The branch main has been updated by dougm: URL: https://cgit.FreeBSD.org/src/commit/?id=6d86bdf1c423e162cecd9b7c516b211461d1932b
commit 6d86bdf1c423e162cecd9b7c516b211461d1932b Author: Doug Moore <[email protected]> AuthorDate: 2024-08-02 02:36:44 +0000 Commit: Doug Moore <[email protected]> CommitDate: 2024-08-02 02:36:44 +0000 vm_pageout: shrink pageout array The array passed to vm_pageout_flush, and constructed in a middle-out fashion, can never use array element zero. Shrink the array by one, and reduce indices by one, to save that bit of stack space. In the vm_object version, make the accounting look more like the pageout version. Reported by: alc Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D46208 --- sys/vm/vm_object.c | 17 +++++++++-------- sys/vm/vm_pageout.c | 6 +++--- 2 files changed, 12 insertions(+), 11 deletions(-) diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c index be21081255c2..7b3950b6f3bc 100644 --- a/sys/vm/vm_object.c +++ b/sys/vm/vm_object.c @@ -1115,13 +1115,14 @@ static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags, int flags, boolean_t *allclean, boolean_t *eio) { - vm_page_t ma[2 * vm_pageout_page_count], tp; - int count, mreq, runlen; + vm_page_t ma[2 * vm_pageout_page_count - 1], tp; + int base, count, runlen; vm_page_lock_assert(p, MA_NOTOWNED); vm_page_assert_xbusied(p); VM_OBJECT_ASSERT_WLOCKED(object); - ma[vm_pageout_page_count] = p; + base = nitems(ma) / 2; + ma[base] = p; for (count = 1, tp = p; count < vm_pageout_page_count; count++) { tp = vm_page_next(tp); if (tp == NULL || vm_page_tryxbusy(tp) == 0) @@ -1130,10 +1131,10 @@ vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags, vm_page_xunbusy(tp); break; } - ma[vm_pageout_page_count + count] = tp; + ma[base + count] = tp; } - for (mreq = 0, tp = p; count < vm_pageout_page_count; count++, mreq++) { + for (tp = p; count < vm_pageout_page_count; count++) { tp = vm_page_prev(tp); if (tp == NULL || vm_page_tryxbusy(tp) == 0) break; @@ -1141,11 +1142,11 @@ vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags, vm_page_xunbusy(tp); break; } - ma[vm_pageout_page_count - 1 - mreq] = tp; + ma[--base] = tp; } - vm_pageout_flush(&ma[vm_pageout_page_count - mreq], count, pagerflags, - mreq, &runlen, eio); + vm_pageout_flush(&ma[base], count, pagerflags, nitems(ma) / 2 - base, + &runlen, eio); return (runlen); } diff --git a/sys/vm/vm_pageout.c b/sys/vm/vm_pageout.c index e848d68739ca..8ad4bf4d3ab4 100644 --- a/sys/vm/vm_pageout.c +++ b/sys/vm/vm_pageout.c @@ -348,7 +348,7 @@ static int vm_pageout_cluster(vm_page_t m) { vm_object_t object; - vm_page_t mc[2 * vm_pageout_page_count], p, pb, ps; + vm_page_t mc[2 * vm_pageout_page_count - 1], p, pb, ps; vm_pindex_t pindex; int ib, is, page_base, pageout_count; @@ -358,9 +358,9 @@ vm_pageout_cluster(vm_page_t m) vm_page_assert_xbusied(m); - mc[vm_pageout_page_count] = pb = ps = m; pageout_count = 1; - page_base = vm_pageout_page_count; + page_base = nitems(mc) / 2; + mc[page_base] = pb = ps = m; ib = 1; is = 1;
