and forth a bunch of times in the early days. I still think we can allocate a few more chunks than we do now... -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 6/21/17 4:31 PM, Chris Mason wrote: > On 06/21/2017 04:14 PM, Jeff Mahoney wrote: >> On 6/14/17 11:44 AM, jeffm@suse.com wrote: >>> From: Jeff Mahoney <jeffm@suse.com> >>> >>> In a heavy write scenario, we can end up with a large number of pinned >>> bytes. This can translate into (very) premature ENOSPC because pinned >>> bytes must be accounted for when allowing a reservation but aren't >>> accounted for when deciding whether to create a new chunk. >>> >>> This patch adds the accounting to should_alloc_chunk so that we can >>> create the chunk. >>> >>> Signed-off-by: Jeff Mahoney <jeffm@suse.com> >>> --- >>> fs/btrfs/extent-tree.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c >>> index cb0b924..d027807 100644 >>> --- a/fs/btrfs/extent-tree.c >>> +++ b/fs/btrfs/extent-tree.c >>> @@ -4389,7 +4389,7 @@ static int should_alloc_chunk(struct >>> btrfs_fs_info *fs_info, >>> { >>> struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; >>> u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly; >>> - u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved; >>> + u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved + >>> sinfo->bytes_pinned + sinfo->bytes_may_use; >>> u64 thresh; >>> >>> if (force == CHUNK_ALLOC_FORCE) >>> >> >> >> Ignore this patch. It certainly allocates chunks more aggressively, but >> it means we end up with a ton of metadata chunks even when we don't have >> much metadata. >> > > Josef and I pushed this needle back and forth a bunch of times in the > early days. I still think we can allocate a few more chunks than we do > now... I agree. This patch was to fix an issue that we are seeing during installation. It'd stop with ENOSPC with >50GB completely unallocated. The patch passed the test cases that were failing before but now it's failing differently. I was worried this pattern might be the end result: Data,single: Size:4.00GiB, Used:3.32GiB /dev/vde 4.00GiB Metadata,DUP: Size:20.00GiB, Used:204.12MiB /dev/vde 40.00GiB System,DUP: Size:8.00MiB, Used:16.00KiB /dev/vde 16.00MiB This is on a fresh file system with just "cp /usr /mnt" executed. I'm looking into it a bit more now. -Jeff
On 06/21/2017 05:08 PM, Jeff Mahoney wrote: > On 6/21/17 4:31 PM, Chris Mason wrote: >> On 06/21/2017 04:14 PM, Jeff Mahoney wrote: >>> On 6/14/17 11:44 AM, jeffm@suse.com wrote: >>>> From: Jeff Mahoney <jeffm@suse.com> >>>> >>>> In a heavy write scenario, we can end up with a large number of pinned >>>> bytes. This can translate into (very) premature ENOSPC because pinned >>>> bytes must be accounted for when allowing a reservation but aren't >>>> accounted for when deciding whether to create a new chunk. >>>> >>>> This patch adds the accounting to should_alloc_chunk so that we can >>>> create the chunk. >>>> >>>> Signed-off-by: Jeff Mahoney <jeffm@suse.com> >>>> --- >>>> fs/btrfs/extent-tree.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c >>>> index cb0b924..d027807 100644 >>>> --- a/fs/btrfs/extent-tree.c >>>> +++ b/fs/btrfs/extent-tree.c >>>> @@ -4389,7 +4389,7 @@ static int should_alloc_chunk(struct >>>> btrfs_fs_info *fs_info, >>>> { >>>> struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; >>>> u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly; >>>> - u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved; >>>> + u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved + >>>> sinfo->bytes_pinned + sinfo->bytes_may_use; >>>> u64 thresh; >>>> >>>> if (force == CHUNK_ALLOC_FORCE) >>>> >>> >>> >>> Ignore this patch. It certainly allocates chunks more aggressively, but >>> it means we end up with a ton of metadata chunks even when we don't have >>> much metadata. >>> >> >> Josef and I pushed this needle back and forth a bunch of times in the >> early days. I still think we can allocate a few more chunks than we do >> now... > > I agree. This patch was to fix an issue that we are seeing during > installation. It'd stop with ENOSPC with >50GB completely unallocated. > The patch passed the test cases that were failing before but now it's > failing differently. I was worried this pattern might be the end result: > > Data,single: Size:4.00GiB, Used:3.32GiB > /dev/vde 4.00GiB > > Metadata,DUP: Size:20.00GiB, Used:204.12MiB > /dev/vde 40.00GiB > > System,DUP: Size:8.00MiB, Used:16.00KiB > /dev/vde 16.00MiB > > This is on a fresh file system with just "cp /usr /mnt" executed. > > I'm looking into it a bit more now. Does this failure still happen with Omar's ENOSPC fix (commit: 70e7af244f24c94604ef6eca32ad297632018583) -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 6/21/17 5:15 PM, Chris Mason wrote: > > > On 06/21/2017 05:08 PM, Jeff Mahoney wrote: >> On 6/21/17 4:31 PM, Chris Mason wrote: >>> On 06/21/2017 04:14 PM, Jeff Mahoney wrote: >>>> On 6/14/17 11:44 AM, jeffm@suse.com wrote: >>>>> From: Jeff Mahoney <jeffm@suse.com> >>>>> >>>>> In a heavy write scenario, we can end up with a large number of pinned >>>>> bytes. This can translate into (very) premature ENOSPC because pinned >>>>> bytes must be accounted for when allowing a reservation but aren't >>>>> accounted for when deciding whether to create a new chunk. >>>>> >>>>> This patch adds the accounting to should_alloc_chunk so that we can >>>>> create the chunk. >>>>> >>>>> Signed-off-by: Jeff Mahoney <jeffm@suse.com> >>>>> --- >>>>> fs/btrfs/extent-tree.c | 2 +- >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>>> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c >>>>> index cb0b924..d027807 100644 >>>>> --- a/fs/btrfs/extent-tree.c >>>>> +++ b/fs/btrfs/extent-tree.c >>>>> @@ -4389,7 +4389,7 @@ static int should_alloc_chunk(struct >>>>> btrfs_fs_info *fs_info, >>>>> { >>>>> struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; >>>>> u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly; >>>>> - u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved; >>>>> + u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved + >>>>> sinfo->bytes_pinned + sinfo->bytes_may_use; >>>>> u64 thresh; >>>>> >>>>> if (force == CHUNK_ALLOC_FORCE) >>>>> >>>> >>>> >>>> Ignore this patch. It certainly allocates chunks more aggressively, >>>> but >>>> it means we end up with a ton of metadata chunks even when we don't >>>> have >>>> much metadata. >>>> >>> >>> Josef and I pushed this needle back and forth a bunch of times in the >>> early days. I still think we can allocate a few more chunks than we do >>> now... >> >> I agree. This patch was to fix an issue that we are seeing during >> installation. It'd stop with ENOSPC with >50GB completely unallocated. >> The patch passed the test cases that were failing before but now it's >> failing differently. I was worried this pattern might be the end result: >> >> Data,single: Size:4.00GiB, Used:3.32GiB >> /dev/vde 4.00GiB >> >> Metadata,DUP: Size:20.00GiB, Used:204.12MiB >> /dev/vde 40.00GiB >> >> System,DUP: Size:8.00MiB, Used:16.00KiB >> /dev/vde 16.00MiB >> >> This is on a fresh file system with just "cp /usr /mnt" executed. >> >> I'm looking into it a bit more now. > > Does this failure still happen with Omar's ENOSPC fix (commit: > 70e7af244f24c94604ef6eca32ad297632018583) Nope. There aren't any warnings either with or without my patch. Adding Omar's didn't make a difference. -Jeff
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index cb0b924..d027807 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4389,7 +4389,7 @@ static int should_alloc_chunk(struct btrfs_fs_info *fs_info, { struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly; - u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved; + u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned + sinfo->bytes_may_use; u64 thresh; if (force == CHUNK_ALLOC_FORCE)