From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
mikey@neuling.org, hbabu@us.ibm.com, nicholas.piggin@gmail.com,
linuxppc-dev@ozlabs.org, <linux-kernel@vger.kernel.org>
Subject: [PATCH v2 06/18] powerpc/vas: Reduce polling interval for busy state
Date: Fri, 6 Oct 2017 19:28:06 -0700 [thread overview]
Message-ID: <1507343298-27496-7-git-send-email-sukadev@linux.vnet.ibm.com> (raw)
In-Reply-To: <1507343298-27496-1-git-send-email-sukadev@linux.vnet.ibm.com>
A VAS window is normally in "busy" state for only a short duration.
Reduce the time we wait for the window to go to "not-busy" state to
speed-up vas_win_close() a bit.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/vas-window.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 95622a9..1422cdd 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -1060,21 +1060,23 @@ int vas_paste_crb(struct vas_window *txwin, int offset, bool re)
}
EXPORT_SYMBOL_GPL(vas_paste_crb);
+/*
+ * Wait for the window to go to "not-busy" state. It should only take a
+ * short time to queue a CRB, so window should not be busy for too long.
+ * Trying 5ms intervals.
+ */
static void poll_window_busy_state(struct vas_window *window)
{
int busy;
u64 val;
retry:
- /*
- * Poll Window Busy flag
- */
val = read_hvwc_reg(window, VREG(WIN_STATUS));
busy = GET_FIELD(VAS_WIN_BUSY, val);
if (busy) {
val = 0;
set_current_state(TASK_UNINTERRUPTIBLE);
- schedule_timeout(HZ);
+ schedule_timeout(msecs_to_jiffies(5));
goto retry;
}
}
--
2.7.4
next prev parent reply other threads:[~2017-10-07 2:31 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-07 2:28 [PATCH v2 00/18] powerpc/vas: Add support for FTW Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 01/18] powerpc/vas: init missing fields from [rt]xattr Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 02/18] powerpc/vas: Validate window credits Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 03/18] powerpc/vas: Cleanup some debug code Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 04/18] powerpc/vas: Drop poll_window_cast_out() Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 05/18] powerpc/vas: Use helper to unpin/close window Sukadev Bhattiprolu
2017-10-07 2:28 ` Sukadev Bhattiprolu [this message]
2017-10-07 2:28 ` [PATCH v2 07/18] powerpc/vas: Save configured window credits Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 08/18] powerpc/vas: poll for return of " Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 09/18] powerpc/vas: Create cpu to vas id mapping Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 10/18] powerpc/vas, nx-842: Define and use chip_to_vas_id() Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 11/18] powerpc/vas: Export HVWC to debugfs Sukadev Bhattiprolu
2017-11-07 12:19 ` Michael Ellerman
2017-10-07 2:28 ` [PATCH v2 12/18] powerpc: have copy depend on CONFIG_BOOK3S_64 Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 13/18] powerpc: Add support for setting SPRN_TIDR Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 14/18] powerpc: Define set_thread_used_vas() Sukadev Bhattiprolu
2017-11-07 0:49 ` Nicholas Piggin
2017-11-09 11:01 ` Michael Ellerman
2017-10-07 2:28 ` [PATCH v2 15/18] powerpc: Emulate paste instruction Sukadev Bhattiprolu
2017-10-09 10:00 ` Michael Neuling
2017-10-10 5:54 ` Michael Ellerman
2017-10-07 2:28 ` [PATCH v2 16/18] powerpc/vas: Define vas_win_paste_addr() Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 17/18] powerpc/vas: Define vas_win_id() Sukadev Bhattiprolu
2017-10-07 2:28 ` [PATCH v2 18/18] powerpc/vas: Add support for user receive window Sukadev Bhattiprolu
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