From: Joel Fernandes <joelaf@google.com>
To: linux-kernel@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>,
Joel Fernandes <joelaf@google.com>,
Anton Vorontsov <anton@enomsg.org>,
Colin Cross <ccross@android.com>, Tony Luck <tony.luck@intel.com>
Subject: [PATCH v2 1/7] pstore: Make spinlock per zone instead of global
Date: Thu, 20 Oct 2016 00:34:00 -0700 [thread overview]
Message-ID: <1476948846-15006-2-git-send-email-joelaf@google.com> (raw)
In-Reply-To: <1476948846-15006-1-git-send-email-joelaf@google.com>
Currently pstore has a global spinlock for all zones. Since the zones are
independent and modify different areas of memory, there's no need to have a
global lock, so we should use a per-zone lock as introduced here. Also,
ramoops's ftrace usecase has a FTRACE_PER_CPU flag introduced in this patch
series which splits the ftrace memory area into a single zone per CPU thus
eliminating the need for locking. In preparation for this, make the locking
optional.
Signed-off-by: Joel Fernandes <joelaf@google.com>
---
fs/pstore/ram_core.c | 11 +++++------
include/linux/pstore_ram.h | 1 +
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 3975dee..cb92055 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -48,8 +48,6 @@ static inline size_t buffer_start(struct persistent_ram_zone *prz)
return atomic_read(&prz->buffer->start);
}
-static DEFINE_RAW_SPINLOCK(buffer_lock);
-
/* increase and wrap the start pointer, returning the old value */
static size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
{
@@ -57,7 +55,7 @@ static size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
int new;
unsigned long flags;
- raw_spin_lock_irqsave(&buffer_lock, flags);
+ raw_spin_lock_irqsave(&prz->buffer_lock, flags);
old = atomic_read(&prz->buffer->start);
new = old + a;
@@ -65,7 +63,7 @@ static size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
new -= prz->buffer_size;
atomic_set(&prz->buffer->start, new);
- raw_spin_unlock_irqrestore(&buffer_lock, flags);
+ raw_spin_unlock_irqrestore(&prz->buffer_lock, flags);
return old;
}
@@ -77,7 +75,7 @@ static void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
size_t new;
unsigned long flags;
- raw_spin_lock_irqsave(&buffer_lock, flags);
+ raw_spin_lock_irqsave(&prz->buffer_lock, flags);
old = atomic_read(&prz->buffer->size);
if (old == prz->buffer_size)
@@ -89,7 +87,7 @@ static void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
atomic_set(&prz->buffer->size, new);
exit:
- raw_spin_unlock_irqrestore(&buffer_lock, flags);
+ raw_spin_unlock_irqrestore(&prz->buffer_lock, flags);
}
static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
@@ -493,6 +491,7 @@ static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig,
prz->buffer->sig = sig;
persistent_ram_zap(prz);
+ prz->buffer_lock = __RAW_SPIN_LOCK_UNLOCKED(buffer_lock);
return 0;
}
diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h
index c668c86..244d242 100644
--- a/include/linux/pstore_ram.h
+++ b/include/linux/pstore_ram.h
@@ -40,6 +40,7 @@ struct persistent_ram_zone {
void *vaddr;
struct persistent_ram_buffer *buffer;
size_t buffer_size;
+ raw_spinlock_t buffer_lock;
/* ECC correction */
char *par_buffer;
--
2.7.4
next prev parent reply other threads:[~2016-10-20 7:34 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-20 7:33 [PATCH v2 0/7] pstore: Improve performance of ftrace backend with ramoops Joel Fernandes
2016-10-20 7:34 ` Joel Fernandes [this message]
2016-11-11 0:06 ` [PATCH v2 1/7] pstore: Make spinlock per zone instead of global Kees Cook
2016-11-11 0:24 ` Joel Fernandes
2016-10-20 7:34 ` [PATCH v2 2/7] pstore: locking: dont lock unless caller asks to Joel Fernandes
2016-11-11 0:10 ` Kees Cook
2016-11-11 18:16 ` Kees Cook
2016-10-20 7:34 ` [PATCH v2 3/7] pstore: Warn for the case of PSTORE_TYPE_PMSG write using deprecated function Joel Fernandes
2016-11-11 0:10 ` Kees Cook
2016-10-20 7:34 ` [PATCH v2 4/7] pstore: Make ramoops_init_przs generic for other prz arrays Joel Fernandes
2016-11-11 0:12 ` Kees Cook
2016-10-20 7:34 ` [PATCH v2 5/7] ramoops: Split ftrace buffer space into per-CPU zones Joel Fernandes
2016-11-11 0:13 ` Kees Cook
2016-11-11 0:16 ` Joel Fernandes
2016-11-11 18:27 ` Kees Cook
2016-10-20 7:34 ` [PATCH v2 6/7] pstore: Add support to store timestamp counter in ftrace records Joel Fernandes
2016-11-11 0:15 ` Kees Cook
2016-11-11 0:21 ` Joel Fernandes
2016-11-11 18:29 ` Kees Cook
2016-10-20 7:34 ` [PATCH v2 7/7] pstore: Merge per-CPU ftrace zones into one zone for output Joel Fernandes
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