From: Patrick Farrell <pfarrell@whamcloud.com>
Date: Tue, 29 Aug 2023 21:01:45 +0000 (-0400)
Subject: LU-13814 osc: reduce usage of cdp_cl_pages array
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=refs%2Fchanges%2F64%2F52164%2F19;p=fs%2Flustre-release.git

LU-13814 osc: reduce usage of cdp_cl_pages array

The cdp_cl_pages array is how we are still keeping cl_pages
available, so reducing use of it is the next step.

This is the start of that process, in this case in
osc_queue_dio_pages.

Test-Parameters: fortestonly
Test-Parameters: forjanitoronly
Signed-off-by: Patrick Farrell <pfarrell@whamcloud.com>
Change-Id: Ifd2f5ad63b20df8475f83447a6d9b3d56be3ca70
---

diff --git a/lustre/osc/osc_cache.c b/lustre/osc/osc_cache.c
index e2d0498..27e4e1f 100644
--- a/lustre/osc/osc_cache.c
+++ b/lustre/osc/osc_cache.c
@@ -2542,10 +2542,10 @@ int osc_queue_dio_pages(const struct lu_env *env, struct cl_io *io,
 	struct cl_page *page;
 	struct osc_page *opg;
 	int mppr = cli->cl_max_pages_per_rpc;
+	int page_count = to_page - from_page + 1;
 	pgoff_t start = CL_PAGE_EOF;
 	bool can_merge = true;
 	enum cl_req_type crt;
-	int page_count = 0;
 	pgoff_t end = 0;
 	int i;
 	ENTRY;
@@ -2555,6 +2555,15 @@ int osc_queue_dio_pages(const struct lu_env *env, struct cl_io *io,
 	else
 		crt = CRT_WRITE;
 
+	/* we should never have more pages than can fit in an RPC, but if we do
+	 * we must allow sending of a larger RPC
+	 */
+	while (page_count > mppr)
+		mppr = mppr << 1;
+
+	if (unlikely(cdp->cdp_from > 0 || cdp->cdp_to < PAGE_SIZE - 1))
+		can_merge = false;
+
 	for (i = from_page; i <= to_page; i++) {
 		pgoff_t index;
 
@@ -2567,11 +2576,6 @@ int osc_queue_dio_pages(const struct lu_env *env, struct cl_io *io,
 			end = index;
 		if (index < start)
 			start = index;
-		++page_count;
-		mppr <<= (page_count > mppr);
-
-		if (unlikely(oap->oap_count < PAGE_SIZE))
-			can_merge = false;
 	}
 
 	ext = osc_extent_alloc(obj);