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authorHaren Myneni <haren@linux.ibm.com>2020-04-15 23:06:59 -0700
committerMichael Ellerman <mpe@ellerman.id.au>2020-04-20 16:53:01 +1000
commitbd4da68dbd5fd2e83841b3500ac575967a948cfa (patch)
treeea37b353a7878fa9f36487a0c7ed0dade49d5617 /arch/powerpc/platforms/powernv/vas-window.c
parent04f6296ca7c34cbc78e077518c634cc5c392b3ec (diff)
powerpc/vas: Display process stuck message
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> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1587017219.2275.1073.camel@hbabu-laptop
Diffstat (limited to 'arch/powerpc/platforms/powernv/vas-window.c')
-rw-r--r--arch/powerpc/platforms/powernv/vas-window.c30
1 files changed, 29 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 4b5adf521882..d0c07cf03f68 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -1181,6 +1181,7 @@ 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)
@@ -1199,10 +1200,27 @@ retry:
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 % 1000))
+ pr_warn_ratelimited("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;
}
}
@@ -1216,6 +1234,7 @@ 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));
@@ -1223,7 +1242,16 @@ retry:
if (busy) {
val = 0;
set_current_state(TASK_UNINTERRUPTIBLE);
- schedule_timeout(msecs_to_jiffies(5));
+ schedule_timeout(msecs_to_jiffies(10));
+ count++;
+ /*
+ * Takes around few milliseconds to process all pending
+ * requests.
+ */
+ if (!(count % 1000))
+ pr_warn_ratelimited("VAS: pid %d stuck. Window (ID=%d) is in busy state. Retries %d\n",
+ vas_window_pid(window), window->winid, count);
+
goto retry;
}
}