diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2021-07-31 09:14:46 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-07-31 09:14:46 -0700 |
| commit | d2e11fd2b7fcd10b7bcef418c55490c934aa94e8 (patch) | |
| tree | bdce7769cd4d69b375aad004e844d1a413863485 /kernel/trace/ring_buffer.c | |
| parent | aae950b189413ed3201354600d44223da0bcf63c (diff) | |
| parent | c7d102232649226a69dddd58a4942cf13cff4f7c (diff) | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicting commits, all resolutions pretty trivial:
drivers/bus/mhi/pci_generic.c
5c2c85315948 ("bus: mhi: pci-generic: configurable network interface MRU")
56f6f4c4eb2a ("bus: mhi: pci_generic: Apply no-op for wake using sideband wake boolean")
drivers/nfc/s3fwrn5/firmware.c
a0302ff5906a ("nfc: s3fwrn5: remove unnecessary label")
46573e3ab08f ("nfc: s3fwrn5: fix undefined parameter values in dev_err()")
801e541c79bb ("nfc: s3fwrn5: fix undefined parameter values in dev_err()")
MAINTAINERS
7d901a1e878a ("net: phy: add Maxlinear GPY115/21x/24x driver")
8a7b46fa7902 ("MAINTAINERS: add Yasushi SHOJI as reviewer for the Microchip CAN BUS Analyzer Tool driver")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'kernel/trace/ring_buffer.c')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index d1463eac11a3..e592d1df6f88 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3880,10 +3880,30 @@ static bool rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer) if (unlikely(!head)) return true; - return reader->read == rb_page_commit(reader) && - (commit == reader || - (commit == head && - head->read == rb_page_commit(commit))); + /* Reader should exhaust content in reader page */ + if (reader->read != rb_page_commit(reader)) + return false; + + /* + * If writers are committing on the reader page, knowing all + * committed content has been read, the ring buffer is empty. + */ + if (commit == reader) + return true; + + /* + * If writers are committing on a page other than reader page + * and head page, there should always be content to read. + */ + if (commit != head) + return false; + + /* + * Writers are committing on the head page, we just need + * to care about there're committed data, and the reader will + * swap reader page with head page when it is to read data. + */ + return rb_page_commit(commit) == 0; } /** |