From: Haren Myneni <haren@linux.ibm.com>
To: mpe@ellerman.id.au
Cc: npiggin@gmail.com, mikey@neuling.org,
herbert@gondor.apana.org.au, frederic.barrat@fr.ibm.com,
srikar@linux.vnet.ibm.com, linux-kernel@vger.kernel.org,
hch@infradead.org, oohall@gmail.com, clg@kaod.org,
sukadev@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org,
ajd@linux.ibm.com
Subject: [PATCH v9 12/13] powerpc/vas: Display process stuck message
Date: Wed, 01 Apr 2020 14:31:34 -0700 [thread overview]
Message-ID: <1585776694.10664.456.camel@hbabu-laptop> (raw)
In-Reply-To: <1585775978.10664.438.camel@hbabu-laptop>
Process can not close send window until all requests are processed.
Means wait until window state is not busy and send credits are
returned. Display debug messages in case taking longer to close the
window.
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
arch/powerpc/platforms/powernv/vas-window.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 084e76b..c8644c3 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -1182,6 +1182,7 @@ static void poll_window_credits(struct vas_window *window)
{
u64 val;
int creds, mode;
+ int count = 0;
val = read_hvwc_reg(window, VREG(WINCTL));
if (window->tx_win)
@@ -1200,10 +1201,27 @@ static void poll_window_credits(struct vas_window *window)
creds = GET_FIELD(VAS_LRX_WCRED, val);
}
+ /*
+ * Takes around few milliseconds to complete all pending requests
+ * and return credits.
+ * TODO: Scan fault FIFO and invalidate CRBs points to this window
+ * and issue CRB Kill to stop all pending requests. Need only
+ * if there is a bug in NX or fault handling in kernel.
+ */
if (creds < window->wcreds_max) {
val = 0;
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(msecs_to_jiffies(10));
+ count++;
+ /*
+ * Process can not close send window until all credits are
+ * returned.
+ */
+ if (!(count % 10000))
+ pr_debug("VAS: pid %d stuck. Waiting for credits returned for Window(%d). creds %d, Retries %d\n",
+ vas_window_pid(window), window->winid,
+ creds, count);
+
goto retry;
}
}
@@ -1217,6 +1235,7 @@ static void poll_window_busy_state(struct vas_window *window)
{
int busy;
u64 val;
+ int count = 0;
retry:
val = read_hvwc_reg(window, VREG(WIN_STATUS));
@@ -1225,6 +1244,15 @@ static void poll_window_busy_state(struct vas_window *window)
val = 0;
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(msecs_to_jiffies(5));
+ count++;
+ /*
+ * Takes around few milliseconds to process all pending
+ * requests.
+ */
+ if (!(count % 10000))
+ pr_debug("VAS: pid %d stuck. Window (ID=%d) is in busy state. Retries %d\n",
+ vas_window_pid(window), window->winid, count);
+
goto retry;
}
}
--
1.8.3.1
next prev parent reply other threads:[~2020-04-01 21:32 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-01 21:19 [PATCH v9 00/13] powerpc/vas: Page fault handling for user space NX requests Haren Myneni
2020-04-01 21:25 ` [PATCH v9 01/13] powerpc/xive: Define xive_native_alloc_irq_on_chip() Haren Myneni
2020-04-01 21:25 ` [PATCH v9 02/13] powerpc/vas: Define nx_fault_stamp in coprocessor_request_block Haren Myneni
2020-04-01 21:26 ` [PATCH v9 03/13] powerpc/vas: Alloc and setup IRQ and trigger port address Haren Myneni
2020-04-01 21:26 ` [PATCH v9 04/13] powerpc/vas: Setup fault window per VAS instance Haren Myneni
2020-04-01 21:27 ` [PATCH v9 05/13] powerpc/vas: Register NX with fault window ID and IRQ port value Haren Myneni
2020-04-01 21:28 ` [PATCH 06/13] powerpc/vas: Take reference to PID and mm for user space windows Haren Myneni
2020-04-01 22:13 ` [PATCH v9 " Haren Myneni
2020-04-01 21:28 ` [PATCH v9 07/13] powerpc/vas: Setup thread IRQ handler per VAS instance Haren Myneni
2020-04-01 21:29 ` [PATCH v9 08/13] powerpc/vas: Update CSB and notify process for fault CRBs Haren Myneni
2020-04-01 21:29 ` [PATCH v9 09/13] powerpc/vas: Return credits after handling fault Haren Myneni
2020-04-01 21:30 ` [PATCH v9 10/13] powerpc/vas: Print CRB and FIFO values Haren Myneni
2020-04-01 21:31 ` [PATCH v9 11/13] powerpc/vas: Do not use default credits for receive window Haren Myneni
2020-04-01 21:31 ` Haren Myneni [this message]
2020-04-01 21:32 ` [PATCH v9 13/13] powerpc/vas: Free send window in VAS instance after credits returned Haren Myneni
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